我试图获得缩放效果,我面临的问题很少
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