Question

我是Android新手。我已经完成了图片视图的缩放。现在面临一些问题。 1）无法设置缩放级别。 2）图像也在移动。我想阻止它这是我的代码：

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.show_image);
    imageView1 = (ImageView) findViewById(R.id.showImageView1);
    imageView2 = (ImageView) findViewById(R.id.Food_pic2);
    // get image path from list View
    Intent intent = getIntent();
    int path1 = intent.getIntExtra("image1", 0);
    int path2 = intent.getIntExtra("image2", 0);
    imageView1.setImageResource(path1);
    imageView1.setOnTouchListener(this);

}

这是我的Touch听众

    @Override
public boolean onTouch(View v, MotionEvent event) {

    ImageView view = (ImageView) v;
    dumpEvent(event);

    // Handle touch events here...
    switch (event.getAction() & MotionEvent.ACTION_MASK) {
    case MotionEvent.ACTION_DOWN:
        savedMatrix.set(matrix);
        start.set(event.getX(), event.getY());
        Log.d(TAG, "mode=DRAG");
        mode = DRAG;
        break;
    case MotionEvent.ACTION_POINTER_DOWN:
        oldDist = spacing(event);
        Log.d(TAG, "oldDist=" + oldDist);
        if (oldDist > 10f) {
            savedMatrix.set(matrix);
            midPoint(mid, event);
            mode = ZOOM;
            Log.d(TAG, "mode=ZOOM");
        }
        break;
    case MotionEvent.ACTION_UP:
    case MotionEvent.ACTION_POINTER_UP:
        mode = NONE;
        Log.d(TAG, "mode=NONE");
        savedMatrix.set(matrix);

        break;
    case MotionEvent.ACTION_MOVE:

        if (mode == DRAG) {

            matrix.set(savedMatrix);
            matrix.postTranslate(event.getX() - start.x, event.getY()
                    - start.y);
        } else if (mode == ZOOM) {
            float newDist = spacing(event);
            Log.d(TAG, "newDist=" + newDist);
            if (newDist > 10f) {
                matrix.set(savedMatrix);
                float scale = newDist / oldDist;
                matrix.postScale(scale, scale, mid.x, mid.y);
            }
        }
        break;
    }

    view.setImageMatrix(matrix);

    return true;

}

/** Show an event in the LogCat view, for debugging */
private void dumpEvent(MotionEvent event) {
    String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE",
            "POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
    StringBuilder sb = new StringBuilder();
    int action = event.getAction();
    int actionCode = action & MotionEvent.ACTION_MASK;
    sb.append("event ACTION_").append(names[actionCode]);
    if (actionCode == MotionEvent.ACTION_POINTER_DOWN
            || actionCode == MotionEvent.ACTION_POINTER_UP) {
        sb.append("(pid ").append(
                action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
        sb.append(")");
    }
    sb.append("[");
    for (int i = 0; i < event.getPointerCount(); i++) {
        sb.append("#").append(i);
        sb.append("(pid ").append(event.getPointerId(i));
        sb.append(")=").append((int) event.getX(i));
        sb.append(",").append((int) event.getY(i));
        if (i + 1 < event.getPointerCount())
            sb.append(";");
    }
    sb.append("]");
    Log.d(TAG, sb.toString());
}

/** Determine the space between the first two fingers */
private float spacing(MotionEvent event) {

    float x = event.getX(0) - event.getX(1);
    float y = event.getY(0) - event.getY(1);
    return FloatMath.sqrt(x * x + y * y);
}

/** Calculate the mid point of the first two fingers */
private void midPoint(PointF point, MotionEvent event) {
    float x = event.getX(0) + event.getX(1);
    float y = event.getY(0) + event.getY(1);
    point.set(x / 2, y / 2);
}

我搜索并查看与此相关的最大值。但我无法解决我的问题。

我如何以及在何处编写用于设置缩放级别和停止移动图像视图的代码。

提前致谢。

Answer 1

这就是运动发生的地方：

if (mode == DRAG) {

            matrix.set(savedMatrix);
            matrix.postTranslate(event.getX() - start.x, event.getY()
                    - start.y);
        }

如果你不想移动，那么在if块内部什么都不做。

如果您不想让用户放大或缩小，那么您也可以将此部分留空：

else if (mode == ZOOM) {
            float newDist = spacing(event);
            Log.d(TAG, "newDist=" + newDist);
            if (newDist > 10f) {
                matrix.set(savedMatrix);
                float scale = newDist / oldDist;
                // i edited here.
                //i  set zoom level here 
                matrix.getValues(matrixValues);
                float currentScale = matrixValues[Matrix.MSCALE_X];
                if (scale * currentScale > MAX_ZOOM) {
                    scale = MAX_ZOOM / currentScale;
                } else if (scale * currentScale < MIN_ZOOM) {
                    scale = MIN_ZOOM / currentScale;
                }

                matrix.postScale(scale, scale, mid.x, mid.y);
            }
        }

如果您想设置缩放级别，就在view.setImageMatrix(matrix)之前，您可以使用

手动缩放图像

matrix.postScale(val1,val2,val3,val4);

使用函数内部的值来获取所需的缩放级别，因为这是设置缩放级别的功能。

无法设置图像缩放级别并修复图像视图

1 个答案: