原文地址

讓label的文字內(nèi)容顯示在左上／右上／左下／右下／中心頂／中心底部

自定義UILabel
// 重寫label的textRectForBounds方法
- (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines {
    CGRect rect = [super textRectForBounds:bounds limitedToNumberOfLines:numberOfLines];
    switch (self.textAlignmentType) {
        case WZBTextAlignmentTypeLeftTop: {
            rect.origin = bounds.origin;
        }
            break;
        case WZBTextAlignmentTypeRightTop: {
            rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, bounds.origin.y);
        }
            break;
        case WZBTextAlignmentTypeLeftBottom: {
            rect.origin = CGPointMake(bounds.origin.x, CGRectGetMaxY(bounds) - rect.size.height);
        }
            break;
        case WZBTextAlignmentTypeRightBottom: {
            rect.origin = CGPointMake(CGRectGetMaxX(bounds) - rect.size.width, CGRectGetMaxY(bounds) - rect.size.height);
        }
            break;
        case WZBTextAlignmentTypeTopCenter: {
            rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - rect.origin.y);
        }
            break;
        case WZBTextAlignmentTypeBottomCenter: {
            rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, CGRectGetMaxY(bounds) - CGRectGetMaxY(bounds) - rect.size.height);
        }
            break;
        case WZBTextAlignmentTypeLeft: {
            rect.origin = CGPointMake(0, rect.origin.y);
        }
            break;
        case WZBTextAlignmentTypeRight: {
            rect.origin = CGPointMake(rect.origin.x, 0);
        }
            break;
        case WZBTextAlignmentTypeCenter: {
            rect.origin = CGPointMake((CGRectGetWidth(bounds) - CGRectGetWidth(rect)) / 2, (CGRectGetHeight(bounds) - CGRectGetHeight(rect)) / 2);
        }
            break;
        default:
            break;
    }
    return rect;
}
- (void)drawTextInRect:(CGRect)rect {
    CGRect textRect = [self textRectForBounds:rect limitedToNumberOfLines:self.numberOfLines];
    [super drawTextInRect:textRect];
}

1.禁止手機(jī)睡眠

[UIApplication sharedApplication].idleTimerDisabled = YES;

KVO監(jiān)聽某個對象的屬性

    
// 添加監(jiān)聽者
[self addObserver:self forKeyPath:property options:NSKeyValueObservingOptionNew context:nil];
 
// 當(dāng)監(jiān)聽的屬性值變化的時(shí)候會來到這個方法
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
    if ([keyPath isEqualToString:@"property"]) {
       [self textViewTextChange];
       } else {
     }
}

2.隱藏某行cell

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
// 如果是你需要隱藏的那一行，返回高度為0
    if(indexPath.row == YouWantToHideRow)
        return 0; 
    return 44;
}
 
// 然后再你需要隱藏cell的時(shí)候調(diào)用
[self.tableView beginUpdates];
[self.tableView endUpdates];

15、跳進(jìn)app權(quán)限設(shè)置

// 跳進(jìn)app設(shè)置
            if (UIApplicationOpenSettingsURLString != NULL) {
                NSURL *url = [NSURL URLWithString:UIApplicationOpenSettingsURLString];
                [[UIApplication sharedApplication] openURL:url];
            }
        }

16、給一個view截圖

UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, 0.0);
    [view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

17、開發(fā)中如果要動態(tài)修改tableView的tableHeaderView或者tableFooterView的高度，需要給tableView重新設(shè)置，而不是直接更改高度。正確的做法是重新設(shè)置一下tableView.tableFooterView = 更改過高度的view。為什么？其實(shí)在iOS8以上直接改高度是沒有問題的，在iOS8中出現(xiàn)了contentSize不準(zhǔn)確的問題，這是解決辦法。

20、設(shè)置navigationBar上的title顏色和大小

    [self.navigationController.navigationBar setTitleTextAttributes:@{NSForegroundColorAttributeName : [UIColor youColor], NSFontAttributeName : [UIFont systemFontOfSize:15]}]

22、view設(shè)置圓角

#define ViewBorderRadius(View, Radius, Width, Color)\
\
[View.layer setCornerRadius:(Radius)];\
[View.layer setMasksToBounds:YES];\
[View.layer setBorderWidth:(Width)];\
[View.layer setBorderColor:[Color CGColor]] // view圓角

26、獲取圖片資源

#define GetImage(imageName) [UIImage imageNamed:[NSString stringWithFormat:@"%@",imageName]]

36、通知

#define NOTIF_ADD(n, f)     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(f) name:n object:nil]
#define NOTIF_POST(n, o)    [[NSNotificationCenter defaultCenter] postNotificationName:n object:o]
#define NOTIF_REMV()        [[NSNotificationCenter defaultCenter] removeObserver:self]

37、隨機(jī)顏色

+ (UIColor *)RandomColor {
    NSInteger aRedValue = arc4random() % 255;
    NSInteger aGreenValue = arc4random() % 255;
    NSInteger aBlueValue = arc4random() % 255;
    UIColor *randColor = [UIColor colorWithRed:aRedValue / 255.0f green:aGreenValue / 255.0f blue:aBlueValue / 255.0f alpha:1.0f];
    return randColor;
}

39、修改textField的placeholder的字體顏色、大小

[textField setValue:[UIColor redColor] forKeyPath:@"_placeholderLabel.textColor"];
[textField setValue:[UIFont boldSystemFontOfSize:16] forKeyPath:@"_placeholderLabel.font"];

42、獲取app緩存大小

- (CGFloat)getCachSize {
 
    NSUInteger imageCacheSize = [[SDImageCache sharedImageCache] getSize];
    //獲取自定義緩存大小
    //用枚舉器遍歷 一個文件夾的內(nèi)容
    //1.獲取 文件夾枚舉器
    NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];
    NSDirectoryEnumerator *enumerator = [[NSFileManager defaultManager] enumeratorAtPath:myCachePath];
    __block NSUInteger count = 0;
    //2.遍歷
    for (NSString *fileName in enumerator) {
        NSString *path = [myCachePath stringByAppendingPathComponent:fileName];
        NSDictionary *fileDict = [[NSFileManager defaultManager] attributesOfItemAtPath:path error:nil];
        count += fileDict.fileSize;//自定義所有緩存大小
    }
    // 得到是字節(jié)  轉(zhuǎn)化為M
    CGFloat totalSize = ((CGFloat)imageCacheSize+count)/1024/1024;
    return totalSize;
}

43、清理app緩存

- (void)handleClearView {
    //刪除兩部分
    //1.刪除 sd 圖片緩存
    //先清除內(nèi)存中的圖片緩存
    [[SDImageCache sharedImageCache] clearMemory];
    //清除磁盤的緩存
    [[SDImageCache sharedImageCache] clearDisk];
    //2.刪除自己緩存
    NSString *myCachePath = [NSHomeDirectory() stringByAppendingPathComponent:@"Library/Caches"];
    [[NSFileManager defaultManager] removeItemAtPath:myCachePath error:nil];
}

47、幾個常用權(quán)限判斷

 if ([CLLocationManager authorizationStatus] ==kCLAuthorizationStatusDenied) {
        NSLog(@"沒有定位權(quán)限");
    }
    AVAuthorizationStatus statusVideo = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
    if (statusVideo == AVAuthorizationStatusDenied) {
        NSLog(@"沒有攝像頭權(quán)限");
    }
    //是否有麥克風(fēng)權(quán)限
    AVAuthorizationStatus statusAudio = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeAudio];
    if (statusAudio == AVAuthorizationStatusDenied) {
        NSLog(@"沒有錄音權(quán)限");
    }
    [PHPhotoLibrary requestAuthorization:^(PHAuthorizationStatus status) {
        if (status == PHAuthorizationStatusDenied) {
            NSLog(@"沒有相冊權(quán)限");
        }
    }];

49、長按復(fù)制功能

- (void)viewDidLoad
{
    [self.view addGestureRecognizer:[[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(pasteBoard:)]];
}
- (void)pasteBoard:(UILongPressGestureRecognizer *)longPress {
    if (longPress.state == UIGestureRecognizerStateBegan) {
        UIPasteboard *pasteboard = [UIPasteboard generalPasteboard];
        pasteboard.string = @"需要復(fù)制的文本";
    }
}

55、image圓角

- (UIImage *)circleImage
{
    // NO代表透明
    UIGraphicsBeginImageContextWithOptions(self.size, NO, 1);
    // 獲得上下文
    CGContextRef ctx = UIGraphicsGetCurrentContext();
    // 添加一個圓
    CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
    // 方形變圓形
    CGContextAddEllipseInRect(ctx, rect);
    // 裁剪
    CGContextClip(ctx);
    // 將圖片畫上去
    [self drawInRect:rect];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

image拉伸

+ (UIImage *)resizableImage:(NSString *)imageName
{
    UIImage *image = [UIImage imageNamed:imageName];
    CGFloat imageW = image.size.width;
    CGFloat imageH = image.size.height;
    return [image resizableImageWithCapInsets:UIEdgeInsetsMake(imageH * 0.5, imageW * 0.5, imageH * 0.5, imageW * 0.5) resizingMode:UIImageResizingModeStretch];
}

57、JSON字符串轉(zhuǎn)字典

+ (NSDictionary *)parseJSONStringToNSDictionary:(NSString *)JSONString {
    NSData *JSONData = [JSONString dataUsingEncoding:NSUTF8StringEncoding];
    NSDictionary *responseJSON = [NSJSONSerialization JSONObjectWithData:JSONData options:NSJSONReadingMutableLeaves error:nil];
    return responseJSON;
}

61、拿到當(dāng)前正在顯示的控制器，不管是push進(jìn)去的，還是present進(jìn)去的都能拿到

- (UIViewController *)getVisibleViewControllerFrom:(UIViewController*)vc {
    if ([vc isKindOfClass:[UINavigationController class]]) {
        return [self getVisibleViewControllerFrom:[((UINavigationController*) vc) visibleViewController]];
    }else if ([vc isKindOfClass:[UITabBarController class]]){
        return [self getVisibleViewControllerFrom:[((UITabBarController*) vc) selectedViewController]];
    } else {
        if (vc.presentedViewController) {
            return [self getVisibleViewControllerFrom:vc.presentedViewController];
        } else {
            return vc;
        }
    }
}

71、根據(jù)bundle中的文件名讀取圖片

+ (UIImage *)imageWithFileName:(NSString *)name {
    NSString *extension = @"png";
 
    NSArray *components = [name componentsSeparatedByString:@"."];
    if ([components count] >= 2) {
        NSUInteger lastIndex = components.count - 1;
        extension = [components objectAtIndex:lastIndex];
 
        name = [name substringToIndex:(name.length-(extension.length+1))];
    }
 
    // 如果為Retina屏幕且存在對應(yīng)圖片，則返回Retina圖片，否則查找普通圖片
    if ([UIScreen mainScreen].scale == 2.0) {
        name = [name stringByAppendingString:@"@2x"];
 
        NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];
        if (path != nil) {
            return [UIImage imageWithContentsOfFile:path];
        }
    }
 
    if ([UIScreen mainScreen].scale == 3.0) {
        name = [name stringByAppendingString:@"@3x"];
 
        NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];
        if (path != nil) {
            return [UIImage imageWithContentsOfFile:path];
        }
    }
 
    NSString *path = [[NSBundle mainBundle] pathForResource:name ofType:extension];
    if (path) {
        return [UIImage imageWithContentsOfFile:path];
    }
 
    return nil;
}

73、根據(jù)bundle中的圖片名創(chuàng)建imageview

+ (id)imageViewWithImageNamed:(NSString*)imageName
{
    return [[UIImageView alloc] initWithImage:[UIImage imageNamed:imageName]];
}

cell去除選中效果
cell.selectionStyle = UITableViewCellSelectionStyleNone;

106、禁用系統(tǒng)滑動返回功能

- (void)viewDidAppear:(BOOL)animated
{
     [super viewDidAppear:animated];
if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = self;
    }
}
 
- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    if ([self.navigationController respondsToSelector:@selector(interactivePopGestureRecognizer)]) {self.navigationController.interactivePopGestureRecognizer.delegate = nil;
    }
}
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
     return NO;
}

109、UILabel設(shè)置內(nèi)邊距

子類化UILabel，重寫drawTextInRect方法
- (void)drawTextInRect:(CGRect)rect {
    // 邊距，上左下右
    UIEdgeInsets insets = {0, 5, 0, 5};
    [super drawTextInRect:UIEdgeInsetsInsetRect(rect, insets)];
}

117、將一個view放置在其兄弟視圖的最上面
1
    
[parentView bringSubviewToFront:yourView]

118、將一個view放置在其兄弟視圖的最下面
1
    
[parentView sendSubviewToBack:yourView]

122、搖一搖功能

1、打開搖一搖功能
    [UIApplication sharedApplication].applicationSupportsShakeToEdit = YES;
2、讓需要搖動的控制器成為第一響應(yīng)者
[self becomeFirstResponder];
3、實(shí)現(xiàn)以下方法
 
// 開始搖動
- (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event
// 取消搖動
- (void)motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event
// 搖動結(jié)束
- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event

132、設(shè)置tableView分割線顏色

[self.tableView setSeparatorColor:[UIColor myColor]];

135、tableViewCell分割線頂?shù)筋^

- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
    [cell setSeparatorInset:UIEdgeInsetsZero];
    [cell setLayoutMargins:UIEdgeInsetsZero];
    cell.preservesSuperviewLayoutMargins = NO;
}
 
- (void)viewDidLayoutSubviews {
    [self.tableView setSeparatorInset:UIEdgeInsetsZero];
    [self.tableView setLayoutMargins:UIEdgeInsetsZero];
}

139、在狀態(tài)欄增加網(wǎng)絡(luò)請求的菊花，類似safari加載網(wǎng)頁的時(shí)候狀態(tài)欄菊花

[UIApplication sharedApplication].networkActivityIndicatorVisible = YES;