Question

我试图获得缩放效果，我面临的问题很少

当图像的宽度和高度大于imageview中的图像时，以缩放显示。我希望我的图像应该是imageview的大小。
虽然我已经设置了最大和最小变焦的限制，然后我尝试缩放比我的图像更改位置。

这是我的代码

public class display_page extends Activity {
Bitmap org_bmp, bmp;
ImageView img;
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();

// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;

// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1.0f;
private float MAX_ZOOM = 1.25f;
private float MIN_ZOOM = 0.25f;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.display_image);
    init();
    final String path = getIntent().getStringExtra("imagePath");
    org_bmp = BitmapFactory.decodeFile(path);
    // Drawable img_drawable = Drawable.createFromPath(path);

    img.setImageBitmap(org_bmp);
    img.setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            // TODO Auto-generated method stub
            // img.setImageMatrix(matrix);

            switch (event.getAction() & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_DOWN:
                savedMatrix.set(matrix);
                start.set(event.getX(), event.getY());
                mode = DRAG;
                break;
            case MotionEvent.ACTION_POINTER_DOWN:
                oldDist = spacing(event);
                if (oldDist > 10f) {
                    savedMatrix.set(matrix);
                    midPoint(mid, event);
                    mode = ZOOM;
                }
                break;
            case MotionEvent.ACTION_UP:

            case MotionEvent.ACTION_POINTER_UP:
                mode = NONE;
                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);
                    if (newDist > 10f) {
                        matrix.set(savedMatrix);
                        float scale = newDist / oldDist;
                        matrix.postScale(scale, scale, mid.x, mid.y);

                        float[] values = new float[9];
                        matrix.getValues(values);
                        float scaleX = values[Matrix.MSCALE_X];
                        float scaleY = values[Matrix.MSCALE_Y];
                        if (scaleX > MAX_ZOOM) {
                            scaleX = MAX_ZOOM;
                        } else if (scaleX < MIN_ZOOM) {
                            scaleX = MIN_ZOOM;
                        }

                        if (scaleY > MAX_ZOOM) {
                            scaleY = MAX_ZOOM;
                        } else if (scaleY < MIN_ZOOM) {
                            scaleY = MIN_ZOOM;
                        }

                        values[Matrix.MSCALE_X] = scaleX;
                        values[Matrix.MSCALE_Y] = scaleY;
                        matrix.setValues(values);
                    }
                }
                break;

            }
            // Bitmap resizedImage = Bitmap.createBitmap(bitmap, 0,
            // 0,bitmap.getWidth(),bitmap.getHeight(), matrix, true);
            // limitZoom(matrix);
            // limitDrag(matrix);
            img.setImageMatrix(matrix);
            return true;
        }
    });

}

private void init() {
    // TODO Auto-generated method stub
    img = (ImageView) findViewById(R.id.image);

}

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);
}

请帮助我并纠正我的代码。提前致谢

Answer 1

我搜索了很多这个问题，但最后我得到了这个link的确切解决方案。这段代码对我很有用。

如何正确获得缩放效果？

1 个答案: