记录一些开发中常用的方法和技巧

判断字符串是否是中文的代码

- (BOOL)isChinese:(NSString *)text

{

    NSString *temp =@"[\u4e00-\u9fa5]";

    NSRange range = [textrangeOfString:tempoptions:NSRegularExpressionSearch];

    

    return range.location !=NSNotFound ?YES :NO;

}

iOS 隐藏/去掉 导航栏返回按钮中的文字

[[UIBarButtonItemappearance]setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -60)

                                                        forBarMetrics:UIBarMetricsDefault];

iOSMD5加密数据方法

+ (NSString *)md5StringFromString:(NSString *)string {

    if(string ==nil || [stringlength] == 0)

        returnnil;

    const char *value = [stringUTF8String];

    unsigned char outputBuffer[CC_MD5_DIGEST_LENGTH];

    CC_MD5(value, (CC_LONG)strlen(value), outputBuffer);

    NSMutableString *outputString = [[NSMutableStringalloc]initWithCapacity:CC_MD5_DIGEST_LENGTH *2];

    for(NSInteger count =0; count <CC_MD5_DIGEST_LENGTH; count++){

        [outputString appendFormat:@"%02x",outputBuffer[count]];

    }

    return outputString;

}

iOS内获取当前APP版本号

+ (NSString *)appVersionString {

    return [[[NSBundlemainBundle]infoDictionary] objectForKey:@"CFBundleShortVersionString"];

}

 

- (void)initUserInterface
{
  UILabel *label = [[UILabel alloc]init];
  label.numberOfLines = 0; // 需要把显示行数设置成无限制
  label.font = [UIFont systemFontOfSize:15];
  label.textAlignment = NSTextAlignmentCenter;
  label.text = @"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
  CGSize size =  [self sizeWithString:label.text font:label.font];
  label.bounds = CGRectMake(0, 0, size.width, size.height);
  label.center = self.view.center;
  [self.view addSubview:label];
  
}
// 定义成方法方便多个label调用 增加代码的复用性
- (CGSize)sizeWithString:(NSString *)string font:(UIFont *)font
{
  CGRect rect = [string boundingRectWithSize:CGSizeMake(320, 8000)//限制最大的宽度和高度
                     options:NSStringDrawingTruncatesLastVisibleLine | NSStringDrawingUsesFontLeading  |NSStringDrawingUsesLineFragmentOrigin//采用换行模式
                  attributes:@{NSFontAttributeName: font}//传人的字体字典
                     context:nil];
  
  return rect.size;
}

//  在TableView 里的子视图固定  不随滑动而改变

    myView = [[UIView alloc] initWithFrame:CGRectMake(10, 100, 150, 30)];

    myView.backgroundColor = [UIColor redColor];

    [self.tableView addSubview:myView];

在代理方法里设置自身的y值+contentOffset.y

-(void)scrollViewDidScroll:(UIScrollView *)scrollView

{

    myView.frame = CGRectMake(myView.frame.origin.x, 100+self.tableView.contentOffset.y , myView.frame.size.width, myView.frame.size.height);

}