Search Results

Search found 3443 results on 138 pages for 'byte'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 83/138 | < Previous Page | 79 80 81 82 83 84 85 86 87 88 89 90  | Next Page >

  • Using .align in inline assemby

    - by tech74
    Hi, I'm using ".align 16 \n\t" in some inline ARM assembly that is implementing some loops to align it on a 16 byte boundary however gcc asm compiler is complaining that alignement is too large i want to implement -falign-loops=16 in asm for a particular loop Thanks

    Read the article

  • DataOutputStream, does it lose some bits

    - by user308806
    hello, I'm writing a client server application, but I don't receive the same bytes at the client side when they are sent from the server side. At the server side I used .write(bytes[]) method. At the client side, I used .readFully(byte[]) method. Do you have any idea ?

    Read the article

  • Java execution details in System.out

    - by John
    As I remember there is a magic command line option in Java that turn on writing of operations that are currently executed to console. The output was looked like byte code. I do not mean -verbose, because it prints only class loading, while this option outputs information like memory allocation etc.

    Read the article

  • EndOfStreamException caused by spammer (c#/asp.net)

    - by maxp
    I have a contact page on my site that seems to have been latched on to by a spammer. The error itself is: System.IO.EndOfStreamException: Unable to read beyond the end of the stream. at System.IO.BinaryReader.ReadByte() at System.Web.UI.ObjectStateFormatter.DeserializeIndexedString(SerializerBinaryReader reader, Byte token) at System.Web.UI.ObjectStateFormatter.DeserializeValue(SerializerBinaryReader reader) Google turns up little. I assume they are submitting an invalid viewstate, but the exception has no line number so im stumped.

    Read the article

  • Converting IL to C# code

    - by Praveen
    Hi All, I need to convert the IL to c# code. I have an assembly and I am reading this assembly. I get MethodBody from MethodInfo and the methodbody has a method GetILAsByteArraY() which returns a byte array now I want to comvert this IL to C# code. Please help me out in solving this.

    Read the article

  • how to do event based serial port reading in c?

    - by moon
    i want to read serial port when there is some data present i mean on the event when data arrives only then i will read serial port instead of continuously reading the port i have this code for continuous reading the port how can i make it event based. thanx in advance. while(1) { bReadRC = ReadFile(m_hCom, &byte, 6, &iBytesRead, NULL); printf("Data Recieved Through Serial port and no. of Bytes Recieved is %d",iBytesRead); }

    Read the article

  • Integer to Character conversion in C

    - by nthrgeek
    Lets us consider this snippet: int s; scanf("%c",&s); Here I have used int, and not char, for variable s, now for using s for character conversion safely I have to make it char again because when scanf reads a character it only overwrites one byte of the variable it is assigning it to, and not all four that int has. For conversion I could use s = (char)s; as the next line, but is it possible to implement the same by subtracting something from s ?

    Read the article

  • Comparing arrays with sql

    - by Nissim
    I want to perform a 'SELECT' statement with a byte array (binary) parameter as a condition. I tried to google it, but didn't find anything useful. In general, I keep information of files in the database. one of the properties is the file's hash (binary). I want to give a hash to the SELECT statement, and get all rows with the same hash value.

    Read the article

  • Can SQLite file copied successfully on the data folder of an unrooted android device ?

