Android Question Bitmap.InitializeMutable(width, height) Unknown member ?

[MitchBu]

I am trying to initialize a Mutable Bitmap so I can draw onto it with a canvas and then save to disk without drawing onto the activity, but I get
Unknown member: initializemutable

Here is what I did :

bitmap2.InitializeMutable(800,600)

I read several times https://www.b4x.com/android/help/drawing.html#bitmapdrawable_initialize without finding any way to apply this :

InitializeMutable (Width As Int, Height As Int)
Creates a new mutable bitmap with the specified dimensions. You can use a Canvas object to draw on this bitmap.

 

[DonManfred]

What is bitmap2?

 

[MitchBu]

Precisely my question is how does such an object can be created. Apparently neither bitmap which is read only nor bitmapDrawable seem to be OK.

This is the code I tried and which triggers the exception :

Private bitmap2 As BitmapDrawable
bitmap2.InitializeMutable(800,600)

It is my hope that Erel, or somebody else, will post the exact code to use.

I found two related questions but none gives more information than what I already have

https://www.b4x.com/android/forum/threads/bitmap-initializemutable-does-not-work.54795/
and https://www.b4x.com/android/forum/threads/initializemutable.27618/

 

[MitchBu]

If I declare as bitmap, it compiles, but afterward I get this :

** Service (starter) Create **
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
Error occurred on line: 39 (Main)
java.lang.IllegalArgumentException: method anywheresoftware.b4a.objects.drawable.CanvasWrapper.Initialize argument 1 has type android.view.View, got android.graphics.Bitmap
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at anywheresoftware.b4a.shell.Shell.runVoidMethod(Shell.java:753)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:343)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:247)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:134)
at b4a.canvas.main.afterFirstLayout(main.java:102)
at b4a.canvas.main.access$000(main.java:17)
at b4a.canvas.main$WaitForLayout.run(main.java:80)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:6134)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)
** Activity (main) Resume **

 

[Erel]

You need to use Canvas.Initialize2 to draw over a mutable bitmap. Canvas.Initialize expects a view.
https://www.b4x.com/android/help/drawing.html#canvas_initialize2

 

[MitchBu]

It works !

   Private bitmap2 As Bitmap
    bitmap2.InitializeMutable(800,600)
    cvs.Initialize2(bitmap2)
    cvs.DrawColor(Colors.Green)
    Dim Out As OutputStream
    Out = File.OpenOutput(File.DirRootExternal, "reTest.png", False)
    cvs.Bitmap.WriteToStream(Out, 100, "PNG")
    Out.Close

Thank you so much for the friendly hands