android draganddrop

。。

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ImageView mImageView = (ImageView)findViewById(R.id.image);
        StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
        StrictMode.setVmPolicy(builder.build());
        builder.detectFileUriExposure();

        mImageView.setonTouchListener(new View.onTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent event) {
                if (event.getAction() == MotionEvent.ACTION_DOWN) {
                    if (Build.VERSION.SDK_INT >= 24) {
                        //通过Uri创建ClipData.Item对象,Uri是文件地址
                        final File folder = new File(Environment.getDataDirectory(), "system");
                        ClipData.Item item = new ClipData.Item(Uri.fromFile(new File(folder, "haha.jpg")));
                        //通过两个参数的构造函数创建ClipData
                        String[] mimeTypes = {"image/png"};
                        ClipData clipData = new ClipData(new ClipDescription("iamge drag", mimeTypes), item);
                        //建立shaldow
                        View.DragShadowBuilder shadowBuilder = new View.DragShadowBuilder(view);

                        view.startDragAndDrop(clipData, shadowBuilder, null, View.DRAG_FLAG_GLOBAL);
                    }
                    return true;
                } else {
                    return false;
                }
            }
        });
    }