iOS开发小技巧

不定期更新:有部分摘自其他博客,不一一列出出处,在此感谢作者

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• 使用MD5对NSData或者NSString加密

//需要引入此头文件来使用CC_MD5
#import <CommonCrypto/CommonDigest.h>

针对NSString的加密①

- (NSString *) md5:(NSString *) input{ 
  const char *cStr = [input UTF8String]; 
  unsigned char digest[CC_MD5_DIGEST_LENGTH]; 
  CC_MD5( cStr, strlen(cStr), digest );
  NSMutableString *output = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2]; 
  for(int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) [output appendFormat:@"%02x", digest[i]];
  return output;
}

针对NSString的加密②

- (NSString *)md5:(NSString *) input{ 
  const char *cStr = [input UTF8String]; 
  unsigned char result[CC_MD5_DIGEST_LENGTH]; 
  CC_MD5( cStr, (int)strlen(cStr), result ); 
  return [NSString stringWithFormat: @"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
            result[0], result[1], result[2], result[3],
            result[4], result[5], result[6], result[7],
            result[8], result[9], result[10], result[11],
            result[12], result[13], result[14], result[15]
            ];

}

针对NSData的加密

- (NSString*)md5:(NSData *)data
{
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5( data.bytes, (int)data.length, result ); 
    return [NSString stringWithFormat:
            @"%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
            result[0], result[1], result[2], result[3],
            result[4], result[5], result[6], result[7],
            result[8], result[9], result[10], result[11],
            result[12], result[13], result[14], result[15]
            ];  
}

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• 获取显示在屏幕上的所有cell

 self.tableView.visibleCells

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• 判断NSString中是否包含中文

-(BOOL)isChinese:(NSString *)str{
    NSString *match=@"(^[\u4e00-\u9fa5]+$)";
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"SELF matches %@", match];
    return [predicate evaluateWithObject:str];
}

• 去掉TableView未占满屏幕的空白行

self.tableView.tableFooterView = [UIView new];

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• iOS之UITextField 禁止粘贴

//方法1:重写下面方法
- (BOOL)canPerformAction:(SEL)action withSender:(id)sender
    {
        if (action == @selector(paste:))//禁止粘贴
            return NO;
        if (action == @selector(select:))// 禁止选择   
            return NO;   
        if (action == @selector(selectAll:))// 禁止全选   
            return NO;  
        return [super canPerformAction:action withSender:sender];
    }

//方法2:
-(BOOL)canPerformAction:(SEL)action withSender:(id)sender {
    UIMenuController *menuController = [UIMenuController sharedMenuController];
    if (menuController) {
        [UIMenuController sharedMenuController].menuVisible = NO;
    }
    return NO;
}

• Xcode7下将https请求改回http请求

//将下面代码加入info.plist文件
//info.plist->open as->source code
 <key>NSAppTransportSecurity</key>
 <dict>
  <key>NSAllowsArbitraryLoads</key>
  <true/>
 </dict>

• iOS9下将NSString转为UTF8

url = [url stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]];