I have created a FileDialog activity in Mono for Android. However, it seems to

Question

0

Asked: June 7, 20262026-06-07T04:57:33+00:00 2026-06-07T04:57:33+00:00

I have created a FileDialog activity in Mono for Android. However, it seems to

0

I have created a FileDialog activity in Mono for Android. However, it seems to me that there is an issue with some MonoObject to JavaObject casting when using ListView simpleadapter.
After I have left onCreate the VM crashes with the following stacktrace:

07-05 15:04:46.493 D/FileDialogActivity( 3430): Left OnCreate
07-05 15:04:46.503 D/AndroidRuntime( 3430): Shutting down VM
07-05 15:04:46.503 W/dalvikvm( 3430): threadid=1: thread exiting with uncaught exception (group=0xb4127180)
07-05 15:04:46.523 D/dalvikvm( 3430): GC_CONCURRENT freed 115K, 3% free 9634K/9863K, paused 0ms+2ms
07-05 15:04:46.523 E/AndroidRuntime( 3430): FATAL EXCEPTION: main
07-05 15:04:46.523 E/AndroidRuntime( 3430): java.lang.ClassCastException: mono.android.runtime.JavaObject cannot be cast to java.util.Map
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.SimpleAdapter.bindView(SimpleAdapter.java:147)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.SimpleAdapter.createViewFromResource(SimpleAdapter.java:126)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.SimpleAdapter.getView(SimpleAdapter.java:114)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.AbsListView.obtainView(AbsListView.java:2033)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.ListView.makeAndAddView(ListView.java:1772)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.ListView.fillDown(ListView.java:672)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.ListView.fillFromTop(ListView.java:732)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.ListView.layoutChildren(ListView.java:1625)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.AbsListView.onLayout(AbsListView.java:1863)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.View.layout(View.java:11278)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewGroup.layout(ViewGroup.java:4224)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1628)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1486)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.LinearLayout.onLayout(LinearLayout.java:1399)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.View.layout(View.java:11278)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewGroup.layout(ViewGroup.java:4224)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.RelativeLayout.onLayout(RelativeLayout.java:925)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.View.layout(View.java:11278)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewGroup.layout(ViewGroup.java:4224)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.FrameLayout.onLayout(FrameLayout.java:431)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.View.layout(View.java:11278)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewGroup.layout(ViewGroup.java:4224)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1628)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1486)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.LinearLayout.onLayout(LinearLayout.java:1399)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.View.layout(View.java:11278)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewGroup.layout(ViewGroup.java:4224)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.FrameLayout.onLayout(FrameLayout.java:431)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.View.layout(View.java:11278)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewGroup.layout(ViewGroup.java:4224)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.FrameLayout.onLayout(FrameLayout.java:431)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.View.layout(View.java:11278)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewGroup.layout(ViewGroup.java:4224)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1628)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1486)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.LinearLayout.onLayout(LinearLayout.java:1399)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.View.layout(View.java:11278)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewGroup.layout(ViewGroup.java:4224)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.FrameLayout.onLayout(FrameLayout.java:431)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.View.layout(View.java:11278)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewGroup.layout(ViewGroup.java:4224)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.FrameLayout.onLayout(FrameLayout.java:431)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.View.layout(View.java:11278)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewGroup.layout(ViewGroup.java:4224)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1628)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1486)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.LinearLayout.onLayout(LinearLayout.java:1399)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.View.layout(View.java:11278)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewGroup.layout(ViewGroup.java:4224)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.widget.FrameLayout.onLayout(FrameLayout.java:431)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.View.layout(View.java:11278)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewGroup.layout(ViewGroup.java:4224)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1489)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2442)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.os.Handler.dispatchMessage(Handler.java:99)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.os.Looper.loop(Looper.java:137)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at android.app.ActivityThread.main(ActivityThread.java:4424)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at java.lang.reflect.Method.invokeNative(Native Method)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at java.lang.reflect.Method.invoke(Method.java:511)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
07-05 15:04:46.523 E/AndroidRuntime( 3430):     at dalvik.system.NativeStart.main(Native Method)

Some Code:

IList<IDictionary<string, object>> mData = new List<IDictionary<string, object>>();
AddFiles(files, mData); // Which just new Dictionary with filedata and icon from a list of files.
SimpleAdapter fileAdapter = new SimpleAdapter(this, mData,
            Resource.Layout.FileDialogRow,
            new string[] { FileKey, FileImage },
            new int[] { Resource.Id.fdrowname, Resource.Id.fdrowimage }
        );
ListAdapter = fileAdapter;
Log.Debug("Left OnCreate");

Anyone else have an issue when using SimpleAdapter on Mono for Android? Or have any clues to what happens here??

Report

Leave an answer
Cancel reply

You must login to add an answer.

Need An Account,

1 Answer

Editorial Team · Answer 1 · 2026-06-07T04:57:34+00:00

Editorial Team

2026-06-07T04:57:34+00:00Added an answer on June 7, 2026 at 4:57 am

Instead of using List I think you will need to use JavaList. Like:

var mData = new JavaList<IDictionary<string, object>>();

There is a long explanation it this thread: http://mono-for-android.1047100.n5.nabble.com/SimpleAdapter-break-in-4-2-1-td5709793.html

I you are going to use more complex things in your list I suggest implementing your own Adapter, which is a lot easier to maintain and debug in the end.

0

Reply
Share
Share

- Report

Sign Up

Sign In

Forgot Password

The Archive Base Latest Questions

I have created a FileDialog activity in Mono for Android. However, it seems to

Leave an answerCancel reply

1 Answer

Leave an answer
Cancel reply