1.任意位置拿到导航控制器

    UITabBarController*tabBarVc = (UITabBarController*)[UIApplicationsharedApplication].keyWindow.rootViewController;
    UINavigationController*nav = (UINavigationController*)tabBarVc.selectedViewController;
    [nav pushViewController:loginController animated:YES];

2.用masonry自适应label高度和宽度

label.preferredMaxLayoutWidth = width;// 如果是多行的话给一个maxWidth
[yourLabel setContentHuggingPriority:UILayoutPriorityRequired forAxis:UILayoutConstraintAxisHorizontal];

3.copy设置导航右键

-(void)setRightBtn
{
    //右导航
    _shareBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    _shareBtn.frame = CGRectMake(ScreenWidth-50, 20, 66, 29);
    [_shareBtn setTitleColor:UIColor.redColor forState:UIControlStateNormal];
    [_shareBtn setTitle:@"分享" forState:0];
    _shareBtn.titleLabel.font = [UIFont fontWithName:@"PingFangSC-Regular" size:15];
    
    _shareBtn.contentHorizontalAlignment = UIControlContentHorizontalAlignmentRight;
    [_shareBtn addTarget:self action:@selector(shareBtnClick) forControlEvents:UIControlEventTouchUpInside];
    UIBarButtonItem *rightBtn = [[UIBarButtonItem alloc] initWithCustomView:_shareBtn];
    self.navigationItem.rightBarButtonItem = rightBtn;

}

4.正确使用cocoaPods 在OC中集成Charts第三方库

https://blog.csdn.net/u010733679/article/details/80492342
http://www.hangge.com/blog/cache/detail_2122.html
https://cloud.tencent.com/developer/article/1336386

5.Runtime实用

/* 获取对象的所有属性，不包括属性值 */
- (NSArray *)getAllProperties:(id)obj
{
    u_int count;
    objc_property_t *properties = class_copyPropertyList([obj class], &count);
    NSMutableArray *propertiesArray = [NSMutableArray arrayWithCapacity:count];
    
    for (int i = 0; i<count; i++)
    {
        const char* propertyName =property_getName(properties[i]);
        [propertiesArray addObject: [NSString stringWithUTF8String: propertyName]];
    }
    
    free(properties);
    return propertiesArray;
}

/* 获取对象的所有属性 以及属性值 */
- (NSDictionary *)properties_aps
{
    NSMutableDictionary *props = [NSMutableDictionary dictionary];
    unsigned int outCount, i;
    objc_property_t *properties = class_copyPropertyList([self class], &outCount);
    
    for (i = 0; i<outCount; i++)
    {
        objc_property_t property = properties[i];
        const char* char_f =property_getName(property);
        NSString *propertyName = [NSString stringWithUTF8String:char_f];
        
        id propertyValue = [self valueForKey:(NSString *)propertyName];
        if (propertyValue) [props setObject:propertyValue forKey:propertyName];
    }
    free(properties);
    return props;
}

/* 获取对象的所有方法 */
-(void)printMothList
{
    unsigned int mothCout_f =0;
    Method* mothList_f = class_copyMethodList([self class],&mothCout_f);
    for(int i=0;i<mothCout_f;i++)
    {
        
        Method temp_f = mothList_f[i];
        IMP imp_f = method_getImplementation(temp_f);
        SEL name_f = method_getName(temp_f);
        const char* name_s =sel_getName(method_getName(temp_f));
        int arguments = method_getNumberOfArguments(temp_f);
        const char* encoding =method_getTypeEncoding(temp_f);
        NSLog(@"方法名：%@,参数个数：%d,编码方式：%@",[NSString stringWithUTF8String:name_s],
              arguments,[NSString stringWithUTF8String:encoding]);
        
    }
    free(mothList_f);
}

6.设置系统uiTableViewCell的UiImageView的大小

cell.imageView.image = [UIImage imageNamed:@""];
CGSize itemSize = CGSizeMake(44, 44);
UIGraphicsBeginImageContextWithOptions(itemSize, NO, UIScreen.mainScreen.scale);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
[cell.imageView.image drawInRect:imageRect];
cell.imageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

7.webview清楚缓存

NSString *libraryDir = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,   
NSUserDomainMask, YES)[0];
NSString *bundleId  =  [[[NSBundle mainBundle] infoDictionary]   
objectForKey:@"CFBundleIdentifier"];
NSString *webkitFolderInLib = [NSString stringWithFormat:@"%@/WebKit",libraryDir];
NSString *webKitFolderInCaches = [NSString   
stringWithFormat:@"%@/Caches/%@/WebKit",libraryDir,bundleId];
 NSString *webKitFolderInCachesfs = [NSString   
 stringWithFormat:@"%@/Caches/%@/fsCachedData",libraryDir,bundleId];

NSError *error;
/* iOS8.0 WebView Cache的存放路径 */
[[NSFileManager defaultManager] removeItemAtPath:webKitFolderInCaches error:&error];
[[NSFileManager defaultManager] removeItemAtPath:webkitFolderInLib error:nil];

/* iOS7.0 WebView Cache的存放路径 */
[[NSFileManager defaultManager] removeItemAtPath:webKitFolderInCachesfs error:&error];

8.推出透明视图

SMSViewController *pvc = [[SMSViewController alloc]init];
pvc.view.backgroundColor = [UIColor colorWithWhite:0 alpha:0.4];
pvc.modalPresentationStyle = UIModalPresentationOverCurrentContext|UIModalPresentationFullScreen; 
[self presentViewController:pvc animated:YES completion:^{
 }];

9.view添加动画

[view.layer addAnimation:[self opacityForever_Animation:0.5] forKey:nil];
#pragma mark === 永久闪烁的动画 ======
-(CABasicAnimation *)opacityForever_Animation:(float)time
{
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"opacity"];//必须写opacity才行。
    animation.fromValue = [NSNumber numberWithFloat:1.0f];
    animation.toValue = [NSNumber numberWithFloat:0.0f];//这是透明度。
    animation.autoreverses = YES;
    animation.duration = time;
    animation.repeatCount = MAXFLOAT;
    animation.removedOnCompletion = NO;
    animation.fillMode = kCAFillModeForwards;
    animation.timingFunction=[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];///没有的话是均匀的动画。
    return animation;
}
#pragma mark =====横向、纵向移动===========
-(CABasicAnimation *)moveX:(float)time X:(NSNumber *)x
{
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.translation.x"];///.y的话就向下移动。
    animation.toValue = x;
    animation.duration = time;
    animation.removedOnCompletion = NO;//yes的话，又返回原位置了。
    animation.repeatCount = MAXFLOAT;
    animation.fillMode = kCAFillModeForwards;
    return animation;
}
 
#pragma mark =====缩放-=============
-(CABasicAnimation *)scale:(NSNumber *)Multiple orgin:(NSNumber *)orginMultiple durTimes:(float)time Rep:(float)repertTimes
{
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
    animation.fromValue = Multiple;
    animation.toValue = orginMultiple;
    animation.autoreverses = YES;
    animation.repeatCount = repertTimes;
    animation.duration = time;//不设置时候的话，有一个默认的缩放时间.
    animation.removedOnCompletion = NO;
    animation.fillMode = kCAFillModeForwards;
    return  animation;
}
 
#pragma mark =====组合动画-=============
-(CAAnimationGroup *)groupAnimation:(NSArray *)animationAry durTimes:(float)time Rep:(float)repeatTimes
{
    CAAnimationGroup *animation = [CAAnimationGroup animation];
    animation.animations = animationAry;
    animation.duration = time;
    animation.removedOnCompletion = NO;
    animation.repeatCount = repeatTimes;
    animation.fillMode = kCAFillModeForwards;
    return animation;
}
 
#pragma mark =====路径动画-=============
-(CAKeyframeAnimation *)keyframeAnimation:(CGMutablePathRef)path durTimes:(float)time Rep:(float)repeatTimes
{
    CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
    animation.path = path;
    animation.removedOnCompletion = NO;
    animation.fillMode = kCAFillModeForwards;
    animation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
    animation.autoreverses = NO;
    animation.duration = time;
    animation.repeatCount = repeatTimes;
    return animation;
}
 
#pragma mark ====旋转动画======
-(CABasicAnimation *)rotation:(float)dur degree:(float)degree direction:(int)direction repeatCount:(int)repeatCount
{
    CATransform3D rotationTransform = CATransform3DMakeRotation(degree, 0, 0, direction);
    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform"];
    animation.toValue = [NSValue valueWithCATransform3D:rotationTransform];
    animation.duration  =  dur;
    animation.autoreverses = NO;
    animation.cumulative = NO;
    animation.fillMode = kCAFillModeForwards;
    animation.repeatCount = repeatCount;
//    animation.delegate = self;
    
    return animation;
    
}

10.判断当前的控制器是哪个

#pragma MARK: 点击通知栏的时候 判断当前的控制器是哪个
-(UIViewController*)atPersentViewController:(UIViewController*)vc {
    
    if (vc.presentedViewController) {
        return [self atPersentViewController:vc.presentedViewController];
    } else if ([vc isKindOfClass:[UISplitViewController class]]) {

        UISplitViewController* svc = (UISplitViewController*) vc;
        if (svc.viewControllers.count > 0)
            return [self atPersentViewController:svc.viewControllers.lastObject];
        else
            return vc;
        
    } else if ([vc isKindOfClass:[UINavigationController class]]) {
        
        UINavigationController* svc = (UINavigationController*) vc;
        if (svc.viewControllers.count > 0)
            return [self atPersentViewController:svc.topViewController];
        else
            return vc;
        
    } else if ([vc isKindOfClass:[UITabBarController class]]) {
        
        UITabBarController* svc = (UITabBarController*) vc;
        if (svc.viewControllers.count > 0)
            return [self atPersentViewController:svc.selectedViewController];
        else
            return vc;
        
    } else {
        
        return vc;

    }
}

-(UIViewController*) currentViewController {
    
    UIViewController* viewController = [UIApplication sharedApplication].keyWindow.rootViewController;
    return [self atPersentViewController:viewController];
    
}

11.生成二维码

- (CIImage *)creatQRcodeWithUrlstring:(NSString *)urlString{
    
    // 1.实例化二维码滤镜
    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
    // 2.恢复滤镜的默认属性 (因为滤镜有可能保存上一次的属性)
    [filter setDefaults];
    // 3.将字符串转换成NSdata
    NSData *data  = [urlString dataUsingEncoding:NSUTF8StringEncoding];
    // 4.通过KVO设置滤镜, 传入data, 将来滤镜就知道要通过传入的数据生成二维码
    [filter setValue:data forKey:@"inputMessage"];
    //设置二维码的纠错水平，越高纠错水平越高，可以污损的范围越大
    /*
        * L: 7%
        * M: 15%
        * Q: 25%
        * H: 30%
        */
    [filter setValue:@"H" forKey:@"inputCorrectionLevel"];
    // 5.生成二维码
    CIImage *outputImage = [filter outputImage];
    return outputImage;
}
- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size
{
    CGRect extent = CGRectIntegral(image.extent);
    CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));
    
    // 1.创建bitmap;
    size_t width = CGRectGetWidth(extent) * scale;
    size_t height = CGRectGetHeight(extent) * scale;
    CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();
    CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);
    CIContext *context = [CIContext contextWithOptions:nil];
    CGImageRef bitmapImage = [context createCGImage:image fromRect:extent];
    CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
    CGContextScaleCTM(bitmapRef, scale, scale);
    CGContextDrawImage(bitmapRef, extent, bitmapImage);
    
    // 2.保存bitmap到图片
    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
    CGContextRelease(bitmapRef);
    CGImageRelease(bitmapImage);
    return [UIImage imageWithCGImage:scaledImage];
}

12 UITextView字数限制

描述: textView输入文本有字数限制36,
直接用textView.text = [textview.text substringToIndex:36]来截取到100前的字符,
会将键盘预输入的拼音都算入其中,
导致到了36时,
textView的text直接变成键盘中预输入的拼音

//代理方法
-(void)textViewDidChange:(UITextView *)textView{

    NSString  *nsTextContent = textView.text;
    NSInteger existTextNum = nsTextContent.length;

       if (textView.markedTextRange == nil) {
           // 没有预输入文字
           if (existTextNum > 36){
               //截取到最大位置的字符
               NSString *s = [nsTextContent substringToIndex:36];
               [textView setText:s];
           }
       }
    
}