无法设置图像缩放级别并修复图像视图

Question

我是 Android 的新手。我已经放大了图像视图。现在面临一些问题。 1）不能设置缩放级别。 2）图像也在移动。我想停止 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);

}

这是我的触摸监听器

    @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);
}

我搜索并看到与此相关的最大值。但我无法解决我的问题。

我如何以及在何处编写代码来设置缩放级别并停止移动我的图像视图。

提前致谢。

Answer 1

这是运动发生的地方：

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 块内什么都不做。

如果您也不想被用户放大或缩小，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);
            }
        }

如果你想设置缩放级别，就在view.setImageMatrix(matrix) 之前，你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得所需的缩放级别，因为这是设置缩放级别的函数。