    - by student
    I know that in order to access the data folder on the device, it needs to be rooted. However, if I just want to copy the database from my assets folder to the data folder on my device, will the copying process works on an unrooted phone? The following is my Database Helper class. From logcat, I can verify that the methods call to copyDataBase(), createDataBase() and openDataBase() are returned successfully. However, I got this error message android.database.sqlite.SQLiteException: no such table: TABLE_NAME: when my application is executing rawQuery. I'm suspecting the database file is not copied successfully (cannot be too sure as I do not have access to data folder), yet the method call to copyDatabase() are not throwing any exception. What could it be? Thanks. ps: My device is still unrooted, I hope it is not the main cause of the error. public DatabaseHelper(Context context) { super(context, DB_NAME, null, 1); this.myContext = context; } public void createDataBase() throws IOException{ boolean dbExist = checkDataBase(); String s = new Boolean(dbExist).toString(); Log.d("dbExist", s ); if(dbExist){ //do nothing - database already exist Log.d("createdatabase","DB exists so do nothing"); }else{ this.getReadableDatabase(); try { copyDataBase(); Log.d("copydatabase","Successful return frm method call!"); } catch (IOException e) { throw new Error("Error copying database"); } } } private boolean checkDataBase(){ File dbFile = new File(DB_PATH + DB_NAME); return dbFile.exists(); } private void copyDataBase() throws IOException{ //Open your local db as the input stream InputStream myInput = null; myInput = myContext.getAssets().open(DB_NAME); Log.d("copydatabase","InputStream successful!"); // Path to the just created empty db String outFileName = DB_PATH + DB_NAME; //Open the empty db as the output stream OutputStream myOutput = new FileOutputStream(outFileName); //transfer bytes from the inputfile to the outputfile byte[] buffer = new byte[1024]; int length; while ((length = myInput.read(buffer))>0){ myOutput.write(buffer, 0, length); } //Close the streams myOutput.flush(); myOutput.close(); myInput.close(); } public void openDataBase() throws SQLException{ //Open the database String myPath = DB_PATH + DB_NAME; myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY); } /* @Override public synchronized void close() { if(myDataBase != null) myDataBase.close(); super.close(); }*/ public void close() { // NOTE: openHelper must now be a member of CallDataHelper; // you currently have it as a local in your constructor if (myDataBase != null) { myDataBase.close(); } } @Override public void onCreate(SQLiteDatabase db) { } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { } }

    Read the article

  • C++ question on file formats and od

    - by user231536
    I have the following simple code: ofstream output("test"); output << 'a'; When I do an octal dump of the file, I get this: 0000000 000141 0000001 I can see that 000141 (in base 8) is 8 bits wide and 0000001 is probably EOF. What is the first byte of all 0's and why is it there? I know it is null is ascii but what is its purpose?

    Read the article

  • How to do a non-waiting write on a named pipe (c#) ?

    - by Jelly Amma
    Hello, I'm using .net 3.5 named pipes and my server side is : serverPipeStream = new NamedPipeServerStream("myPipe", PipeDirection.InOut, 1, PipeTransmissionMode.Byte, PipeOptions.Asynchronous); When I write some data with, say, BinaryWriter, the write() call itself doesn't return until the client side has called a read() on its NamedPipeClientStream. How can I make my write() to the named pipe non-blocking ? Thanks in advance for any help.

    Read the article

  • Limited-length string class

    - by wood_brian
    Is there a limited-length string class around? I've searched a little on the net and didn't find anything. I'm interested in a class that limits (possibly at compile time) the length to 255, so marshalling the string's length only requires one byte.

    Read the article

  • How to access remote lan machines through a ipsec / xl2ptd vpn (maybe iptables related)

    - by Simon
    I’m trying to do the setup of a IPSEC / XL2TPD VPN for our office, and I’m having some problems accessing the remote local machines after connecting to the VPN. I can connect, and I can browse Internet sites trough the VPN, but as said, I’m unable to connect or even ping the local ones. My Network setup is something like this: INTERNET eth0 ROUTER / VPN eth2 LAN These are some traceroutes behind the VPN: traceroute to google.com (173.194.78.94), 64 hops max, 52 byte packets 1 192.168.1.80 (192.168.1.80) 74.738 ms 71.476 ms 70.123 ms 2 10.35.192.1 (10.35.192.1) 77.832 ms 77.578 ms 77.865 ms 3 10.47.243.137 (10.47.243.137) 78.837 ms 85.409 ms 76.032 ms 4 10.47.242.129 (10.47.242.129) 78.069 ms 80.054 ms 77.778 ms 5 10.254.4.2 (10.254.4.2) 86.174 ms 10.254.4.6 (10.254.4.6) 85.687 ms 10.254.4.2 (10.254.4.2) 85.664 ms traceroute to 192.168.1.3 (192.168.1.3), 64 hops max, 52 byte packets 1 * * * 2 *traceroute: sendto: No route to host traceroute: wrote 192.168.1.3 52 chars, ret=-1 *traceroute: sendto: Host is down traceroute: wrote 192.168.1.3 52 chars, ret=-1 * traceroute: sendto: Host is down 3 traceroute: wrote 192.168.1.3 52 chars, ret=-1 *traceroute: sendto: Host is down traceroute: wrote 192.168.1.3 52 chars, ret=-1 These are my iptables rules: iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT # allow lan to router traffic iptables -A INPUT -s 192.168.1.0/24 -i eth2 -j ACCEPT # ssh iptables -A INPUT -p tcp --dport ssh -j ACCEPT # vpn iptables -A INPUT -p 50 -j ACCEPT iptables -A INPUT -p ah -j ACCEPT iptables -A INPUT -p udp --dport 500 -j ACCEPT iptables -A INPUT -p udp --dport 4500 -j ACCEPT iptables -A INPUT -p udp --dport 1701 -j ACCEPT # dns iptables -A INPUT -s 192.168.1.0/24 -p tcp --dport 53 -j ACCEPT iptables -A INPUT -s 192.168.1.0/24 -p udp --dport 53 -j ACCEPT iptables -t nat -A POSTROUTING -j MASQUERADE # logging iptables -I INPUT 5 -m limit --limit 1/min -j LOG --log-prefix "iptables denied: " --log-level 7 # block all other traffic iptables -A INPUT -j DROP And here are some firewall log lines: Dec 6 11:11:57 router kernel: [8725820.003323] iptables denied: IN=ppp0 OUT= MAC= SRC=192.168.1.81 DST=192.168.1.3 LEN=60 TOS=0x00 PREC=0x00 TTL=255 ID=62174 PROTO=UDP SPT=61910 DPT=53 LEN=40 Dec 6 11:12:29 router kernel: [8725852.035826] iptables denied: IN=ppp0 OUT= MAC= SRC=192.168.1.81 DST=224.0.0.1 LEN=44 TOS=0x00 PREC=0x00 TTL=1 ID=15344 PROTO=UDP SPT=56329 DPT=8612 LEN=24 Dec 6 11:12:36 router kernel: [8725859.121606] iptables denied: IN=ppp0 OUT= MAC= SRC=192.168.1.81 DST=224.0.0.1 LEN=44 TOS=0x00 PREC=0x00 TTL=1 ID=11767 PROTO=UDP SPT=63962 DPT=8612 LEN=24 Dec 6 11:12:44 router kernel: [8725866.203656] iptables denied: IN=ppp0 OUT= MAC= SRC=192.168.1.81 DST=224.0.0.1 LEN=44 TOS=0x00 PREC=0x00 TTL=1 ID=11679 PROTO=UDP SPT=57101 DPT=8612 LEN=24 Dec 6 11:12:51 router kernel: [8725873.285979] iptables denied: IN=ppp0 OUT= MAC= SRC=192.168.1.81 DST=224.0.0.1 LEN=44 TOS=0x00 PREC=0x00 TTL=1 ID=39165 PROTO=UDP SPT=62625 DPT=8612 LEN=24 I’m pretty sure that the problem should be related with iptables, but after trying a lot of different confs, I was unable to find the right one. Any help will be greetly appreciated ;). Kind regards, Simon. EDIT: This is my route table: default 62.43.193.33.st 0.0.0.0 UG 100 0 0 eth0 62.43.193.32 * 255.255.255.224 U 0 0 0 eth0 192.168.1.0 * 255.255.255.0 U 0 0 0 eth2 192.168.1.81 * 255.255.255.255 UH 0 0 0 ppp0

    Read the article

  • Is this valid JFS partition?

    - by Coolmax
    This is my first question on StackExchange. My teacher gave my his laptop (with Fedora 16 on it) and compact flash card with data. He want to have access to files on card, but he couldn't get access to it. The problem is Linux don't know what type of partion is. I suppose there is JFS: root@debian:~# dmesg |grep sdc [ 9066.908223] sd 3:0:0:1: [sdc] 3940272 512-byte logical blocks: (2.01 GB/1.87 GiB) [ 9066.962307] sd 3:0:0:1: [sdc] Write Protect is off [ 9066.962310] sd 3:0:0:1: [sdc] Mode Sense: 03 00 00 00 [ 9066.962312] sd 3:0:0:1: [sdc] Assuming drive cache: write through [ 9067.028420] sd 3:0:0:1: [sdc] Assuming drive cache: write through [ 9067.028637] sdc: unknown partition table [ 9067.097065] sd 3:0:0:1: [sdc] Assuming drive cache: write through [ 9067.097281] sd 3:0:0:1: [sdc] Attached SCSI removable disk and some of data: root@debian:~# hexdump -Cn 65536 /dev/sdc 00000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00008000 4a 46 53 31 01 00 00 00 48 63 0e 00 00 00 00 00 |JFS1....Hc......| 00008010 00 10 00 00 0c 00 03 00 00 02 00 00 09 00 00 00 |................| 00008020 00 20 00 00 00 09 20 10 02 00 00 00 00 00 00 00 |. .... .........| 00008030 04 00 00 00 26 00 00 00 02 00 00 00 24 00 00 00 |....&.......$...| 00008040 41 03 00 00 16 00 00 00 00 02 00 00 a0 cc 01 00 |A...............| 00008050 37 00 00 00 69 cc 01 00 b6 d8 ac 4b 00 00 00 00 |7...i......K....| 00008060 32 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 |2...............| 00008070 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 00008080 00 00 00 00 00 00 00 00 90 15 e5 5f e3 c4 45 fa |..........._..E.| 00008090 9d 6a 5c b5 4f da 62 1a 00 00 00 00 00 00 00 00 |.j\.O.b.........| 000080a0 00 00 00 00 00 00 00 00 c3 c9 01 00 ed 81 00 00 |................| 000080b0 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 000080c0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * [cut] * 0000f000 4a 46 53 31 01 00 00 00 48 63 0e 00 00 00 00 00 |JFS1....Hc......| 0000f010 00 10 00 00 0c 00 03 00 00 02 00 00 09 00 00 00 |................| 0000f020 00 20 00 00 00 09 20 10 00 00 00 00 00 00 00 00 |. .... .........| 0000f030 04 00 00 00 26 00 00 00 02 00 00 00 24 00 00 00 |....&.......$...| 0000f040 41 03 00 00 16 00 00 00 00 02 00 00 a0 cc 01 00 |A...............| 0000f050 37 00 00 00 69 cc 01 00 b6 d8 ac 4b 00 00 00 00 |7...i......K....| 0000f060 32 00 00 00 02 00 00 00 00 00 00 00 00 00 00 00 |2...............| 0000f070 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 0000f080 00 00 00 00 00 00 00 00 90 15 e5 5f e3 c4 45 fa |..........._..E.| 0000f090 9d 6a 5c b5 4f da 62 1a 00 00 00 00 00 00 00 00 |.j\.O.b.........| 0000f0a0 00 00 00 00 00 00 00 00 c3 c9 01 00 ed 81 00 00 |................| 0000f0b0 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 0000f0c0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00010000 I'm total newbie to filesystems. I googled and found that JFS superblock may starts on 0x8000 offset. But what next? How to mount this card? If there would be normal partition table I would expect 55 AA on 510th and 511th byte, but first 8000 bytes are clear. Any help would be greatly appreciated. And sorry for my bad english :) Kind regards.

    Read the article

  • An Xml Serializable PropertyBag Dictionary Class for .NET

    - by Rick Strahl
    I don't know about you but I frequently need property bags in my applications to store and possibly cache arbitrary data. Dictionary<T,V> works well for this although I always seem to be hunting for a more specific generic type that provides a string key based dictionary. There's string dictionary, but it only works with strings. There's Hashset<T> but it uses the actual values as keys. In most key value pair situations for me string is key value to work off. Dictionary<T,V> works well enough, but there are some issues with serialization of dictionaries in .NET. The .NET framework doesn't do well serializing IDictionary objects out of the box. The XmlSerializer doesn't support serialization of IDictionary via it's default serialization, and while the DataContractSerializer does support IDictionary serialization it produces some pretty atrocious XML. What doesn't work? First off Dictionary serialization with the Xml Serializer doesn't work so the following fails: [TestMethod] public void DictionaryXmlSerializerTest() { var bag = new Dictionary<string, object>(); bag.Add("key", "Value"); bag.Add("Key2", 100.10M); bag.Add("Key3", Guid.NewGuid()); bag.Add("Key4", DateTime.Now); bag.Add("Key5", true); bag.Add("Key7", new byte[3] { 42, 45, 66 }); TestContext.WriteLine(this.ToXml(bag)); } public string ToXml(object obj) { if (obj == null) return null; StringWriter sw = new StringWriter(); XmlSerializer ser = new XmlSerializer(obj.GetType()); ser.Serialize(sw, obj); return sw.ToString(); } The error you get with this is: System.NotSupportedException: The type System.Collections.Generic.Dictionary`2[[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.Object, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] is not supported because it implements IDictionary. Got it! BTW, the same is true with binary serialization. Running the same code above against the DataContractSerializer does work: [TestMethod] public void DictionaryDataContextSerializerTest() { var bag = new Dictionary<string, object>(); bag.Add("key", "Value"); bag.Add("Key2", 100.10M); bag.Add("Key3", Guid.NewGuid()); bag.Add("Key4", DateTime.Now); bag.Add("Key5", true); bag.Add("Key7", new byte[3] { 42, 45, 66 }); TestContext.WriteLine(this.ToXmlDcs(bag)); } public string ToXmlDcs(object value, bool throwExceptions = false) { var ser = new DataContractSerializer(value.GetType(), null, int.MaxValue, true, false, null); MemoryStream ms = new MemoryStream(); ser.WriteObject(ms, value); return Encoding.UTF8.GetString(ms.ToArray(), 0, (int)ms.Length); } This DOES work but produces some pretty heinous XML (formatted with line breaks and indentation here): <ArrayOfKeyValueOfstringanyType xmlns="http://schemas.microsoft.com/2003/10/Serialization/Arrays" xmlns:i="http://www.w3.org/2001/XMLSchema-instance"> <KeyValueOfstringanyType> <Key>key</Key> <Value i:type="a:string" xmlns:a="http://www.w3.org/2001/XMLSchema">Value</Value> </KeyValueOfstringanyType> <KeyValueOfstringanyType> <Key>Key2</Key> <Value i:type="a:decimal" xmlns:a="http://www.w3.org/2001/XMLSchema">100.10</Value> </KeyValueOfstringanyType> <KeyValueOfstringanyType> <Key>Key3</Key> <Value i:type="a:guid" xmlns:a="http://schemas.microsoft.com/2003/10/Serialization/">2cd46d2a-a636-4af4-979b-e834d39b6d37</Value> </KeyValueOfstringanyType> <KeyValueOfstringanyType> <Key>Key4</Key> <Value i:type="a:dateTime" xmlns:a="http://www.w3.org/2001/XMLSchema">2011-09-19T17:17:05.4406999-07:00</Value> </KeyValueOfstringanyType> <KeyValueOfstringanyType> <Key>Key5</Key> <Value i:type="a:boolean" xmlns:a="http://www.w3.org/2001/XMLSchema">true</Value> </KeyValueOfstringanyType> <KeyValueOfstringanyType> <Key>Key7</Key> <Value i:type="a:base64Binary" xmlns:a="http://www.w3.org/2001/XMLSchema">Ki1C</Value> </KeyValueOfstringanyType> </ArrayOfKeyValueOfstringanyType> Ouch! That seriously hurts the eye! :-) Worse though it's extremely verbose with all those repetitive namespace declarations. It's good to know that it works in a pinch, but for a human readable/editable solution or something lightweight to store in a database it's not quite ideal. Why should I care? As a little background, in one of my applications I have a need for a flexible property bag that is used on a free form database field on an otherwise static entity. Basically what I have is a