「Android」ImageView取得touch點的RGB

 imageView.setOnTouchListener(imgSourceOnTouchListener);



 OnTouchListener imgSourceOnTouchListener

= new OnTouchListener(){



    @Override

    public boolean onTouch(View view, MotionEvent event) {



        float eventX = event.getX();

        float eventY = event.getY();

        float[] eventXY = new float[] {eventX, eventY};

        Matrix invertMatrix = new Matrix();

        ((ImageView)view).getImageMatrix().invert(invertMatrix);

        invertMatrix.mapPoints(eventXY);

        int x = Integer.valueOf((int)eventXY[0]);

        int y = Integer.valueOf((int)eventXY[1]);

        Drawable imgDrawable = ((ImageView)view).getDrawable();

        Bitmap bitmap = ((BitmapDrawable)imgDrawable).getBitmap();


        //Limit x, y range within bitmap

        if(x < 0){

            x = 0;

        }else if(x > bitmap.getWidth()-1){

            x = bitmap.getWidth()-1;

        }



        if(y < 0){

            y = 0;

        }else if(y > bitmap.getHeight()-1){

            y = bitmap.getHeight()-1;

        }

        int touchedRGB = bitmap.getPixel(x, y);

        System.out.println("touched color: " + "#" + 
                     Integer.toHexString(touchedRGB));

        return true;

    }};

比較需要注意的是這一行

Bitmap bitmap = ((BitmapDrawable)imgDrawable).getBitmap(); 如果你的ImageView的圖是設成background，你這一行要改寫成

Bitmap bitmap = ((BitmapDrawable)imgDrawable).getBackground();