Question

当我触摸图像按钮时，我正在处理图像按钮，图像按钮应该显示一次缩放或缩小，并转到下一个活动。任何人都可以在此处拥有源代码吗？

Answer 1

以下是为ImageView添加放大，缩小功能的代码。

class Acitivty implements View.OnTouchListener //


private static final String TAG = "Touch";
@SuppressWarnings("unused")
private static final float MIN_ZOOM = 1f,MAX_ZOOM = 1f;

// These matrices will be used to scale points of the image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();

// The 3 states (events) which the user is trying to perform
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;

// these PointF objects are used to record the point(s) the user is touching
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;


//TODO 
image.setOnTouchListener(this);


@Override
public boolean onTouch(View v, MotionEvent event)
{
    ImageView view = (ImageView) v;
    view.setScaleType(ImageView.ScaleType.MATRIX);
    float scale;

    dumpEvent(event);
    // Handle touch events here...

    switch (event.getAction() & MotionEvent.ACTION_MASK)
    {
        case MotionEvent.ACTION_DOWN:   // first finger down only
            matrix.set(view.getImageMatrix());
            savedMatrix.set(matrix);
            start.set(event.getX(), event.getY());
            Log.d(TAG, "mode=DRAG"); // write to LogCat
            mode = DRAG;
            break;

        case MotionEvent.ACTION_UP: // first finger lifted

        case MotionEvent.ACTION_POINTER_UP: // second finger lifted

            mode = NONE;
            Log.d(TAG, "mode=NONE");
            break;

        case MotionEvent.ACTION_POINTER_DOWN: // first and second finger down

            oldDist = spacing(event);
            Log.d(TAG, "oldDist=" + oldDist);
            if (oldDist > 5f) {
                savedMatrix.set(matrix);
                midPoint(mid, event);
                mode = ZOOM;
                Log.d(TAG, "mode=ZOOM");
            }
            break;

        case MotionEvent.ACTION_MOVE:

            if (mode == DRAG)
            {
                matrix.set(savedMatrix);
                matrix.postTranslate(event.getX() - start.x, event.getY() - start.y); // create the transformation in the matrix  of points
            }
            else if (mode == ZOOM)
            {
                // pinch zooming
                float newDist = spacing(event);
                Log.d(TAG, "newDist=" + newDist);
                if (newDist > 5f)
                {
                    matrix.set(savedMatrix);
                    scale = newDist / oldDist; // setting the scaling of the
                    // matrix...if scale > 1 means
                    // zoom in...if scale < 1 means
                    // zoom out
                    matrix.postScale(scale, scale, mid.x, mid.y);
                }
            }
            break;
    }

    view.setImageMatrix(matrix); // display the transformation on screen

    return true; // indicate event was handled
}

/*
 * --------------------------------------------------------------------------
 * Method: spacing Parameters: MotionEvent Returns: float Description:
 * checks the spacing between the two fingers on touch
 * ----------------------------------------------------
 */

private float spacing(MotionEvent event)
{
    float x = event.getX(0) - event.getX(1);
    float y = event.getY(0) - event.getY(1);
    return (float)Math.sqrt(x * x + y * y);
}

/*
 * --------------------------------------------------------------------------
 * Method: midPoint Parameters: PointF object, MotionEvent Returns: void
 * Description: calculates the midpoint between the 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);
}

/** 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("Touch Events ---------", sb.toString());
}

如何在触摸图像按钮时添加zoon或缩小？

1 个答案: