Android弹出窗口

1.PopupWindow实现：
private void showPopupWindow(int x, int y, int width, int height) {
TextView textView = new TextView(this);
textView.setText("Hello popupWindow");
textView.setBackgroundColor(Color.CYAN);
PopupWindow popupWindow = new PopupWindow(textView, width, height);
popupWindow.showAtLocation(getWindow().getDecorView(),
Gravity.NO_GRAVITY, x, y);
}
不能在onCreate中，否则会报错，需要View渲染完成后调用

2.Dialog实现
    public class MyActivity extends Activity {
    
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.main);
            //在指定位置显示对话框
    showDialog(100, 100, 200, 200);
        }
        
        @Override
        protected Dialog onCreateDialog(int id, Bundle args) {
            return new AlertDialog.Builder(this)
                .setTitle("Hello Dialog!")
                .setMessage("Hello Dialog")
                .create();
        }
        
        @Override
        protected void onPrepareDialog(int id, Dialog dialog, Bundle args) {
            switch (id) {
            case 1: {
    //设置对话框的属性
                Window window = dialog.getWindow();
                WindowManager.LayoutParams lp = window.getAttributes();
                lp.x = args.getInt("x");
                lp.y = args.getInt("y");
                lp.width = args.getInt("width");
                lp.height = args.getInt("height");
                
                lp.flags &= ~WindowManager.LayoutParams.FLAG_DIM_BEHIND;
    
                dialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.argb(0, 0, 0, 0)));
            }
                break;
    
            default:
                break;
            }
    
            super.onPrepareDialog(id, dialog, args);
        }
    
        private void showDialog(int x, int y, int width, int height) {
            Bundle bundle = new Bundle();
            bundle.putInt("x", x);
            bundle.putInt("y", y);
            bundle.putInt("width", width);
            bundle.putInt("height", height);
            
            showDialog(1, bundle);
        }
    }