standard database record to which arbitrary properties can be added in an XML based string field. I intend to expose those arbitrary properties as a collection from field data stored in XML. The concept is pretty simple: When loading write the data to the collection, when the data is saved serialize the data into an XML string and store it into the database. When reading the data pick up the XML and if the collection on the entity is accessed automatically deserialize the XML into the Dictionary. (I'll talk more about this in another post). While the DataContext Serializer would work, it's verbosity is problematic both for size of the generated XML strings and the fact that users can manually edit this XML based property data in an advanced mode. A clean(er) layout certainly would be preferable and more user friendly. Custom XMLSerialization with a PropertyBag Class So… after a bunch of experimentation with different serialization formats I decided to create a custom PropertyBag class that provides for a serializable Dictionary. It's basically a custom Dictionary<TType,TValue> implementation with the keys always set as string keys. The result are PropertyBag<TValue> and PropertyBag (which defaults to the object type for values). The PropertyBag<TType> and PropertyBag classes provide these features: Subclassed from Dictionary<T,V> Implements IXmlSerializable with a cleanish XML format ToXml() and FromXml() methods to export and import to and from XML strings Static CreateFromXml() method to create an instance It's simple enough as it's merely a Dictionary<string,object> subclass but that supports serialization to a - what I think at least - cleaner XML format. The class is super simple to use: [TestMethod] public void PropertyBagTwoWayObjectSerializationTest() { var bag = new PropertyBag(); bag.Add("key", "Value"); bag.Add("Key2", 100.10M); bag.Add("Key3", Guid.NewGuid()); bag.Add("Key4", DateTime.Now); bag.Add("Key5", true); bag.Add("Key7", new byte[3] { 42,45,66 } ); bag.Add("Key8", null); bag.Add("Key9", new ComplexObject() { Name = "Rick", Entered = DateTime.Now, Count = 10 }); string xml = bag.ToXml(); TestContext.WriteLine(bag.ToXml()); bag.Clear(); bag.FromXml(xml); Assert.IsTrue(bag["key"] as string == "Value"); Assert.IsInstanceOfType( bag["Key3"], typeof(Guid)); Assert.IsNull(bag["Key8"]); //Assert.IsNull(bag["Key10"]); Assert.IsInstanceOfType(bag["Key9"], typeof(ComplexObject)); } This uses the PropertyBag class which uses a PropertyBag<string,object> - which means it returns untyped values of type object. I suspect for me this will be the most common scenario as I'd want to store arbitrary values in the PropertyBag rather than one specific type. The same code with a strongly typed PropertyBag<decimal> looks like this: [TestMethod] public void PropertyBagTwoWayValueTypeSerializationTest() { var bag = new PropertyBag<decimal>(); bag.Add("key", 10M); bag.Add("Key1", 100.10M); bag.Add("Key2", 200.10M); bag.Add("Key3", 300.10M); string xml = bag.ToXml(); TestContext.WriteLine(bag.ToXml()); bag.Clear(); bag.FromXml(xml); Assert.IsTrue(bag.Get("Key1") == 100.10M); Assert.IsTrue(bag.Get("Key3") == 300.10M); } and produces typed results of type decimal. The types can be either value or reference types the combination of which actually proved to be a little more tricky than anticipated due to null and specific string value checks required - getting the generic typing right required use of default(T) and Convert.ChangeType() to trick the compiler into playing nice. Of course the whole raison d'etre for this class is the XML serialization. You can see in the code above that we're doing a .ToXml() and .FromXml() to serialize to and from string. The XML produced for the first example looks like this: <?xml version="1.0" encoding="utf-8"?> <properties> <item> <key>key</key> <value>Value</value> </item> <item> <key>Key2</key> <value type="decimal">100.10</value> </item> <item> <key>Key3</key> <value type="___System.Guid"> <guid>f7a92032-0c6d-4e9d-9950-b15ff7cd207d</guid> </value> </item> <item> <key>Key4</key> <value type="datetime">2011-09-26T17:45:58.5789578-10:00</value> </item> <item> <key>Key5</key> <value type="boolean">true</value> </item> <item> <key>Key7</key> <value type="base64Binary">Ki1C</value> </item> <item> <key>Key8</key> <value type="nil" /> </item> <item> <key>Key9</key> <value type="___Westwind.Tools.Tests.PropertyBagTest+ComplexObject"> <ComplexObject> <Name>Rick</Name> <Entered>2011-09-26T17:45:58.5789578-10:00</Entered> <Count>10</Count> </ComplexObject> </value> </item> </properties>   The format is a bit cleaner than the DataContractSerializer. Each item is serialized into <key> <value> pairs. If the value is a string no type information is written. Since string tends to be the most common type this saves space and serialization processing. All other types are attributed. Simple types are mapped to XML types so things like decimal, datetime, boolean and base64Binary are encoded using their Xml type values. All other types are embedded with a hokey format that describes the .NET type preceded by a three underscores and then are encoded using the XmlSerializer. You can see this best above in the ComplexObject encoding. For custom types this isn't pretty either, but it's more concise than the DCS and it works as long as you're serializing back and forth between .NET clients at least. The XML generated from the second example that uses PropertyBag<decimal> looks like this: <?xml version="1.0" encoding="utf-8"?> <properties> <item> <key>key</key> <value type="decimal">10</value> </item> <item> <key>Key1</key> <value type="decimal">100.10</value> </item> <item> <key>Key2</key> <value type="decimal">200.10</value> </item> <item> <key>Key3</key> <value type="decimal">300.10</value> </item> </properties>   How does it work As I mentioned there's nothing fancy about this solution - it's little more than a subclass of Dictionary<T,V> that implements custom Xml Serialization and a couple of helper methods that facilitate getting the XML in and out of the class more easily. But it's proven very handy for a number of projects for me where dynamic data storage is required. Here's the code: /// <summary> /// Creates a serializable string/object dictionary that is XML serializable /// Encodes keys as element names and values as simple values with a type /// attribute that contains an XML type name. Complex names encode the type /// name with type='___namespace.classname' format followed by a standard xml /// serialized format. The latter serialization can be slow so it's not recommended /// to pass complex types if performance is critical. /// </summary> [XmlRoot("properties")] public class PropertyBag : PropertyBag<object> { /// <summary> /// Creates an instance of a propertybag from an Xml string /// </summary> /// <param name="xml">Serialize</param> /// <returns></returns> public static PropertyBag CreateFromXml(string xml) { var bag = new PropertyBag(); bag.FromXml(xml); return bag; } } /// <summary> /// Creates a serializable string for generic types that is XML serializable. /// /// Encodes keys as element names and values as simple values with a type /// attribute that contains an XML type name. Complex names encode the type /// name with type='___namespace.classname' format followed by a standard xml /// serialized format. The latter serialization can be slow so it's not recommended /// to pass complex types if performance is critical. /// </summary> /// <typeparam name="TValue">Must be a reference type. For value types use type object</typeparam> [XmlRoot("properties")] public class PropertyBag<TValue> : Dictionary<string, TValue>, IXmlSerializable { /// <summary> /// Not implemented - this means no schema information is passed /// so this won't work with ASMX/WCF services. /// </summary> /// <returns></returns> public System.Xml.Schema.XmlSchema GetSchema() { return null; } /// <summary> /// Serializes the dictionary to XML. Keys are /// serialized to element names and values as /// element values. An xml type attribute is embedded /// for each serialized element - a .NET type /// element is embedded for each complex type and /// prefixed with three underscores. /// </summary> /// <param name="writer"></param> public void WriteXml(System.Xml.XmlWriter writer) { foreach (string key in this.Keys) { TValue value = this[key]; Type type = null; if (value != null) type = value.GetType(); writer.WriteStartElement("item"); writer.WriteStartElement("key"); writer.WriteString(key as string); writer.WriteEndElement(); writer.WriteStartElement("value"); string xmlType = XmlUtils.MapTypeToXmlType(type); bool isCustom = false; // Type information attribute if not string if (value == null) { writer.WriteAttributeString("type", "nil"); } else if (!string.IsNullOrEmpty(xmlType)) { if (xmlType != "string") { writer.WriteStartAttribute("type"); writer.WriteString(xmlType); writer.WriteEndAttribute(); } } else { isCustom = true; xmlType = "___" + value.GetType().FullName; writer.WriteStartAttribute("type"); writer.WriteString(xmlType); writer.WriteEndAttribute(); } // Actual deserialization if (!isCustom) { if (value != null) writer.WriteValue(value); } else { XmlSerializer ser = new XmlSerializer(value.GetType()); ser.Serialize(writer, value); } writer.WriteEndElement(); // value writer.WriteEndElement(); // item } } /// <summary> /// Reads the custom serialized format /// </summary> /// <param name="reader"></param> public void ReadXml(System.Xml.XmlReader reader) { this.Clear(); while (reader.Read()) { if (reader.NodeType == XmlNodeType.Element && reader.Name == "key") { string xmlType = null; string name = reader.ReadElementContentAsString(); // item element reader.ReadToNextSibling("value"); if (reader.MoveToNextAttribute()) xmlType = reader.Value; reader.MoveToContent(); TValue value; if (xmlType == "nil") value = default(TValue); // null else if (string.IsNullOrEmpty(xmlType)) { // value is a string or object and we can assign TValue to value string strval = reader.ReadElementContentAsString(); value = (TValue) Convert.ChangeType(strval, typeof(TValue)); } else if (xmlType.StartsWith("___")) { while (reader.Read() && reader.NodeType != XmlNodeType.Element) { } Type type = ReflectionUtils.GetTypeFromName(xmlType.Substring(3)); //value = reader.ReadElementContentAs(type,null); XmlSerializer ser = new XmlSerializer(type); value = (TValue)ser.Deserialize(reader); } else value = (TValue)reader.ReadElementContentAs(XmlUtils.MapXmlTypeToType(xmlType), null); this.Add(name, value); } } } /// <summary> /// Serializes this dictionary to an XML string /// </summary> /// <returns>XML String or Null if it fails</returns> public string ToXml() { string xml = null; SerializationUtils.SerializeObject(this, out xml); return xml; } /// <summary> /// Deserializes from an XML string /// </summary> /// <param name="xml"></param> /// <returns>true or false</returns> public bool FromXml(string xml) { this.Clear(); // if xml string is empty we return an empty dictionary if (string.IsNullOrEmpty(xml)) return true; var result = SerializationUtils.DeSerializeObject(xml, this.GetType()) as PropertyBag<TValue>; if (result != null) { foreach (var item in result) { this.Add(item.Key, item.Value); } } else // null is a failure return false; return true; } /// <summary> /// Creates an instance of a propertybag from an Xml string /// </summary> /// <param name="xml"></param> /// <returns></returns> public static PropertyBag<TValue> CreateFromXml(string xml) { var bag = new PropertyBag<TValue>(); bag.FromXml(xml); return bag; } } } The code uses a couple of small helper classes SerializationUtils and XmlUtils for mapping Xml types to and from .NET, both of which are from the WestWind,Utilities project (which is the same project where PropertyBag lives) from the West Wind Web Toolkit. The code implements ReadXml and WriteXml for the IXmlSerializable implementation using old school XmlReaders and XmlWriters (because it's pretty simple stuff - no need for XLinq here). Then there are two helper methods .ToXml() and .FromXml() that basically allow your code to easily convert between XML and a PropertyBag object. In my code that's what I use to actually to persist to and from the entity XML property during .Load() and .Save() operations. It's sweet to be able to have a string key dictionary and then be able to turn around with 1 line of code to persist the whole thing to XML and back. Hopefully some of you will find this class as useful as I've found it. It's a simple solution to a common requirement in my applications and I've used the hell out of it in the  short time since I created it. Resources You can find the complete code for the two classes plus the helpers in the Subversion repository for Westwind.Utilities. You can grab the source files from there or download the whole project. You can also grab the full Westwind.Utilities assembly from NuGet and add it to your project if that's easier for you. PropertyBag Source Code SerializationUtils and XmlUtils Westwind.Utilities Assembly on NuGet (add from Visual Studio) © Rick Strahl, West Wind Technologies, 2005-2011Posted in .NET  CSharp   Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 79 80 81 82 83 84 85 86 87 88 89 90  | Next Page >