Android imageView放大，縮小和旋轉

Question

嗨，我是Android應用程序的新手，我想放大，縮小Roation ImageView.I嘗試了大部分示例，但在imageview中的所有圖像中都獲取放大和縮小。任何人都可以建議我嗎？

Answer 1

非常成功的放大和縮小imageview。我會推薦它很容易使用。 here

Answer 2

以下的代碼可以幫助你實現雙指縮放上的ImageView

public class ZoomActivity extends Activity implements 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; 

/** Called when the activity is first created. */ 
@Override 
public void onCreate(Bundle savedInstanceState) 
{ 
super.onCreate(savedInstanceState); 
setContentView(R.layout.busmaps); 
ImageView view = (ImageView) findViewById(R.id.imageViewmaps1); 
view.setOnTouchListener(this); 
} 

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

    // Handle touch events here... 

switch (event.getAction() & MotionEvent.ACTION_MASK) 
{ 
    case MotionEvent.ACTION_DOWN: // first finger down only 
             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 
} 



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); 
} 



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); 
}