Question

我想在我的应用程序的同一视图中使用双指缩放和拖放。

我可以单独实现它们但是当我尝试使用它们时它不起作用。

以下是拖动代码

class MyClickListener implements OnLongClickListener {

    @Override
    public boolean onLongClick(View view) {

        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
        );
        return true;
    }
}

当我在非自定义视图上使用而无需缩放来缩放时，此方法正常。

当我使用具有scalegesture侦听器的自定义视图，然后将MyClickListener设置为LongClickListener时，我只获得缩放功能，并且不会启动拖动。

我在检测到长按视图

后，尝试将拖动代码直接添加到自定义视图中

public class TouchImageView extends View {
long time = 0;
private Drawable image;
private float scaleFactor = 1.0f;
private ScaleGestureDetector scaleGestureDetector;

public TouchImageView(Context context) {
    super(context);
}

public TouchImageView(Context context, Drawable mImage) {
    super(context);

    image = mImage;
    setFocusable(true);
    image.setBounds(0, 0, image.getIntrinsicWidth(),
            image.getIntrinsicHeight());
    scaleGestureDetector = new ScaleGestureDetector(context,
            new ScaleListener());
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    // Set the image bounderies
    canvas.save();
    canvas.scale(scaleFactor, scaleFactor);
    image.draw(canvas);
    canvas.restore();
}

@Override
public boolean onTouchEvent(MotionEvent event) {

    if (event.getPointerCount() > 1) {
        scaleGestureDetector.onTouchEvent(event);
        invalidate();
    } else {
        int action = MotionEventCompat.getActionMasked(event);

        switch(action){
        case MotionEvent.ACTION_DOWN:
            time = SystemClock.elapsedRealtime();
            Log.i(EJ.TAG, time+"");
            break;

        case MotionEvent.ACTION_UP:
            long time1 = SystemClock.elapsedRealtime() - time;

            if(time1 >= 1000){

                ClipData.Item item = new ClipData.Item((CharSequence) this.getTag());

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

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

                //Toast.makeText(context, "Long press", Toast.LENGTH_SHORT).show();

                return true;
            }

            break;              
        }

    }

    return true;
}

private class ScaleListener extends
        ScaleGestureDetector.SimpleOnScaleGestureListener {
    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        scaleFactor *= detector.getScaleFactor();

        // don't let the object get too small or too large.
        scaleFactor = Math.max(0.1f, Math.min(scaleFactor, 5.0f));

        invalidate();
        return true;
    }
}

 }

我不确定这是否是正确的做法。对此有任何帮助表示赞赏

Answer 1

查看下面给出的演示，了解缩放，平移和缩放功能。希望它有所帮助。

Example 1

Example 2

您可以询问是否有任何进一步的疑问：）。

快乐的编码！

使用捏缩放，在同一视图上拖放

1 个答案: