Question

我试图实现android拖放。我得到输出：我有两个布局，从第一个布局我可以将图标或图像拖到下一个布局。我的问题是我无法改变我的图像并合并视图。任何建议都将对我有所帮助。谢谢

public class MainActivity extends Activity {

    private ImageView myImage,myImage1,myImage2,myImage3;
    private static final String IMAGEVIEW_TAG = "The Android Logo";
    private static final String IMAGEVIEW_TAG1 = "The Android Logo1";
    private static final String IMAGEVIEW_TAG2 = "The Android Logo2";
    private static final String IMAGEVIEW_TAG3 = "The Android Logo3";

/** Called when the activity is first created. */

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        myImage = (ImageView)findViewById(R.id.image);
        myImage1 = (ImageView)findViewById(R.id.image1);
        myImage2 = (ImageView)findViewById(R.id.image2);
        myImage3 = (ImageView)findViewById(R.id.image3);

        // Sets the tag
        myImage.setTag(IMAGEVIEW_TAG);
        myImage1.setTag(IMAGEVIEW_TAG1);
        myImage2.setTag(IMAGEVIEW_TAG2);
        myImage3.setTag(IMAGEVIEW_TAG3);

        // set the listener to the dragging data
        myImage.setOnLongClickListener(new MyClickListener());
        myImage1.setOnLongClickListener(new MyClickListener());
        myImage2.setOnLongClickListener(new MyClickListener());
        myImage3.setOnLongClickListener(new MyClickListener());

        findViewById(R.id.toplinear).setOnDragListener(new MyDragListener());
        findViewById(R.id.bottomlinear).setOnDragListener(new MyDragListener());

    }

    private final class MyClickListener implements OnLongClickListener {

        // called when the item is long-clicked
        @Override
        public boolean onLongClick(View view) {
        // TODO Auto-generated method stub

            // create it from the object's tag
            ClipData.Item item = new ClipData.Item((CharSequence)view.getTag());

            String[] mimeTypes = { ClipDescription.MIMETYPE_TEXT_PLAIN };
            ClipData data = new ClipData(view.getTag().toString(), mimeTypes, item);
            DragShadowBuilder shadowBuilder = new View.DragShadowBuilder(view);

            view.startDrag( data, //data to be dragged
                            shadowBuilder, //drag shadow
                            view, //local data about the drag and drop operation
                            0   //no needed flags
                          );


            view.setVisibility(View.INVISIBLE);
            return true;
        }   
    }

    class MyDragListener implements OnDragListener {
        Drawable normalShape = getResources().getDrawable(R.drawable.normal_shape);
        Drawable targetShape = getResources().getDrawable(R.drawable.target_shape);

        @Override
        public boolean onDrag(View v, DragEvent event) {

            // Handles each of the expected events
            switch (event.getAction()) {

            //signal for the start of a drag and drop operation.
            case DragEvent.ACTION_DRAG_STARTED:
                // do nothing
                break;

            //the drag point has entered the bounding box of the View
            case DragEvent.ACTION_DRAG_ENTERED:
                v.setBackground(targetShape);   //change the shape of the view
                break;

            //the user has moved the drag shadow outside the bounding box of the View
            case DragEvent.ACTION_DRAG_EXITED:
                v.setBackground(normalShape);   //change the shape of the view back to normal
                break;

            //drag shadow has been released,the drag point is within the bounding box of the View
            case DragEvent.ACTION_DROP:
                // if the view is the bottomlinear, we accept the drag item
                  if(v == findViewById(R.id.bottomlinear)) {
                      View view = (View) event.getLocalState();
                      ViewGroup viewgroup = (ViewGroup) view.getParent();
                      viewgroup.removeView(view);

                      //change the text
                    //  TextView text = (TextView) v.findViewById(R.id.text);
                    //  text.setText("The item is dropped");

                     GridLayout containView = (GridLayout) v;
                      containView.addView(view);
                      view.setVisibility(View.VISIBLE);
                  } else {
                      View view = (View) event.getLocalState();
                      view.setVisibility(View.VISIBLE);
                      Context context = getApplicationContext();
                      Toast.makeText(context, "You can't drop the image here", 
                                                 Toast.LENGTH_LONG).show();
                      break;
                   }
                  break;

            //the drag and drop operation has concluded.
            case DragEvent.ACTION_DRAG_ENDED:
                v.setBackground(normalShape);   //go back to normal shape

            default:
                break;
            }
            return true;
        }
    }
}

Answer 1

您无法对图像进行随机播放并合并视图的原因是因为您没有正确处理丢弃事件。

看一下这个Drag and Drop开源示例：

https://github.com/theredsunrise/AndroidCoolDragAndDropGridView

Android拖放（无法移动图像）

1 个答案: