onTouch 后来自 ImageView 的位图

Question

我有一个 imageview，在我在这个 imageview 上添加图像（标记）之后。 最后，我想创建一个位图，包括新的标记。 但是如果我尝试从相对布局创建位图，我会创建一个没有新标记的图像！为什么？

    imageview= (ImageView)findViewById(R.id.image);

    //insert a marker on my imageview
    final RelativeLayout rr = (RelativeLayout) findViewById(R.id.relative);
    rr.setOnTouchListener(new OnTouchListener() {

    public boolean onTouch(View v, MotionEvent event) {
          if (event.getAction() == MotionEvent.ACTION_DOWN){
              int x = (int) event.getX() ;
              int y = (int) event.getY();
              RelativeLayout.LayoutParams lp =new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);; //Assuming you use a RelativeLayout
              ImageView iv=new ImageView(getApplicationContext());
              lp.setMargins(x,y,0,0);
              iv.setLayoutParams(lp);
              iv.setImageDrawable(getResources().getDrawable(R.drawable.marker));
              ((ViewGroup)v).addView(iv);

    //create a bitmap from relative layout but the new bitmap is without marker
    Bitmap b1 = Bitmap.createBitmap(rr.getWidth(), rr.getHeight(), Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(b1);
    ((ViewGroup)v).draw(c);

          }
          return false;
    }

Answer 1

这是因为动态添加标记到布局中，添加动态视图有一些延迟。这就是创建没有标记的位图的原因。在第二次触摸时，将创建单个标记位图。解决方案是延迟保存位图。

解决方案在这里：

private Handler handler = new Handler();      //handler object in global

rr.setOnTouchListener(new OnTouchListener() {

public boolean onTouch(View v, MotionEvent event) {
      if (event.getAction() == MotionEvent.ACTION_DOWN){
          int x = (int) event.getX() ;
          int y = (int) event.getY();
          RelativeLayout.LayoutParams lp =new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);; //Assuming you use a RelativeLayout
          ImageView iv=new ImageView(getApplicationContext());
          lp.setMargins(x,y,0,0);
          iv.setLayoutParams(lp);
          iv.setImageDrawable(getResources().getDrawable(R.drawable.marker));
          ((ViewGroup)v).addView(iv);

          //run handler after 1000 milli seconds i.e 1 sec
          handler.postDelayed(runnable, 1000);
      }
      return false;
}

private Runnable runnable = new Runnable() {

    @Override
    public void run() {
        //wrote your block of code here
        //create a bitmap from relative layout but the new bitmap is without marker
        Bitmap b1 = Bitmap.createBitmap(rr.getWidth(), rr.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas c = new Canvas(b1);
       ((ViewGroup)v).draw(c);
    }
};

看这里How to Save Bitmap as image in SD card