Java 以编程方式旋转可绘图或视图
Java 以编程方式旋转可绘图或视图,java,android,rotation,Java,Android,Rotation,deltaangle不超过0.1,我不确定提取值是多少。由于您试图使用Almero的Android手势检测器,我决定也这样做,以便找到合适的解决方案: private class RotateListener implements RotateGestureDetector.OnRotateGestureListener{ @Override public boolean onRotate(MotionEvent event1, MotionEvent event2,
deltaangle
不超过0.1,我不确定提取值是多少。由于您试图使用Almero的Android手势检测器,我决定也这样做,以便找到合适的解决方案:
private class RotateListener implements RotateGestureDetector.OnRotateGestureListener{
@Override
public boolean onRotate(MotionEvent event1, MotionEvent event2,
double deltaAngle) {
return true;
}
}
这对我来说很好(我可以用两个手指旋转手势来旋转ImageView。
注意:别忘了选择合适的旋转方法调用。我对这两种方法都进行了注释以引起您的注意。
旋转比只是一个乘数,可以加速我手指的旋转反应。
可以对视图使用任何旋转轴(setRotation()、setRotationX()和setRotationY())方法。
要在API级别低于11的Android设备(蜂窝设备之前)上支持此代码,您可能需要使用NineodelDroid库。以下代码围绕其中心旋转图像视图:
public class MainActivity extends Activity {
private RotateGestureDetector mRotateDetector;
private float mRotationDegrees = 0.f;
private static final float ROTATION_RATIO = 2;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRotateDetector = new RotateGestureDetector(getApplicationContext(), new RotateListener());
}
@Override
public boolean onTouchEvent(MotionEvent event) {
mRotateDetector.onTouchEvent(event);
return super.onTouchEvent(event);
}
private class RotateListener extends RotateGestureDetector.SimpleOnRotateGestureListener {
@Override
public boolean onRotate(RotateGestureDetector detector) {
mRotationDegrees -= detector.getRotationDegreesDelta();
ImageView v = (ImageView) findViewById(R.id.imageView);
// For NineOldAndroids library only!
ViewHelper.setRotation(v, mRotationDegrees * ROTATION_RATIO);
// For HONEYCOMB and later only!
v.setRotation(mRotationDegrees * ROTATION_RATIO);
return true;
}
}
}
下面是一个很好的解决方案,用于为imageView放置旋转的可绘制图形:
ImageView myImageView = (ImageView)findViewById(R.id.my_imageview);
AnimationSet animSet = new AnimationSet(true);
animSet.setInterpolator(new DecelerateInterpolator());
animSet.setFillAfter(true);
animSet.setFillEnabled(true);
final RotateAnimation animRotate = new RotateAnimation(0.0f, -90.0f,
RotateAnimation.RELATIVE_TO_SELF, 0.5f,
RotateAnimation.RELATIVE_TO_SELF, 0.5f);
animRotate.setDuration(1500);
animRotate.setFillAfter(true);
animSet.addAnimation(animRotate);
myImageView.startAnimation(animSet);
用法:
Drawable getRotateDrawable(final Bitmap b, final float angle) {
final BitmapDrawable drawable = new BitmapDrawable(getResources(), b) {
@Override
public void draw(final Canvas canvas) {
canvas.save();
canvas.rotate(angle, b.getWidth() / 2, b.getHeight() / 2);
super.draw(canvas);
canvas.restore();
}
};
return drawable;
}
另一种选择:
Bitmap b=...
float angle=...
final Drawable rotatedDrawable = getRotateDrawable(b,angle);
root.setImageDrawable(rotatedDrawable);
另外,如果你想旋转位图,但害怕OOM,你可以使用我制作的NDK解决方案@baboo它不起作用这对修复有好处,但我想要的是当我检测到旋转手势时的动态最终旋转动画rotate=新旋转动画(0.0f,360.0f,RotateAnimation.RELATIVE_TO_SELF,0.5f,RotateAnimation.RELATIVE_TO_SELF,0.5f);非常不可恢复的解决方案!!因为您正在重新实现“draw”功能,每次需要更新可绘制文件时,它都会被旋转。@Corbella说得通,这里的问题是什么?
Bitmap b=...
float angle=...
final Drawable rotatedDrawable = getRotateDrawable(b,angle);
root.setImageDrawable(rotatedDrawable);
private Drawable getRotateDrawable(final Drawable d, final float angle) {
final Drawable[] arD = { d };
return new LayerDrawable(arD) {
@Override
public void draw(final Canvas canvas) {
canvas.save();
canvas.rotate(angle, d.getBounds().width() / 2, d.getBounds().height() / 2);
super.draw(canvas);
canvas.restore();
}
};
}