资料
- iOS 6
- iOS 7
- iOS 8
- iOS 9
- iOS 10
面试
Tips
-
Swift打印内存地址
println(" str value \(str) has address: \(unsafeAddressOf(str))")
-
Obj-C屏蔽警告
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
...
#pragma clang diagnostic pop
-
打印代码文件中函数的调用过程
clang -rewrite-objc xxx.m -
UIWebView获取Html标题
-(void)webViewDidFinishLoad:(UIWebView *)webView {
titleLabel.text = [webView stringByEvaluatingJavaScriptFromString:@"document.title"];
｝
-
Category添加属性字段
@interface UIImage (category)
// 在UIImage中新建一个tag属性
@property (nonatomic, copy) NSString *tag;
@end
static const void *tagKey = &tagKey;
@implementation UIImage (category)
-(NSString *)tag {
return objc_getAssociatedObject(self, tagKey);
}
-(void)setTag:(NSString *)tag {
objc_setAssociatedObject(self, tagKey, tag, OBJC_ASSOCIATION_COPY_NONATOMIC);
}
@end
-
隐藏状态栏
override func prefersStatusBarHidden() -> Bool { return true }
-
Runloop实现Alert同步弹窗
-(NSInteger)doModal {
[self showAlert];
_bModel = YES;
while (_bModel) {
[[NSRunLoop mainRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
}
return _selectBtnIndex;
}
-(void)showAlert {
UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"" message:@"okookoko" delegate:self cancelButtonTitle:@"cancel" otherButtonTitles:@"ok", nil];
[alertView show];
}
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
_selectBtnIndex = buttonIndex;
_bModel = NO;
}
-
UITableView的Group样式下顶部空白处理
//分组列表头部空白处理
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, 0.1)];
self.tableView.tableHeaderView = view;
-
禁止锁屏
默认情况下，当设备一段时间没有触控动作时，iOS会锁住屏幕。但有一些应用是不需要锁屏的，比如视频播放器。
[UIApplication sharedApplication].idleTimerDisabled = YES;
-
模态推出透明界面
UIViewController *vc = [[UIViewController alloc] init];
UINavigationController *na = [[UINavigationController alloc] initWithRootViewController:vc];
if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)
{
na.modalPresentationStyle = UIModalPresentationOverCurrentContext;
} else {
self.modalPresentationStyle=UIModalPresentationCurrentContext;
}
[self presentViewController:na animated:YES completion:nil];
-
Xcode调试不显示内存占用
editSCheme 里面有个选项叫叫做enable zoombie Objects 取消选中
-
显示隐藏文件
//显示
defaults write com.apple.finder AppleShowAllFiles -bool true
killall Finder
//隐藏
defaults write com.apple.finder AppleShowAllFiles -bool false
killall Finder
-
iOS跳转到App Store下载应用评分
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"itms-apps://itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews?type=Purple+Software&id=APPID"]];
-
手动更改iOS状态栏的颜色
-(void)setStatusBarBackgroundColor:(UIColor *)color
{
UIView *statusBar = [[[UIApplication sharedApplication] valueForKey:@"statusBarWindow"] valueForKey:@"statusBar"];
if ([statusBar respondsToSelector:@selector(setBackgroundColor:)])
{
statusBar.backgroundColor = color;
}
}
-
获取实际使用的LaunchImage图片
-(NSString *)getLaunchImageName
{
CGSize viewSize = self.window.bounds.size;
// 竖屏
NSString *viewOrientation = @"Portrait";
NSString *launchImageName = nil;
NSArray* imagesDict = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];
for (NSDictionary* dict in imagesDict)
{
CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);
if (CGSizeEqualToSize(imageSize, viewSize) && [viewOrientation isEqualToString:dict[@"UILaunchImageOrientation"]])
{
launchImageName = dict[@"UILaunchImageName"];
}
}
return launchImageName;
}
-
在当前屏幕获取第一响应
UIWindow * keyWindow = [[UIApplication sharedApplication] keyWindow];
UIView * firstResponder = [keyWindow performSelector:@selector(firstResponder)];
-
判断对象是否遵循了某协议
if ([self.selectedController conformsToProtocol:@protocol(RefreshPtotocol)])
{
[self.selectedController performSelector:@selector(onTriggerRefresh)];
}
-
判断view是不是指定视图的子视图
BOOL isView = [textView isDescendantOfView:self.view];
-
NSArray 快速求总和 最大值 最小值 和 平均值
NSArray *array = [NSArray arrayWithObjects:@"2.0", @"2.3", @"3.0", @"4.0", @"10", nil];
CGFloat sum = [[array valueForKeyPath:@"@sum.floatValue"] floatValue];
CGFloat avg = [[array valueForKeyPath:@"@avg.floatValue"] floatValue];
CGFloat max =[[array valueForKeyPath:@"@max.floatValue"] floatValue];
CGFloat min =[[array valueForKeyPath:@"@min.floatValue"] floatValue];
NSLog(@"%f\n%f\n%f\n%f",sum,avg,max,min);
-
修改UITextField中Placeholder的文字颜色
[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
-
关于NSDateFormatter的格式
G: 公元时代，例如AD公元
yy: 年的后2位
yyyy: 完整年
MM: 月，显示为1-12
MMM: 月，显示为英文月份简写,如 Jan
MMMM: 月，显示为英文月份全称，如 Janualy
dd: 日，2位数表示，如02
d: 日，1-2位显示，如 2
EEE: 简写星期几，如Sun
EEEE: 全写星期几，如Sunday
aa: 上下午，AM/PM
H: 时，24小时制，0-23
K：时，12小时制，0-11
m: 分，1-2位
mm: 分，2位
s: 秒，1-2位
ss: 秒，2位
S: 毫秒
-
获取一个类的所有子类
+(NSArray *) allSubclasses
{
Class myClass = [self class];
NSMutableArray *mySubclasses = [NSMutableArray array];
unsigned int numOfClasses;
Class *classes = objc_copyClassList(&numOfClasses;);
for (unsigned int ci = 0; ci < numOfClasses; ci++)
{
Class superClass = classes[ci];
do{
superClass = class_getSuperclass(superClass);
} while (superClass && superClass != myClass);
if (superClass)
{
[mySubclasses addObject: classes[ci]];
}
}
free(classes);
return mySubclasses;
}
-
监测设备是否设置了代理，需要CFNetwork.framework
NSDictionary *proxySettings = (__bridge NSDictionary *)(CFNetworkCopySystemProxySettings());
NSArray *proxies = (__bridge NSArray *)(CFNetworkCopyProxiesForURL((__bridge CFURLRef _Nonnull)([NSURL URLWithString:@"http://www.baidu.com"]), (__bridge CFDictionaryRef _Nonnull)(proxySettings)));
NSLog(@"\n%@",proxies);
NSDictionary *settings = proxies[0];
NSLog(@"%@",[settings objectForKey:(NSString *)kCFProxyHostNameKey]);
NSLog(@"%@",[settings objectForKey:(NSString *)kCFProxyPortNumberKey]);
NSLog(@"%@",[settings objectForKey:(NSString *)kCFProxyTypeKey]);
if ([[settings objectForKey:(NSString *)kCFProxyTypeKey] isEqualToString:@"kCFProxyTypeNone"])
{
NSLog(@"没代理");
}
else
{
NSLog(@"设置了代理");
}
-
取消UICollectionView的隐式动画
UICollectionView在reloadItems的时候，默认会附加一个隐式的fade动画，有时候很讨厌，尤其是当你的cell是复合cell的情况下(比如cell使用到了UIStackView)。
下面几种方法都可以帮你去除这些动画
//方法一
[UIView performWithoutAnimation:^{
[collectionView reloadItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:index inSection:0]]];
}];
//方法二
[UIView animateWithDuration:0 animations:^{
[collectionView performBatchUpdates:^{
