Question

我想检测View内触摸的对象。

这是我的View

public class TouchView extends View {
private Matrix translate;
private Bitmap image, background;
private float scaleFactor = 1.0f;
private ScaleGestureDetector scaleGestureDetector;
private GestureDetector simpleOnGestureListener;

public TouchView(Context context) {
    super(context);
    translate = new Matrix();
    image = BitmapFactory.decodeResource(context.getResources(), R.drawable.photo);

    //background = decodeFile(R.drawable.background);
    scaleGestureDetector = new ScaleGestureDetector(context, new ScaleListener());
    simpleOnGestureListener = new GestureDetector(context, new MyGestureListener(this));

}


@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    canvas.save();
    canvas.scale(scaleFactor, scaleFactor);
    canvas.drawBitmap(background, translate, null);
    canvas.drawBitmap(image, translate, null);
    Matrix m = canvas.getMatrix();
    canvas.restore();
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    scaleGestureDetector.onTouchEvent(event);
    simpleOnGestureListener.onTouchEvent(event);
    invalidate();
    return true;
}


private class MyGestureListener extends GestureDetector.SimpleOnGestureListener {
    private static final String DEBUG_TAG = "Gestures";
    TouchView view;

    public MyGestureListener(TouchView view) {
        this.view = view;
    }

    @Override
    public boolean onDown(MotionEvent event) {
        return true;
    }

    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
        view.onMove(-distanceX, -distanceY);
        invalidate();
        return true;
    }


}

private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
    @Override
    public boolean onScale(ScaleGestureDetector detector) {

        scaleFactor *= detector.getScaleFactor();
        scaleFactor = Math.max(0.6f, Math.min(scaleFactor, 2.0f));

        invalidate();
        return true;
    }
}

public Bitmap decodeFile(int resId) {
    try {
        //decode image size
        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeResource(getContext().getResources(), resId, o);
        //find the correct scale value. it should be the power of 2.
        final int REQUIRED_SIZE = 70;
        int width_tmp = o.outWidth, height_tmp = o.outHeight;
        int scale = 1;
        while (true) {
            if (width_tmp / 2 < REQUIRED_SIZE
                    || height_tmp / 2 < REQUIRED_SIZE)
                break;
            width_tmp /= 2;
            height_tmp /= 2;
            scale++;
        }

        //decode wit inSampleSize
        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize = scale;
        return BitmapFactory.decodeResource(getContext().getResources(), resId, o2);
    } catch (Exception e) {
        e.getStackTrace();
    }
    return null;
}

public void onMove(float dx, float dy) {
    translate.postTranslate(dx, dy);
    invalidate();
}

}

有没有办法检测照片是否被点击或背景？我想让你们两个都可以移动，但如果我点击照片我想手动移动它。不是整个观点。

亲切的问候！

Answer 1

我并不完全明白你想要什么。但是，正如我从您的代码中发现的那样，您希望在视图中显示两个图像（背景和前景）。您需要检查触摸位置（使用getX（）和getY（））。如果前景图像矩形包含该点，则触摸您的对象，否则触摸背景。

在Android中的View中检测触摸的对象

1 个答案: