UIButton文字和图标间距：
[button setImageEdgeInsets:UIEdgeInsetsMake(0.0, -20, 0.0, 0.0)];
UITabbarItem的图标大小改变：
vc.tabBarItem.imageInsets = UIEdgeInsetsMake(6, 0, -6, 0);
UISearchBar设置取消按钮的文字:
[UIBarButtonItem appearanceWhenContainedInInstancesOfClasses:@[[UISearchBar class]]].title = @"取消";
自定义Tabbarcontroller：
- (void)setup {
self.tabBar.tintColor = [UIColor initWith:Color_Hex_Main];
self.tabBar.backgroundColor = [[UIColor whiteColor]colorWithAlphaComponent:0.96];
self.tabBar.translucent = NO;
[self addChildVC:[HomePageVC class] withTitle:@"首页" withIconName:ImgName_home];
[self addChildVC:[CategoryPageVC class] withTitle:@"分类" withIconName:ImgName_sort];
[self addChildVC:[GrouppurchasePageVC class] withTitle:@"团购" withIconName:ImgName_Group_purchase];
[self addChildVC:[CartPageVC class] withTitle:@"购物车" withIconName:ImgName_shopping_cart];
[self addChildVC:[MinePageVC class] withTitle:@"我的" withIconName:ImgName_my];
}
- (void)addChildVC:(Class )str withTitle:(NSString *)title withIconName:(NSString *)iconName {
UIViewController *vc = [[str alloc]init];
BaseNavVC *nav = [[BaseNavVC alloc]initWithRootViewController:vc];
if ([title isEqualToString:@"团购"]) {
vc.tabBarItem.imageInsets = UIEdgeInsetsMake(6, 0, -6, 0);
}else{
vc.title = title;
}
vc.tabBarItem.image = [UIImage imageNamed:iconName];
vc.tabBarItem.image = [UIImage imageNamed:[iconName stringByAppendingString:@"_d"]];
nav.navigationBar.barTintColor = [UIColor initWith:Color_Hex_Main];
nav.navigationBar.backgroundColor = [UIColor initWith:Color_Hex_Main];
[self addChildViewController:nav];
}
UITabbarItem显示图标本身颜色：
vc.tabBarItem.image = [[UIImage imageNamed:iconName]imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
vc.tabBarItem.selectedImage = [[UIImage imageNamed:[iconName stringByAppendingString:@"_d"]]imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
UITableViewCell仅仅更新视图布局：
//仅仅更新视图高度、这两个方法会让所有的cell重新布局，然后重新计算高度。
[tableView beginUpdates];
[tableView endUpdates];
UITableViewCell selectedBackgroundView修改位置：
重载：
- (void )layoutSubviews {
// always try to set frame in layoutSubviews
[super layoutSubviews];
// CGRect frame = CGRectMake(52.0, 0, self.width-67.0, self.height);
CGRect frame = CGRectMake(self.contentView.originX+15.0, 0, self.contentView.width-30.0, self.height);
UIView *backView = [[UIView alloc] initWithFrame:frame];
[backView addCommonShadow:4.0];
[backView addLine: self.contentView.width-30.0 distance:38 isDistanceTop:NO];
self.selectedBackgroundView = backView;
self.selectedBackgroundView.backgroundColor = [UIColor whiteColor];
}
UITableViewCell 选择图标修改：
- (void)layoutSubviews
{
[super layoutSubviews];
for (UIControl *control in self.subviews) {
if (![control isMemberOfClass:NSClassFromString(@"UITableViewCellEditControl")]){
continue;
}
[control mas_makeConstraints:^(MASConstraintMaker *make) {
make.centerY.equalTo(self);
make.right.mas_offset(-30.0);
}];
for (UIView *subView in control.subviews) {
if (![subView isKindOfClass: [UIImageView class]]) {
continue;
}
UIImageView *imageView = (UIImageView *)subView;
if (self.selected) {
// KVC修改
//修改选中背景图片等
} else {
//修改非选中背景图片等
}}}
iOS 应用跳转到设置界面:
NSURL *url = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
if ([[UIApplication sharedApplication] canOpenURL:url]) {
[[UIApplication sharedApplication] openURL:url];
}
疑问:
GCC 有个visibility属性, 该属性是说, 启用这个属性:
1. 当-fvisibility=hidden时
动态库中的函数默认是被隐藏的即 hidden. 除非显示声明为__attribute__((visibility("default"))).
2. 当-fvisibility=default时
动态库中的函数默认是可见的.除非显示声明为__attribute__((visibility("hidden"))).
特别说明: 这个特性是 GCC4.0 以后才有的.
NSMutableArray便利构造器
NSMutableArray *marr=[NSMutableArrayarrayWithCapacity:5];
带有capacity的方法,
其内存原理如下:
capacity后的NSUInteger代表了开辟内存的一个单位
初始在内存中开辟5个内存,如果之后数组元素多余5个,则会再开辟新的5*2个新的内存,[考虑到数组的连续内存的特性]
单位是以5,把之前的5个元素的内容拷贝到新的十个新的内存里面,把第六个
也放进去,然后释放初始状态创建的内存5个
最后得到了一块够用的连续的内存5*2
如果创建的framework中使用了category类，则在使用framework的项目配置中【Other Linker Flags】需要添加参数【-ObjC]或者【-all_load】。
如果使用framework的使用出现【Umbrella header for module 'XXXX' does not include header 'XXXXX.h'】,是因为错把xxxxx.h拖到了public中。
如果出现【dyld: Library not loaded:XXXXXX】，是因为打包的framework版本太高。比如打包framework时，选择的是iOS 9.0，而实际的工程环境是iOS 8开始的。
指令集对应的设备
armv6
iPhone、iPhone 3G
iPod 1G、iPod 2G
armv7
iPhone 3GS、iPhone 4
iPod 3G、iPod 4G、iPod 5G
iPad、iPad 2、iPad 3、iPad Mini
armv7s
iPhone 5、iPhone 5C
iPad 4
arm64
iPhone 5s iPhone 6iPhone 6P iPhone 6s iPhone 6sP iPhone 7 iPhone 7P
iPad Air, Retina iPad Mini
判断当前设备是否为iPhone X
#define KIsiPhoneX ([UIScreen instancesRespondToSelector:@selector(currentMode)] ? CGSizeEqualToSize(CGSizeMake(1125, 2436), [[UIScreen mainScreen] currentMode].size) : NO)