I currently develop an application which contains a custom ListView. I developed a custom array adapter. I think my app crashes here:

ListView DirectoryView = (ListView) findViewById(R.id.fileListView);

So i think the error is in the activity_main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

<ListView
    android:id="@+id/fileListView"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_weight="1" >
</ListView>

Here is my LogCat:

09-09 11:19:21.254: E/Trace(1152): error opening trace file: No such file or directory (2)
09-09 11:19:21.484: D/AndroidRuntime(1152): Shutting down VM
09-09 11:19:21.484: W/dalvikvm(1152): threadid=1: thread exiting with uncaught exception (group=0x40a13300)
09-09 11:19:21.504: E/AndroidRuntime(1152): FATAL EXCEPTION: main
09-09 11:19:21.504: E/AndroidRuntime(1152): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.teamdroid.explorer/com.teamdroid.explorer.MainActivity}: java.lang.NullPointerException
09-09 11:19:21.504: E/AndroidRuntime(1152):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2059)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at android.app.ActivityThread.access$600(ActivityThread.java:130)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at android.os.Handler.dispatchMessage(Handler.java:99)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at android.os.Looper.loop(Looper.java:137)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at android.app.ActivityThread.main(ActivityThread.java:4745)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at java.lang.reflect.Method.invokeNative(Native Method)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at java.lang.reflect.Method.invoke(Method.java:511)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at dalvik.system.NativeStart.main(Native Method)
09-09 11:19:21.504: E/AndroidRuntime(1152): Caused by: java.lang.NullPointerException
09-09 11:19:21.504: E/AndroidRuntime(1152):     at android.app.Activity.findViewById(Activity.java:1825)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at com.teamdroid.explorer.listDirectory.getDirectory(listDirectory.java:20)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at com.teamdroid.explorer.MainActivity.onCreate(MainActivity.java:33)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at android.app.Activity.performCreate(Activity.java:5008)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
09-09 11:19:21.504: E/AndroidRuntime(1152):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
09-09 11:19:21.504: E/AndroidRuntime(1152):     ... 11 more

Please can you help me. I am searching this error for 2 day. thanks!