Question

任何人都可以帮助我以下 -
1.它不应该粘在触点上，它应该从任何一点开始拖动 2. DragShadowBuilder视图应该在没有放入正确目标时进行动画显示。

Answer 1

我通过创建自定义View.DragShadowBuilder 类来实现这一目标。

相同的代码是：

public class CustomDragShadowBuilder extends View.DragShadowBuilder {
View v;
public CustomDragShadowBuilder(View v) {
    super(v);
    this.v=v;
}
@Override
public void onDrawShadow(Canvas canvas) {
    super.onDrawShadow(canvas);

    /*Modify canvas if you want to show some custom view that you want
      to animate, that you can check by putting a condition passed over
      constructor. Here I'm taking the same view*/ 

    canvas.drawBitmap(getBitmapFromView(v), 0, 0, null);
}
@Override
public void onProvideShadowMetrics(Point shadowSize, Point touchPoint) {
/*Modify x,y of shadowSize to change the shadow view 
   according to your requirements. Here I'm taking the same view width and height*/ 
    shadowSize.set(v.getWidth(),v.getHeight());
/*Modify x,y of touchPoint to change the touch for the view 
 as per your needs. You may pass your x,y position of finger 
 to achieve your results. Here I'm taking the lower end point of view*/
    touchPoint.set(v.getWidth(), v.getHeight());
  }
}

用于将视图转换为位图，取自here：

private Bitmap getBitmapFromView(View view) {
    //Define a bitmap with the same size as the view
    Bitmap returnedBitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(),Bitmap.Config.ARGB_8888);
    //Bind a canvas to it
    Canvas canvas = new Canvas(returnedBitmap);
    //Get the view's background
    Drawable bgDrawable =view.getBackground();
    if (bgDrawable!=null) 
        //has background drawable, then draw it on the canvas
        bgDrawable.draw(canvas);
    else 
        //does not have background drawable, then draw white background on the canvas
        canvas.drawColor(Color.WHITE);
    // draw the view on the canvas
    view.draw(canvas);
    //return the bitmap
    return returnedBitmap;
}

虽然这是一个老问题，但对于想要使用自定义DragShadowBuilder的其他人来说可能会有所帮助。

代码中的注释是自解释的，有关详细信息，请通知我。希望它有所帮助。

Android DragShadowBuilder坚持触摸点的中心

1 个答案: