"长按实现视图抖动和删除"功能知识点整理

一、功能细分

1、对视图添加长按手势的识别：｛ UILongPressGestureRecognizer类的使用｝

UILongPressGestureRecognizer *longPressRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPress:)];

longPressRecognizer.allowableMovement = 30;

[testView addGestureRecognizer:longPressRecognizer];        

[longPressRecognizer release];

 

 

2、删除一个视图后，改变其它视图的位置，可以通过修改其center的值来实现：

如 tempView.center = tempViewCenter;

 

3、抖动的实现：｛修改view的 transform值来改变视图的旋转过的角度；通过动画来实现动态角度转动；当动画结束后再时其转动相反角度，也动画实现，如此反复即可。｝

- (void)wobble {

static BOOL wobblesLeft = NO;

if (isShake) {

CGFloat rotation = (kWobbleRadians * M_PI) / 180.0;

CGAffineTransform wobbleLeft = CGAffineTransformMakeRotation(rotation);

CGAffineTransform wobbleRight = CGAffineTransformMakeRotation(-rotation);

[UIView beginAnimations:nil context:nil];

NSInteger i = 0;

NSInteger nWobblyButtons = 0;

for (UIView *tempView in [scrollView subviews]) {

if ([tempView isKindOfClass:[TestView class]] || [tempView isKindOfClass:[UIButton class]]) {

++nWobblyButtons;

if (i % 2) {

tempView.transform = wobblesLeft ? wobbleRight : wobbleLeft;

} else {

tempView.transform = wobblesLeft ? wobbleLeft : wobbleRight;

}

++i;

}

}

if (nWobblyButtons >= 1) {

[UIView setAnimationDuration:kWobbleTime];

[UIView setAnimationDelegate:self];

[UIView setAnimationDidStopSelector:@selector(wobble)];

wobblesLeft = !wobblesLeft;

} else {

[NSObject cancelPreviousPerformRequestsWithTarget:self];

[self performSelector:@selector(wobble) withObject:nil afterDelay:kWobbleTime];

}

[UIView commitAnimations];

}

}

4、停止抖动：

tempView.transform = CGAffineTransformIdentity;

二、知识点整理

1、

UIGestureRecognizer 手势识别类

2、

NSValue的使用

 

 

3、

CGAffineTransform

 

CGFloat rotation = (kWobbleRadians * M_PI) / 180.0;

CGAffineTransform wobbleLeft = CGAffineTransformMakeRotation(rotation);

CGAffineTransform wobbleRight = CGAffineTransformMakeRotation(-rotation);

 

tempView.transform = CGAffineTransformIdentity;

 

4、UIView类中一些不常用到的内容

如：uiview.transform

5、NSObject类中一些不常用的内容

如：[NSObject cancelPreviousPerformRequestsWithTarget:self];

[self performSelector:@selector(wobble) withObject:nil afterDelay:kWobbleTime];

6、NSTimer的使用