1.没有自动装箱的masonry的使用
// 自动布局 在这之前需要想把控件添加到父控件中
[_segmentedControl mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.top.equalTo(self.view).offset(10);
make.right.equalTo(self.view).offset(-10);
make.height.mas_equalTo(40);
}];
[_tableView mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.right.bottom.equalTo(self.view);
make.top.mas_equalTo(_segmentedControl.mas_bottom).offset(10);
}];
[_noMessagesView mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.right.bottom.equalTo(self.view);
make.top.mas_equalTo(_segmentedControl.mas_bottom).offset(10);
}];
2.获取系统返回pop手势
- (void)addScreenGesture {
// 1.获取系统自带滑动手势的target对象
id target = self.navigationController.interactivePopGestureRecognizer.delegate;
// 2.创建全屏滑动手势,调用系统自带手势的target的滑动方法
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:target action:@selector(handleNavigationTransition:)];
// 3.给控制器的view添加全屏滑动手势
[self.view addGestureRecognizer:panGesture];
}
3.忽略未使用变量警告
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wunused-variable"
UIView *eTestView = [[UIView alloc] init];
#pragma clang diagnostic pop
4.忽略方法未声明警告
#pragma
clang diagnostic push
#pragma clang diagnostic ignored "-Wundeclared-selector"
UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc]
initWithTarget:targetaction:@selector(handleNavigationTransition:)];
#pragma
clang diagnostic pop
5.忽略任意警告
Snip20160913_3.png
结合上面忽略警告的方式,以后你会忽略警告了吗?
忽略一个类文件的警告
Snip20160913_4.png
6.在APPDelegate中禁用第三方键盘
#pragma mark - 禁用第三方键盘
- (BOOL)application:(UIApplication
*)application shouldAllowExtensionPointIdentifier:(NSString
*)extensionPointIdentifier {
return NO;
}
7.Alert提示宏定义
#define Alert(_S_, ...) [[[UIAlertView
alloc] initWithTitle:@"提示" message:[NSString stringWithFormat:(_S_), ##__VA_ARGS__]
delegate:nil cancelButtonTitle:@"知道了" otherButtonTitles:nil] show]
8.不使用typedef定义block的方式使用block
- (void)isIdentify:(void(^)(BOOL identify, NSError *error))finished;
9.NSDateFormatter的线程安全优化方法
static NSString *const kCurrentDateFormatter = @"currentDateFormatter";
+ (instancetype)dateFormatter {
NSMutableDictionary *threadDict = [NSThread currentThread].threadDictionary;
WLDateFormatter *dateFormatter = threadDict[kCurrentDateFormatter];
if (!dateFormatter) {
@synchronized (self) {
if (!dateFormatter) {
dateFormatter = [WLDateFormatter new];
threadDict[kCurrentDateFormatter] = dateFormatter;
return dateFormatter;
}
return dateFormatter;
}
}
return dateFormatter;
static id _instance;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
_instance = [WLDateFormatter new];
});
return _instance;
}
10.字符串去掉空格
NSString *str = @" 王启镰 王俨 王迅 王朝 ";// 去掉所有的空格NSString *replaceStr = [str stringByReplacingOccurrencesOfString:@" " withString:@""];// 去掉前后的空格NSString *characterSetStr = [str stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
11.打印字符串地址
strK = @"This is a String!";
NSLog(@"strK = %p", strK);
12.设置圆角的优化
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 200, 200)];
[self.view addSubview:view];
view.layer.cornerRadius = 8;
view.layer.masksToBounds = YES;
view.layer.shouldRasterize = YES;
view.layer.rasterizationScale = [UIScreen mainScreen].scale;
13.数字处理,尽量使用高精度的double
NSString *str = @"123456789.99";
CGFloat floatN = [str floatValue];
double doubleN = [str doubleValue];
NSLog(@"floatN = %f", floatN);
NSLog(@"doubleN = %f", doubleN);
/* 打印结果
2016-07-13 17:22:24.673 WYTestDemo[12699:4390961]
floatN = 123456792.000000
2016-07-13 17:22:24.673 WYTestDemo[12699:4390961]
doubleN = 123456789.990000
**/
14.获取启动图的名称[项目启动后会对launchImage中的图片进行2次命名]
- (NSString *)fetchLaunchImageName
{
NSArray* imagesDict = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];
for (NSDictionary* dict in imagesDict) {
if(CGSizeEqualToSize(CGSizeFromString(dict[@"UILaunchImageSize"]),[UIScreen mainScreen].bounds.size))
{
return dict[@"UILaunchImageName"];
}
}
return nil;
}
15.字符串包含iOS7.0适配
NSString *text = @"10.5%~12.25%";
// iOS 8专有API
BOOL isContainsPercent = [textcontainsString:@"%@"];
// 如果要支持iOS7 请用这个
BOOL isContain = [@"%" rangeOfString:self.text].length > 0;
16.获取UIWebView的JSContext
JSContext *context = [self.secondPage valueForKeyPath:@"documentView.webView.mainFrame.javaScriptContext"];
context[@"sendUrl"] = ^{
NSArray *args = [JSContext currentArguments];
if(args.count > 0){
WLWebController *webVC = [[WLWebController alloc] init];
webVC.url = [NSString stringWithFormat:@"%@",args[0]];
[self.navigationController pushViewController:webVC animated:YES];
}
};
17.约束优先级
Snip20160913_5.png
Content Compression Resistance Priority，也叫内容压缩阻力优先级（小名：别挤我），该优先级越高，则越晚轮到被压缩。
Content Hugging Priority，也叫内容紧靠优先级（小名：别扯我），该优先级越高，这越晚轮到被拉伸。
18. 选中tabBar的跳转,先选中tabBar,把当前导航控制器popToRootViewController,然后用选中tabBar的导航控制器push出一个页面
// 这里的mainVC 的类型是UITabBarController
mainVC.selectedIndex = 0;
[weakSelf.navigationController popToRootViewControllerAnimated:NO];
WLBFinanceViewController
*finance = [[WLBFinanceViewController alloc] init];
finance.pageType= kFinancePageTypeStandard;
[mainVC.viewControllers[0] popToRootViewControllerAnimated:NO];
[mainVC.viewControllers[0] pushViewController:financeanimated:YES];
19.在iOS中一个汉字占3个字节
20.模拟器真机判断
#if TARGET_IPHONE_SIMULATOR //模拟器
#elif TARGET_OS_IPHONE //真机
#endif
21.使用SDWebImage保存图片到本地
[[SDImageCache sharedImageCache] storeImage:image forKey:imageUrl];
22.给UIWebView设置请求头
NSDictionary *dictionnary =@{@"UserAgent":userAgent};
[[NSUserDefaults standardUserDefaults] registerDefaults:dictionnary];
23.获取UIWebView的UserAgent
UIWebView *tempWebView = [[UIWebView alloc]init];
NSString* userAgent = [tempWebView stringByEvaluatingJavaScriptFromString:@"navigator.userAgent"];
24.NSArray和NSDictionary去除NSNull处理
static id WYJSONObjectByRemovingNullValues(id JSONObject) {
if ([JSONObject isKindOfClass:[NSArray class]]) {
NSMutableArray *mutableArray = [NSMutableArray arrayWithCapacity:[(NSArray *)JSONObject count]];
for (id value in (NSArray *)JSONObject) {
[mutableArray addObject:WYJSONObjectByRemovingNullValues(value)];
}
return mutableArray.copy;
} else if ([JSONObject isKindOfClass:[NSDictionary class]]) {
NSMutableDictionary *mutableDictionary = [NSMutableDictionary dictionaryWithDictionary:JSONObject];
for (id key in [(NSDictionary *)JSONObject allKeys]) {
id value = (NSDictionary *)JSONObject[key];
if (!value || [value isEqual:[NSNull null]]) {
[mutableDictionary removeObjectForKey:key];
} else if ([value isKindOfClass:[NSArray class]] || [value isKindOfClass:[NSDictionary class]]) {
mutableDictionary[key] = WYJSONObjectByRemovingNullValues(value);
}
}
return mutableDictionary.copy;
}
return JSONObject;
}
25.Xcode中支持的模拟器所在的位置
**/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport
26.NSNumber可以自动去掉小数点后边的0**
double number = 60000.00;
NSLog(@"number = %@", @(number));
/* 打印结果
2016-08-23 17:22:13.988 NSAttributeString换行[5256:259641] number = 60000
**/
// 特殊情况
NSString *str = @"8.54";
double number = [str doubleValue];
NSLog(@"number = %@", @(number));
/* 打印结果
**2016-08-25 18:10:57.988 ****绘制虚线****[20270:1205620] number = 8.539999999999999**
**/
27.对数字类型进行判断
int number = 2.00;
NSNumber *myNumber = @(number);
if (strcmp([myNumberobjCType], @encode(double)) == 0) {
NSLog(@"我是double");
} else if (strcmp([myNumber objCType], @encode(int)) == 0) {
NSLog(@"我是int");
} else if (strcmp([myNumber objCType], @encode(float)) == 0) {
NSLog(@"我是float");
} else if (strcmp([myNumber objCType], @encode(BOOL)) == 0) {
NSLog(@"我是BOOL");
}
28.定义和使用C语言数组
CGFloat colHeight[5];
for (int i =0; i< 5; ++i){
colHeight[i] = i;
}
29.NSRunLoop的正确开启方式
BOOL shouldKeepRunning = YES; // global NSRunLoop *theRL = [NSRunLoop currentRunLoop]; while (shouldKeepRunning && [theRL runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]]);/** 在需要关闭运行循环的地方设置shouldKeepRunning为No即可.因为如果直接使用[NSRunLoop run]当移除输入源过后,不能保证运行循环能够终止.*/
30.屏幕尺寸
1.屏幕大小
iPhone4做原型时，可以用320×480
iPhone5做原型时，可以用320×568
iPhone6做原型时，可以用375×667
iPhone6Plus原型，可以用414×736
2.屏幕分辨率
iPhone4的显示分辨率，640×960
iPhone5的显示分辨率，640×1136
iPhone6的显示分辨率，1334×750
iPhone6 Plus显示为，1920×1080
31.页面不添加标记进行一次性判断
if (objc_getAssociatedObject(self, _cmd)) {
NSLog(@"已经加载过啦");
} else {
objc_setAssociatedObject(self, _cmd, @"Launch", OBJC_ASSOCIATION_RETAIN);
NSLog(@"第一次加载");
}