[collectionView reloadItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:index inSection:0]]];
} completion:nil];
}];
//方法三
[UIView setAnimationsEnabled:NO];
[self.trackPanel performBatchUpdates:^{
[collectionView reloadItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:index inSection:0]]];
} completion:^(BOOL finished) {
[UIView setAnimationsEnabled:YES];
}];
-
让Xcode的控制台支持LLDB类型的打印
打开终端输入三条命令:
touch ~/.lldbinit
echo display @import UIKit >> ~/.lldbinit
echo target stop-hook add -o \"target stop-hook disable\" >> ~/.lldbinit
- CocoaPods pod install/pod update更新慢的问题
pod install --verbose --no-repo-update
pod update --verbose --no-repo-update
如果不加后面的参数，默认会升级CocoaPods的spec仓库，加一个参数可以省略这一步，然后速度就会提升不少
-
GCD timer定时器
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
dispatch_source_t timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0,queue);
dispatch_source_set_timer(timer,dispatch_walltime(NULL, 0),1.0*NSEC_PER_SEC, 0); //每秒执行
dispatch_source_set_event_handler(timer, ^{
//@"倒计时结束，关闭"
dispatch_source_cancel(timer);
dispatch_async(dispatch_get_main_queue(), ^{
});
});
dispatch_resume(timer);
- 禁用UIWebView的默认交互行为
public func webViewDidFinishLoad(webView: UIWebView) {
if disableUserSelect { // 禁用用户选择
webView.stringByEvaluatingJavaScriptFromString("document.documentElement.style.webkitUserSelect='none';")
}
if disableLongTouch { // 禁用长按弹出框
webView.stringByEvaluatingJavaScriptFromString("document.documentElement.style.webkitTouchCallout='none';")
}
}
- UIButton 移除所有事件
button.removeTarget(nil, action: nil, forControlEvents: .AllEvents)
- 在模拟器中添加视频
//Add a video in Simulator
if let a = NSBundle.mainBundle().pathForResource("test", ofType: "mov", inDirectory: nil) {
UISaveVideoAtPathToSavedPhotosAlbum(a, self, nil, nil)
}
- 液晶时钟字体
label.font=[UIFont fontWithName:@"DBLCDTempBlack" size:60.0];
- UIAlertController改变按钮文字颜色
alertC.view.tintColor = your color;
//setting the tintColor after presenting the controller works on both iOS 8 and 9
问题集锦
-
Can't add self as subview
iOS7刚发布的时候，总是出现这个 Can't add self as subview 的崩溃，异常描述和崩溃堆栈是这样的：
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Can't add self as subview'
这是因为导航栏在做动画的时候，执行了一次[self addSubView:self]
为了防止这种情况，我们在UINavigationController基类中加入防御，具体做法是在push，pop方法中设置一个标志位(animating=YES)，在动画结束之后，再重置这个标志位，然后，用这个标志位判断push和pop操作是否能够执行。
@interface UIViewController (Animating)
@property (nonatomic, assign) BOOL animating;
@end
@implementation BaseNavigationController
-(void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
{
if (topVC.animating) {
return;
}
topVC.animating = YES;
viewController.animating = YES;
[super pushViewController:viewController animated:animated];
}
@end
@implementation BaseKitViewController
-(void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
self.animating = NO;
}
-(void)viewDidDisappear:(BOOL)animated {
[super viewDidDisappear:animated];
self.animating = NO;
}
@end
-
TestFlight上传不成功提示ITSAppUsesNonExemptEncryption
info.plist添加下面键值对
<key>ITSAppUsesNonExemptEncryption</key><false/>
-
Xcode8 手动创建桥接文件Bridge-Header
-
Xib颜色设置有色差
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