线程--延迟

一提到延迟首先想到的是Sleep

[NSThread sleepForTimeInterval:10];

这只是等待十秒之后在执行

这里说的是

dispatch_after是延迟提交，不是延迟运行

先看看官方文档的说明：

Enqueue a block for execution at the specified time.

Enqueue，就是入队，指的就是将一个Block在特定的延时以后，加入到指定的队列中，不是在特定的时间后立即运行！。

[UILabel showStats:@"存储成功" atView:self.view];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        [self.navigationController popViewControllerAnimated:YES];
});

 这两句代码执行之后的效果如下

 uilabel 调用方法的延展

UILabel+Extension.h

#import <UIKit/UIKit.h>

@interface UILabel (Extension)

+ (UILabel *)labelWithFont:(UIFont *)font
                 textColor:(UIColor *)textColor
             numberOfLines:(NSInteger)lines
             textAlignment:(NSTextAlignment)textAlignment;


/**
 *  自己粗略做的一个指示器=。=
 *
 *  @param stats 提示内容
 *  @param view  添加到view上
 */
+ (void)showStats:(NSString *)stats atView:(UIView *)view;

/**
 *  快速设置富文本
 *
 *  @param string 需要设置的字符串
 *  @param range  需要设置的范围（范围文字颜色显示为下厨房橘红色）
 */
- (void)setAttributeTextWithString:(NSString *)string range:(NSRange)range;
@end

 UILabel+Extension.m

#import "UILabel+Extension.h"

@implementation UILabel (Extension)

+ (UILabel *)labelWithFont:(UIFont *)font
                 textColor:(UIColor *)textColor
             numberOfLines:(NSInteger)lines
             textAlignment:(NSTextAlignment)textAlignment {
    UILabel *label = [[UILabel alloc] init];
    label.font = font;
    label.textColor = textColor;
    label.numberOfLines = lines;
    label.textAlignment = textAlignment;
    return label;
}


+ (void)showStats:(NSString *)stats atView:(UIView *)view {
    
    UILabel *message = [[UILabel alloc] init];
    message.layer.cornerRadius = 10;
    message.clipsToBounds = YES;
    message.backgroundColor = RGBA(0, 0, 0, 0.8);
    message.numberOfLines = 0;
    message.font = [UIFont systemFontOfSize:15];
    message.textColor = XCFLabelColorWhite;
    message.textAlignment = NSTextAlignmentCenter;
    message.alpha = 0;
    
    message.text = stats;
    CGSize size = [stats boundingRectWithSize:CGSizeMake(MAXFLOAT, 50)
                                     options:NSStringDrawingUsesLineFragmentOrigin
                                  attributes:@{NSFontAttributeName : [UIFont systemFontOfSize:15]}
                                     context:nil].size;
    message.frame = CGRectMake(0, 0, size.width + 20, size.height + 10);
    message.center = view.center;
    [view addSubview:message];
    
    [UIView animateWithDuration:1.5 animations:^{
        message.alpha = 1;
    } completion:^(BOOL finished) {
        [UIView animateWithDuration:2 animations:^{
            message.alpha = 0;
        } completion:^(BOOL finished) {
            [message removeFromSuperview];
            
        }];
    }];
}


- (void)setAttributeTextWithString:(NSString *)string range:(NSRange)range {
    NSMutableAttributedString *attrsString = [[NSMutableAttributedString alloc] initWithString:string];
    [attrsString addAttribute:NSForegroundColorAttributeName value:XCFThemeColor range:range];
    self.attributedText = attrsString;
}

@end