是否可以使拖影不透明？

Question

正如问题所述.这是我的dragshadowbuilder供参考.如您所知,拖动时创建的阴影是半透明的.反正有没有让它变得不透明？(完全稳固)

public class MyDragShadowBuilder extends View.DragShadowBuilder {
    View view;
    int width;
    int height;
    Bitmap bitmap;
    public MyDragShadowBuilder(View v) {
        super(v);
        view = v;
        ImageView b = (ImageView)view;
        int x = Character.getNumericValue(b.getContentDescription().charAt(0));
        int y = Character.getNumericValue(b.getContentDescription().charAt(1));
        bitmap = InGameActivity.currentBoardState[x][y].getPicture();
        width = bitmap.getWidth();
        height = bitmap.getHeight();
    }

    @Override
    public void onDrawShadow(Canvas canvas) {
        Rect source = new Rect(0, 0, InGameActivity.chessSquareHeightWidth, InGameActivity.chessSquareHeightWidth);
        canvas.drawBitmap(bitmap, null, source, null);
    }

    @Override
    public void onProvideShadowMetrics(Point shadowSize, Point touchPoint) {
        shadowSize.set(InGameActivity.chessSquareHeightWidth, InGameActivity.chessSquareHeightWidth);
        touchPoint.set(InGameActivity.chessSquareHeightWidth/2, InGameActivity.chessSquareHeightWidth/2);
    }
}

编辑:这是我目前的onTouch代码,我还将提供该应用程序的背景.

OnTouchListener myOnTouchListener = new OnTouchListener() {

                @Override
                public boolean onTouch(View view, MotionEvent event) {
                    System.out.println(event.toString());
                    if (event.getAction() == MotionEvent.ACTION_DOWN) {
                        ImageView b = (ImageView)view;
                        int x = Character.getNumericValue(b.getContentDescription().charAt(0));
                        int y = Character.getNumericValue(b.getContentDescription().charAt(1));
                        if (!currentBoardState[x][y].isEmpty()) {
                            ((ImageView)view).setImageBitmap(null);
                            DragShadowBuilder shadowBuilder = new MyDragShadowBuilder(view);  
                            view.startDrag(null, shadowBuilder, view, 0);
                        }

                        moveChessPiece;
                        return true;
                    }

                    return false;
                }
            });

好的,这就是你需要知道的.我正在开发一个象棋应用程序.我有一个8x8 GridLayout,我已经命名了currentBoardState.所以目前我希望能够拖动这件作品,但是我希望被拖动的作品是不透明的,这样用户就会觉得他/她实际上正在移动这件作品,而不是仅仅点击然后点击一个目的地就像我一样以前有它.

Answer 1

正如@Ernir所说,没有API获得DragShadow.但我们知道拖动位置和拖动视图,因此我们可以自己绘制它.

我写了一个简单的功能有限的演示,你可以在这里下载.

它实现了一个名为DragContainer的自定义ViewGroup,使用它将原始根视图包装在layout xml中.

<info.dourok.android.demo.DragContainer xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/root"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <!-- original root view -->
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">
         <!-- ... -->
    </RelativeLayout>

</info.dourok.android.demo.DragContainer>

调用DragContainer #startDragChild来开始拖动(演示有更多细节):

在活动中:

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mDragContainer = (DragContainer) findViewById(R.id.root);
        View drag = mDragContainer.findViewById(R.id.drag);
        View drop = mDragContainer.findViewById(R.id.drop);
        drag.setTag(IMAGEVIEW_TAG);
        drag.setOnLongClickListener(new View.OnLongClickListener() {
            public boolean onLongClick(View v) {
                ClipData.Item item = new ClipData.Item((CharSequence) v
                        .getTag());
                ClipData dragData = new ClipData((CharSequence) v.getTag(),
                        new String[] { ClipDescription.MIMETYPE_TEXT_PLAIN },
                        item);
                return mDragContainer.startDragChild(v, dragData, // the data to
                                                                    // be
                                                                    // dragged
                        null, // no need to use local data
                        0 // flags (not currently used, set to 0)
                        );

            }
        });


    }

您还可以扩展DragContainer以绘制自定义拖动阴影,这是您的需求的示例.

public class MyDragContainer extends DragContainer {
    public MyDragContainer(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public MyDragContainer(Context context) {
        super(context, null);
    }

    public MyDragContainer(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    int width;
    int height;
    Bitmap bitmap;

    @Override
    protected void onSetDragTarget(View v) {
        ImageView b = (ImageView) v;
        int x = Character.getNumericValue(b.getContentDescription().charAt(0));
        int y = Character.getNumericValue(b.getContentDescription().charAt(1));
        bitmap = InGameActivity.currentBoardState[x][y].getPicture();
        width = bitmap.getWidth();
        height = bitmap.getHeight();
    }

    @Override
    protected void drawDragShadow(Canvas canvas) {
        Rect source = new Rect(0, 0, InGameActivity.chessSquareHeightWidth, InGameActivity.chessSquareHeightWidth);

        int w =  InGameActivity.chessSquareHeightWidth;
        int h = InGameActivity.chessSquareHeightWidth;

        canvas.translate(getDragX() - w / 2, getDragY() - h / 2);

        canvas.drawBitmap(bitmap, null, source, null);
    }
}

我希望它会有所帮助.

Answer 2

不知道是否有人知道它，我们可以使用标志DRAG_FLAG_OPAQUE来实现相同的功能，因此对应的startDrag方法如下所示：

    View.DragShadowBuilder dragShadowBuilder = new View.DragShadowBuilder(view);
    view.startDrag(clipData, dragShadowBuilder, view, DRAG_FLAG_OPAQUE);