我有这个简单的代码用onTouchListener旋转图像,但它似乎也在图像上放大和缩小。我真的很擅长使用onTouchListener。有人能告诉我发生了什么,或者如何解决这个问题。任何事情都有所帮助,谢谢:)
public class MainActivity extends Activity implements OnTouchListener {
private ImageView dialer;
private float y=0;
public boolean onTouch(View v, MotionEvent event) {
double r=Math.atan2(event.getX()-dialer.getWidth()/2, dialer.getHeight()/2-event.getY());
int rotation=(int)Math.toDegrees(r);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
break;
case MotionEvent.ACTION_MOVE:
//x=event.getX();
y=event.getY();
updateRotation(rotation);
break;
case MotionEvent.ACTION_UP:
break;
}//switch
return true;
}//onTouch
private void updateRotation(double rot){
float newRot= new Float(rot);
Bitmap bitmap=BitmapFactory.decodeResource(getResources(),R.drawable.round_button_big);
Matrix matrix= new Matrix();
matrix.postRotate(newRot,bitmap.getWidth()/2,bitmap.getHeight()/2);
if(y>250){
Bitmap reDrawnBitmap=Bitmap.createBitmap(bitmap,0,0,bitmap.getWidth(),bitmap.getHeight(),matrix,true);
dialer.setImageBitmap(reDrawnBitmap);
}
else{
Bitmap reDrawnBitmap=Bitmap.createBitmap(bitmap,0,0,bitmap.getWidth(),bitmap.getHeight(),matrix,true);
dialer.setImageBitmap(reDrawnBitmap);
}
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dialer = (ImageView) findViewById(R.id.image);
dialer.setOnTouchListener(this);
}//onCreate
}
答案 0 :(得分:1)
尝试在触摸事件中使用此代码:
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
// reset the touched quadrants
for (int i = 0; i < quadrantTouched.length; i++) {
quadrantTouched[i] = false;
}
allowRotating = false;
startAngle = getAngle(event.getX(), event.getY());
break;
case MotionEvent.ACTION_MOVE:
double currentAngle = getAngle(event.getX(), event.getY());
rotateDialer((float) (startAngle - currentAngle));
startAngle = currentAngle;
break;
case MotionEvent.ACTION_UP:
allowRotating = true;
break;
}
// set the touched quadrant to true
quadrantTouched[getQuadrant(event.getX() - (dialerWidth / 2), dialerHeight - event.getY() - (dialerHeight / 2))] = true;
detector.onTouchEvent(event);
return true;
在这里你可以找到一个例子:http://code.tutsplus.com/tutorials/android-sdk-creating-a-rotating-dialer--mobile-8868