我已将我的项目转换为
Xcode 6,以便为iOS 8构建.但是,特定的UILabel会导致应用程序在添加到视图层次结构时崩溃.这是我收到的唯一错误日志：
-[MyViewController _contentInsetsFromFonts]: unrecognized selector sent to instance 0x16d90da0
我无法在项目中的任何位置找到contentInsetsFromFonts方法.此外,我甚至无法在网上任何地方找到它的参考,包括Apple的文档.我没有为这个UIViewController使用NIB,因此UI是在loadView方法中构建的：
- (void)loadView {
UIImage *trackImage = [UIImage imageNamed:@"sliderTrack.png"];
sliderBackground = [[UIImageView alloc] initWithImage:trackImage];
UIView *view = [[UIView alloc] initWithFrame:sliderBackground.frame];
[view addSubview:sliderBackground];
slider = [[UiSlider alloc] initWithFrame:sliderBackground.frame];
CGRect sliderFrame = slider.frame;
sliderFrame.size.width -= 46;
slider.frame = sliderFrame;
slider.center = sliderBackground.center;
slider.backgroundColor = [UIColor clearColor];
[slider setMinimumTrackImage:[UIImage imageNamed:@"sliderMaxMinTrackImage.png"] forState:UIControlStateNormal];
[slider setMaximumTrackImage:[UIImage imageNamed:@"sliderMaxMinTrackImage.png"] forState:UIControlStateNormal];
UIImage *thumbImage = [UIImage imageNamed:@"cancel-slider.png"];
[slider setThumbImage:thumbImage forState:UIControlStateNormal];
slider.minimumValue = 0.0;
slider.maximumValue = 1.0;
slider.continuous = YES;
slider.value = 0.0;
// Set the slider action methods
[slider addTarget:self
action:@selector(sliderUp:)
forControlEvents:UIControlEventTouchUpInside];
[slider addTarget:self
action:@selector(sliderDown:)
forControlEvents:UIControlEventTouchDown];
[slider addTarget:self
action:@selector(sliderChanged:)
forControlEvents:UIControlEventValueChanged];
NSString *labelText = @"label text";
UIFont *labelFont;
NSString *osVersion = [[UIDevice currentDevice] systemVersion];
if ([osVersion floatValue] >= 7.0) {
labelFont = [UIFont systemFontOfSize:22.0];
} else {
labelFont = [UIFont systemFontOfSize:24.0];
}
CGSize labelSize = [labelText sizeWithAttributes:[NSDictionary dictionaryWithObjectsAndKeys:labelFont,NSFontAttributeName,nil]];
label = [[UILabel alloc] initWithFrame:CGRectMake(0.0,0.0,labelSize.width,labelSize.height)];
CGFloat labelHorizontalCenter = slider.center.x + (thumbImage.size.width / 2);
label.center = CGPointMake(labelHorizontalCenter,slider.center.y);
// Set other label attributes and add it to the view
label.textColor = [UIColor whiteColor];
label.textAlignment = NSTextAlignmentCenter;
label.backgroundColor = [UIColor clearColor];
label.font = labelFont;
label.text = labelText;
[view addSubview:label];
[view addSubview:slider];
label.layer.delegate = self;
self.view = view;
}
该应用程序不会在[view addSubview：label]中崩溃;它在loadView方法返回后崩溃.
解决方法
从
the
UIView documentation开始：
Never change the delegate of this layer object.
删除此行：
label.layer.delegate = self;
无论你想在这里完成什么,你都需要以另一种方式去做.
