当使用阴影的UILabel运行大量UIView动画时，设备会冻结，然后按“主页”按钮 [英] The device freezes when there are a lot of UIView animation running with UILabels using shadows and I press the Home button
问题描述
我的应用程序出现问题。当我在一个带有很多图标（UIViews）的屏幕中，并且每个图标都运行一个动画时，就会发生错误。该屏幕使人联想起跳板屏幕，动画效果也相似。什么也没做。甚至电源按钮也不起作用。并且图标继续晃动。
如果我取消了标签创建方法的调用，就不会发生。
有任何建议吗？
谢谢！
动画方法（从Three20 api中提取）：
-（void）wobble {
static BOOL wobblesLeft = NO;
如果（isEditing）
{
CGFloat旋转=（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（Icon * ic in iconList）
{
++ nWobblyButtons;
i ++;
if（i％2）
{
ic.transform = wobblesLeft吗？ wobbleRight：wobbleLeft;
}否则{
ic.transform = wobblesLeft吗？ wobbleLeft：wobbleRight;
}
}
if（nWobblyButtons> = 1）
{
[UIView setAnimationDuration：kWobbleTime];
[UIView setAnimationDelegate：self];
[UIView setAnimationDidStopSelector：@selector（wobble）];
wobblesLeft =！wobblesLeft;
}否则{
[NSObject cancelPreviousPerformRequestsWithTarget：self];
[self performSelector：@selector（wobble）withObject：n after afterlay：kWobbleTime];
}
[UIView commitAnimations];
}
}
标签创建
-（void）layoutLabel
{
//如果未构建标题。
if（_lblName == nil）
{
//创建新标签。
_lblName = [[UILabel alloc] initWithFrame：CGRectMake（LABEL_POS_X，
LABEL_POS_Y，
LABEL_WIDTH，
LABEL_HEIGHT）];
//清除背景。
[_lblName setBackgroundColor：[UIColor clearColor]];
//设置字体。
[_lblName setFont：[UIFont fontWithName：@ Helvetica-Bold size：11.3]]];
[_lblName setAdjustsFontSizeToFitWidth：NO];
//设置文本颜色
[_lblName setTextColor：[UIColor whiteColor]];
//调整行数。
[_lblName setNumberOfLines：2];
//调整对中位置。
[_lblName setTextAlignment：UITextAlignmentCenter];
//像springboad的图标一样调整阴影。
_lblName.layer.shadowOpacity = 1.0;
_lblName.layer.shadowRadius = 0.8;
_lblName.layer.shadowColor = [[UIColor blackColor] CGColor];
_lblName.layer.shadowOffset = CGSizeMake（0，1.2）;
//将标签添加到容器。
[self addSubview：_lblName];
}
}
问题是：
对于每个图标，我都有很多子视图，因此，每个图标在动画时的计算都会导致代码缓慢。
因此，我发现了一些解决方案。我建立了相同的图标结构，但是之后，我在下面的代码中合并了UIImage中的所有内容。
+（UIImage * ）imageWithView：（UIView *）view
{
UIGraphicsBeginImageContextWithOptions（view.bounds.size，view.opaque，0.0）;
[view.layer renderInContext：UIGraphicsGetCurrentContext（）];
UIImage * img = UIGraphicsGetImageFromCurrentImageContext（）;
UIGraphicsEndImageContext（）;
返回img;
}
这使我的FPS从约15增至60 Oo
遵循一些我发现的帮助
链接
I'm having some problems in my application. The error occurs when I'm in a screen with a lot of icons (UIViews), each one running a animation. This screen reminds the springboard screen, and the animation visual is similar too.
So, if I press the home button, the application doesn't goes to background and I can't do anything. Even the power button doesn't work. And the icons continue shaking.
If I remove the call for label creation method, this don't happens.
Any advice?
Thanks!
Animation method (extracted from Three20 api):
- (void)wobble {
static BOOL wobblesLeft = NO;
if (isEditing)
{
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(Icon *ic in iconList)
{
++nWobblyButtons;
i++;
if (i % 2)
{
ic.transform = wobblesLeft ? wobbleRight : wobbleLeft;
} else {
ic.transform = wobblesLeft ? wobbleLeft : wobbleRight;
}
}
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];
}
}
Label creation
-(void)layoutLabel
{
// If title isn`t builded.
if(_lblName == nil)
{
// Create new label.
_lblName = [[UILabel alloc] initWithFrame:CGRectMake(LABEL_POS_X,
LABEL_POS_Y,
LABEL_WIDTH,
LABEL_HEIGHT)];
// Clear the background.
[_lblName setBackgroundColor:[UIColor clearColor]];
// Sets the font.
[_lblName setFont:[UIFont fontWithName:@"Helvetica-Bold" size:11.3]];
[_lblName setAdjustsFontSizeToFitWidth:NO];
// Sets text color
[_lblName setTextColor:[UIColor whiteColor]];
// Adjust the number of lines.
[_lblName setNumberOfLines:2];
// Adjust the aligment to center.
[_lblName setTextAlignment:UITextAlignmentCenter];
// Adjust shadow like the springboad`s icons.
_lblName.layer.shadowOpacity = 1.0;
_lblName.layer.shadowRadius = 0.8;
_lblName.layer.shadowColor = [[UIColor blackColor] CGColor];
_lblName.layer.shadowOffset = CGSizeMake(0, 1.2);
// Add label to container.
[self addSubview:_lblName];
}
}
The problem is:
For each icon I have many subviews, so, the calculations of each icon, at animation time, resulted in a slow code.
So, I found some light to solve this. I builded the same icon structure, but, after, I merged everithing inside a UIImage with a code below.
+ (UIImage *) imageWithView:(UIView *)view
{
UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.opaque, 0.0);
[view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage * img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
This increased my FPS from ~15 to 60 O.o
Follow some help that I found Link
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