我一直在尝试编写一个将图像旋转到特定角度的活动方法.
旋转有效,但问题是方法每隔一秒左右调用一次,但只在前几次旋转.
在某个点上,动画的图像只是静止不动,即使动画正在设置并以不同的值开始!假设移动图像,就像前几次一样.
private void animateNeedle(final float sfAngle)
{
final View viewNeedle = findViewById(R.id.needle);
final RotateAnimation needleAnimation;
RotateAnimation anim;
anim = new RotateAnimation( 0,sfAngle,m_nNeedleWidth / 2,m_nNeedleHeight);
anim.setDuration(200);
anim.setFillAfter(true);
viewNeedle.setAnimation(anim);
anim.setAnimationListener(new AnimationListener()
{
@Override
public void onAnimationEnd(final Animation animation)
{
viewNeedle.clearAnimation();
}
@Override
public void onAnimationRepeat(final Animation animation)
{
// TODO Auto-generated method stub
}
@Override
public void onAnimationStart(final Animation animation)
{
// TODO Auto-generated method stub
}
});
anim.start();
findViewById(android.R.id.content).postInvalidate();
}
最佳答案
问题是它没有在主线程上运行,修复我们使用的:
anim = new RotateAnimation( m_lastAngle,viewNeedle.getWidth() / 2,viewNeedle.getHeight());
anim.setDuration(1000);
anim.setFillAfter(true);
viewNeedle.setAnimation(anim);
anim.setAnimationListener(new AnimationListener()
{
@Override
public void onAnimationEnd(final Animation animation)
{
// viewNeedle.clearAnimation();
}
@Override
public void onAnimationRepeat(final Animation animation)
{
// TODO Auto-generated method stub
}
@Override
public void onAnimationStart(final Animation animation)
{
m_lastAngle = sfAngle;
}
});
runOnUiThread(new Runnable()
{
@Override
public void run()
{
viewNeedle.startAnimation(anim);
findViewById(android.R.id.content).invalidate();
}
});
我们还使用了:
final View viewNeedle = findViewById(R.id.needle);
viewNeedle.getViewTreeObserver().addOnGlobalLayoutListener(
new OnGlobalLayoutListener()
{
@Override
public void onGlobalLayout()
{
scaleView(viewNeedle);
}
/**
* Scale a view.
*
* @param viewToScale - View to scale.
*/
private void scaleView(final View viewToScale)
{
int height = (int) (viewToScale.getHeight() / GraphicsPoint
.getScalePoint().y);
int width = (int) (viewToScale.getWidth() / GraphicsPoint
.getScalePoint().x);
final LayoutParams layoutParams = viewToScale
.getLayoutParams();
layoutParams.height = height;
layoutParams.width = width;
viewToScale.setLayoutParams(layoutParams);
viewToScale.getViewTreeObserver()
.removeOnGlobalLayoutListener(this);
}
});