c# Counter requires 2 button clicks to update
- by marko.ivanovski.nz
Hi,
I have a problem that has been bugging me all day.
In my code I have the following:
private int rowCount
{
get { return (int)ViewState["rowCount"]; }
set { ViewState["rowCount"] = value; }
}
and a button event
protected void addRow_Click(object sender, EventArgs e)
{
rowCount = rowCount + 1;
}
Then on Page_Load I read that value and create controls accordingly.
I understand the button event fires AFTER the Page_Load fires so the value isn't updated until the next postback. Real nightmare.
Here's the entire code:
protected void Page_Load(object sender, EventArgs e)
{
string xmlValue = ""; //To read a value from a database
if (xmlValue.Length > 0)
{
if (!Page.IsPostBack)
{
DataSet ds = XMLToDataSet(xmlValue);
Table dimensionsTable = DataSetToTable(ds);
tablePanel.Controls.Add(dimensionsTable);
DataTable dt = ds.Tables["Dimensions"];
rowCount = dt.Rows.Count;
colCount = dt.Columns.Count;
}
else
{
tablePanel.Controls.Add(DataSetToTable(DefaultDataSet(rowCount, colCount)));
}
}
else
{
if (!Page.IsPostBack)
{
rowCount = 2;
colCount = 4;
}
tablePanel.Controls.Add(DataSetToTable(DefaultDataSet(rowCount, colCount)));
}
}
protected void submit_Click(object sender, EventArgs e)
{
resultsLabel.Text = Server.HtmlEncode(DataSetToStringXML(TableToDataSet((Table)tablePanel.Controls[0])));
}
protected void addColumn_Click(object sender, EventArgs e)
{
colCount = colCount + 1;
}
protected void addRow_Click(object sender, EventArgs e)
{
rowCount = rowCount + 1;
}
public DataSet TableToDataSet(Table table)
{
DataSet ds = new DataSet();
DataTable dt = new DataTable("Dimensions");
ds.Tables.Add(dt);
//Add headers
for (int i = 0; i < table.Rows[0].Cells.Count; i++)
{
DataColumn col = new DataColumn();
TextBox headerTxtBox = (TextBox)table.Rows[0].Cells[i].Controls[0];
col.ColumnName = headerTxtBox.Text;
col.Caption = headerTxtBox.Text;
dt.Columns.Add(col);
}
for (int i = 0; i < table.Rows.Count; i++)
{
DataRow valueRow = dt.NewRow();
for (int x = 0; x < table.Rows[i].Cells.Count; x++)
{
TextBox valueTextBox = (TextBox)table.Rows[i].Cells[x].Controls[0];
valueRow[x] = valueTextBox.Text;
}
dt.Rows.Add(valueRow);
}
return ds;
}
public Table DataSetToTable(DataSet ds)
{
DataTable dt = ds.Tables["Dimensions"];
Table newTable = new Table();
//Add headers
TableRow headerRow = new TableRow();
for (int i = 0; i < dt.Columns.Count; i++)
{
TableCell headerCell = new TableCell();
TextBox headerTxtBox = new TextBox();
headerTxtBox.ID = "HeadersTxtBox" + i.ToString();
headerTxtBox.Font.Bold = true;
headerTxtBox.Text = dt.Columns[i].ColumnName;
headerCell.Controls.Add(headerTxtBox);
headerRow.Cells.Add(headerCell);
}
newTable.Rows.Add(headerRow);
//Add value rows
for (int i = 0; i < dt.Rows.Count; i++)
{
TableRow valueRow = new TableRow();
for (int x = 0; x < dt.Columns.Count; x++)
{
TableCell valueCell = new TableCell();
TextBox valueTxtBox = new TextBox();
valueTxtBox.ID = "ValueTxtBox" + i.ToString() + i + x + x.ToString();
valueTxtBox.Text = dt.Rows[i][x].ToString();
valueCell.Controls.Add(valueTxtBox);
valueRow.Cells.Add(valueCell);
}
newTable.Rows.Add(valueRow);
}
return newTable;
}
public DataSet DefaultDataSet(int rows, int cols)
{
DataSet ds = new DataSet();
DataTable dt = new DataTable("Dimensions");
ds.Tables.Add(dt);
DataColumn nameCol = new DataColumn();
nameCol.Caption = "Name";
nameCol.ColumnName = "Name";
nameCol.DataType = System.Type.GetType("System.String");
dt.Columns.Add(nameCol);
DataColumn widthCol = new DataColumn();
widthCol.Caption = "Width";
widthCol.ColumnName = "Width";
widthCol.DataType = System.Type.GetType("System.String");
dt.Columns.Add(widthCol);
if (cols > 2)
{
DataColumn heightCol = new DataColumn();
heightCol.Caption = "Height";
heightCol.ColumnName = "Height";
heightCol.DataType = System.Type.GetType("System.String");
dt.Columns.Add(heightCol);
}
if (cols > 3)
{
DataColumn depthCol = new DataColumn();
depthCol.Caption = "Depth";
depthCol.ColumnName = "Depth";
depthCol.DataType = System.Type.GetType("System.String");
dt.Columns.Add(depthCol);
}
if (cols > 4)
{
int newColCount = cols - 4;
for (int i = 0; i < newColCount; i++)
{
DataColumn newCol = new DataColumn();
newCol.Caption = "New " + i.ToString();
newCol.ColumnName = "New " + i.ToString();
newCol.DataType = System.Type.GetType("System.String");
dt.Columns.Add(newCol);
}
}
for (int i = 0; i < rows; i++)
{
DataRow newRow = dt.NewRow();
newRow["Name"] = "Name " + i.ToString();
newRow["Width"] = "Width " + i.ToString();
if (cols > 2)
{
newRow["Height"] = "Height " + i.ToString();
}
if (cols > 3)
{
newRow["Depth"] = "Depth " + i.ToString();
}
dt.Rows.Add(newRow);
}
return ds;
}
public DataSet XMLToDataSet(string xml)
{
StringReader sr = new StringReader(xml);
DataSet ds = new DataSet();
ds.ReadXml(sr);
return ds;
}
public string DataSetToStringXML(DataSet ds)
{
XmlDocument _XMLDoc = new XmlDocument();
_XMLDoc.LoadXml(ds.GetXml());
StringWriter sw = new StringWriter();
XmlTextWriter xw = new XmlTextWriter(sw);
XmlDocument xml = _XMLDoc;
xml.WriteTo(xw);
return sw.ToString();
}
private int rowCount
{
get { return (int)ViewState["rowCount"]; }
set { ViewState["rowCount"] = value; }
}
private int colCount
{
get { return (int)ViewState["colCount"]; }
set { ViewState["colCount"] = value; }
}
Thanks in advance,
Marko
