Image-view not showing in xml defined Frame-Layout on Android application

Question

I have a frame-layout defined in xml a follows:

//pseudo code
<FrameLayout
android:height = "match_parent" // same for width
android:background="@android:color/white"
padding = "20dp"
id = "polygraph"
layout_gravity="center"/>

I access this xml view via code as such:

LayoutInflater inflater = this.getLayoutInflater();
frameInflate = (FrameLayout) inflater.inflate(R.layout.mframe,null);
frar = (FrameLayout)frameInflate.findViewById(R.id.polygraph);

I create the following image-view dynamically but somehow it doesn't show inside this frame-layout which is one of many views inside another frame-layout that holds all the views of my User-Interface

view1 = new ImageView(this);
view1.setAdjustViewBounds(false);
matrix = new Matrix();
view1.setScaleType(ImageView.ScaleType.Matrix);//I have tried: ScaleType.Center it did not work at all
view1.setImageMatrix(matrix);
view1.setBackgroundColor(Color.GRAY);
params11= new FrameLayout.LayoutParams(200,300,Gravity.CENTER);
view1.setLayoutParams(params11);
DummyDraw drawD = new DummyDraw(this);
view1.setImageDrawable(drawD);

frar.addView(view1);

//somewhere down on onWindowsFocusChange()
frar.invalidate();  //try to invalidate to see if it will show the imageview

No image-view shows at all. I have tried different ways, such as:

frar.addView(view1,params11); //did not work
//instead of view1.setImageDrawable
view1.setBackground(drawD); //nothing
view1.setImageResource(R.drawable.somerandomdrawable);//nothing

I have no idea why this view isn't showing. Could it be the drawable "drawD"? If it is this drawable, then why isn't showing at least the background color "gray" which I set in the code? I have tried to get rid of the ScaleType.Matrix to something else, such as ScaleType.Center, but nothing seems to work.

Any advice or suggestions will be appreciated

thanks

Answer 1

I had ran into the same problem a few months ago. But I did forget how to handle it. LayoutInflater wasn't needed to solve the problem. Seems like I can't do this call inside onCreate() "(FrameLayout)findViewById(R.id.polygraph)" and then try to add my programmatically created image-view to my xml layout element. It gave me a null pointer exception all the time.

Moving both calls way after the layout pass, such as on onStart() or onWindowsFocusChanged() works well. The image-view is added to the xml frame-layout, which in the end it works well for my app, since I had the intentions of adding the image-view well beyond the layout pass.