Converting a View to Bitmap Without Displaying It in Android

Converting a view to Bitmap without displaying it in Android?

there is a way to do this. you have to create a Bitmap and a Canvas and call view.draw(canvas);

here is the code:

public static Bitmap loadBitmapFromView(View v) {
    Bitmap b = Bitmap.createBitmap( v.getLayoutParams().width, v.getLayoutParams().height, Bitmap.Config.ARGB_8888);                
    Canvas c = new Canvas(b);
    v.layout(v.getLeft(), v.getTop(), v.getRight(), v.getBottom());
    v.draw(c);
    return b;
}

if the view wasn't displayed before the size of it will be zero. Its possible to measure it like this:

if (v.getMeasuredHeight() <= 0) {
    v.measure(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    Bitmap b = Bitmap.createBitmap(v.getMeasuredWidth(), v.getMeasuredHeight(), Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(b);
    v.layout(0, 0, v.getMeasuredWidth(), v.getMeasuredHeight());
    v.draw(c);
    return b;
}

EDIT: according to this post, Passing WRAP_CONTENT as value to makeMeasureSpec() doesn't to do any good (although for some view classes it does work), and the recommended method is:

// Either this
int specWidth = MeasureSpec.makeMeasureSpec(parentWidth, MeasureSpec.AT_MOST);
// Or this
int specWidth = MeasureSpec.makeMeasureSpec(0 /* any */, MeasureSpec.UNSPECIFIED);
view.measure(specWidth, specWidth);
int questionWidth = view.getMeasuredWidth();

android converting XML View to Bitmap without showing it

Your cluster.getLayoutParams() is probably null. First, you need to measure the width/height of your inflated view and then assign to it. Do it as below:

private Bitmap createClusterBitmap(int clusterSize) {
    View cluster = LayoutInflater.from(context).inflate(R.layout.map_cluster,
            null);

    TextView clusterSizeText = (TextView) cluster.findViewById(R.id.map_cluster_text);
    clusterSizeText.setText(String.valueOf(clusterSize));

    cluster.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
            MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
    cluster.layout(0, 0, cluster.getMeasuredWidth(),cluster.getMeasuredHeight());

    final Bitmap clusterBitmap = Bitmap.createBitmap(cluster.getMeasuredWidth(),
            cluster.getMeasuredHeight(), Bitmap.Config.ARGB_8888);

    Canvas canvas = new Canvas(clusterBitmap);
    cluster.draw(canvas);

    return clusterBitmap;
}

Android Convert view to BitMap

Hi you can use this method to convert View to Bitmap

private Bitmap createBitmapFromView(Context context, View view) {
        DisplayMetrics displayMetrics = new DisplayMetrics();
        ((Activity) context).getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
        view.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

        view.measure(displayMetrics.widthPixels, displayMetrics.heightPixels);
        view.layout(0, 0, displayMetrics.widthPixels, displayMetrics.heightPixels);
        view.buildDrawingCache();
        Bitmap bitmap = Bitmap.createBitmap(view.getMeasuredWidth(), view.getMeasuredHeight(), Bitmap.Config.ARGB_8888);

        Canvas canvas = new Canvas(bitmap);
        view.draw(canvas);

        return bitmap;
    }

Creating a bitmap of a View that never gets drawn

Thanks to both @Rafael Toledo and @Roman_Donchenko, I figured out the issue. The problem was that my custom view was doing the drawing in the onDraw method which doesn't get called. In my case, I simply needed to perform the drawing done in the onDraw directly to the canvas and then used the bitmap passed to the canvas. My code ended up being:

public Bitmap getBitmapFromCircleView(CircleView v)
{
    Bitmap bitmap = Bitmap.createBitmap(v.getLayoutParams().width, v.getLayoutParams().height, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);
    v.drawToCanvas(canvas); //Method in the custom CircleView class, posted below
    return bitmap;
}

public class CircleView extends View
{
    ... //Constructors

    public Canvas drawToCanvas(Canvas canvas)
    {
        canvas.drawColor(0x00000000);

        if(m_lineWidthPx == 0) //Previously set
            return null;

        int width = getLayoutParams().width;
        int height = getLayoutParams().height;

        float centerX = height / 2.f;
        float centerY = height / 2.f;
        float radius = width / 2.f - (m_lineWidthPx) / 2.f;
        m_paint.setStrokeWidth(m_lineWidthPx); 
        m_paint.setStyle(Paint.Style.STROKE);
        m_paint.setAntiAlias(true);
        canvas.drawCircle(centerX, centerY, radius, m_paint);
        return canvas;
    }

    @Override protected void onDraw(Canvas c)
    {
        ... //Code here remained unchanged
    }
}

How to convert View to Bitmap in android?

Activity Class In this Class I Convert the Layout(View) into Image.

import android.os.Bundle;
import android.app.Activity;
import android.graphics.Bitmap;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageView;
import android.widget.LinearLayout;

public class ImageActivity extends Activity {

    LinearLayout layout=null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_convert);
        layout=(LinearLayout)findViewById(R.id.layout);
        ((ImageView)findViewById(R.id.ImageView01)).setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Bitmap map=ConvertToBitmap(layout);
                Log.v("BitmapObject", map.toString());
            }
        });       
    }

    protected Bitmap ConvertToBitmap(LinearLayout layout) {
        Bitmap map;
        layout.setDrawingCacheEnabled(true);
        layout.buildDrawingCache();
        return map=layout.getDrawingCache();
    }
}

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