oc一些琐碎的API

1.关于图片加圆角

   //创建image的圆角
    self.heroImage.layer.cornerRadius=self.heroImage.bounds.size.height*0.4;
    //设置边框
    self.heroImage.layer.borderWidth=3;
    //设置颜色
    self.heroImage.layer.borderColor=[UIColororangeColor].CGColor;
    //剪切
    self.heroImage.layer.masksToBounds=YES;
    //填图

   self.heroImage.image=hero.image;

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2.隐藏状态栏

- (BOOL)prefersStatusBarHidden 隐藏状态栏

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3.粘贴板

//把内容保存到剪贴板中，剪贴板是全局的

        [UIPasteboardgeneralPasteboard].strings= @[heroa.icon,heroa.name,heroa.intro];

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4.让数组中的每个元素都执行某种方法

 /* - (void)makeObjectsPerformSelector:(SEL)aSelector;
        - (void)makeObjectsPerformSelector:(SEL)aSelector withObject:(id)argument;
        让集合里面的所有元素都执行aSelector这个方法*/

        //给数组里的每个成员发消息，调用方法
        [arr makeObjectsPerformSelector:@selector(study)];
        NSLog(@"————————————————————————");

        [armakeObjectsPerformSelector:@selector(run:)withObject:@"大家都在跑步"];

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5.获取字符串

       // 从文件中读取字符串
          // 用来保存错误的信息
        NSError *error = nil;
        NSString *str3 = [NSString stringWithContentsOfFile:@"/Users/xiaoguo/Desktop/test.txt"encoding:NSUTF8StringEncodingerror:&error];
       
        if (error){
            NSLog(@"读取失败，错误对的原因是：%@",[errorlocalizedDescription]);
        }else{

           NSLog(@"读取成功，文件的内容是：\n%@",str3);

        }

       
        

       //从URL中读取文件
       
        //NSURL *url1 = [NSURL fileURLWithPath:@"/Users/xiaoguo/Desktop/test.txt"];
         NSURL *url = [NSURL URLWithString:@"file:///Users/xiaoguo/Desktop/test.txt"];
        NSString *str4 = [NSString stringWithContentsOfURL:url encoding:NSUTF8StringEncodingerror:&error];

       NSLog(@"str4 = %@",str4);

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6.拼接文件路劲

 
       /* - (NSString *)stringByAppendingPathComponent:(NSString *)str;

       在路径的后面拼接一个目录

7.屏幕的变换因子

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8.buttton图片移动

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9.桥接

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10.不停的调用一个方法  定时器

nstimer

   NSTimer *timer =[ NSTimer timerWithTimeInterval:2target:selfselector:@selector(changeColor)userInfo:nilrepeats:YES];
    self.timer=timer;

    [[NSRunLoopmainRunLoop]addTimer:timerforMode:NSDefaultRunLoopMode];

CaDisplayLink

 self.link= [CADisplayLinkdisplayLinkWithTarget:selfselector:@selector(changeColor)];

    [self.linkaddToRunLoop:[NSRunLoopmainRunLoop]forMode:NSDefaultRunLoopMode];

 timestamp 

 duration 持续时间

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11

取消滑块

   //取消滑块
    self.tableView.showsHorizontalScrollIndicator=YES;

   self.tableView.showsVerticalScrollIndicator=YES;

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12 关于navgationbar item的设置

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13小图坐标转大图坐标

  //获取view
//    SXPView *view=(SXPView *)self.view;
//    [gravity setAction:^{
//        view.startPoint=point;
//        CGPoint myPoint=CGPointZero;
//        //转换为当前view的界面中的点
//        CGPoint endPoint=[self.view convertPoint:myPoint fromView:self.myView];
//        view.endPoint=endPoint;

//    }];

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Attributes 属性参数

NSFontAttributeName 先记住这个

13.关于CGRect;

用字符串打印是:    NSLog(@"%@",NSStringFromCGRect(rect));

获取最大最小是  CGRectGetMAX/min

14.一个大坑,如果设置UIView的分类情况下(分类的作用是获取x.y.center).如果一个空间的size设置在x 和centerx后面,就会出现诡异的现象
先设置size  在设置x 和y 值