animateWithDurationを途中で止める

アニメーション実行
[UIView animateWithDuration:10.0f animations:^{
    targetView.frame=CGRectMalke(0.0,0.0,100.0,100.0);
} completion:^(BOOL finished) {
    
}];

アニメーション中止
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView animateWithDuration:0.001 animations:^{
    targetView.alpha = 1.0;
}];