iOS 关于NSString的一些方法

在项目中整理的一些关于字符串应用方法，可以全部封装在一个类里面进行调用，会不断更新添加：

1.数字转换成对应的中文数字（项目中课程分级目录的章节号用到）

摘自：http://blog.csdn.net/it_ds/article/details/47128563

+(NSString *)translation:(NSString *)arebic
{   NSString *str = arebic;
    NSArray *arabic_numerals = @[@"1",@"2",@"3",@"4",@"5",@"6",@"7",@"8",@"9",@"0"];
    NSArray *chinese_numerals = @[@"一",@"二",@"三",@"四",@"五",@"六",@"七",@"八",@"九",@"零"];
    NSArray *digits = @[@"个",@"十",@"百",@"千",@"万",@"十",@"百",@"千",@"亿",@"十",@"百",@"千",@"兆"];
    NSDictionary *dictionary = [NSDictionary dictionaryWithObjects:chinese_numerals forKeys:arabic_numerals];

    NSMutableArray *sums = [NSMutableArray array];
    for (int i = 0; i < str.length; i ++) {
        NSString *substr = [str substringWithRange:NSMakeRange(i, 1)];
        NSString *a = [dictionary objectForKey:substr];
        NSString *b = digits[str.length -i-1];
        NSString *sum = [a stringByAppendingString:b];
        if ([a isEqualToString:chinese_numerals[9]])
        {
            if([b isEqualToString:digits[4]] || [b isEqualToString:digits[8]])
            {
                sum = b;
                if ([[sums lastObject] isEqualToString:chinese_numerals[9]])
                {
                    [sums removeLastObject];
                }
            }else
            {
                sum = chinese_numerals[9];
            }

            if ([[sums lastObject] isEqualToString:sum])
            {
                continue;
            }
        }
        [sums addObject:sum];
    }
    NSString *sumStr = [sums  componentsJoinedByString:@""];
    NSString *chinese = [sumStr substringToIndex:sumStr.length-1];
    NSLog(@"%@",str);
    NSLog(@"%@",chinese);
    return chinese;
}

2.判断是否含有中文（视频网址判断是否需要转码）

+(BOOL)isChinese:(NSString *)str{

    for (int i=0; i<str.length; ++i)
    {
        NSRange range = NSMakeRange(i, 1);
        NSString *subString = [str substringWithRange:range];
        const char *cString = [subString UTF8String];
        if (strlen(cString) == 3)
        {
            return YES;
        }
    }
    return NO;
}

3.去除特殊字符（去除时间戳中的”/“时用到）

+(NSString *) stringDeleteString:(NSString *)str
{
    NSMutableString *str1 = [NSMutableString stringWithString:str];
    for (int i = 0; i < str1.length; i++) {
        unichar c = [str1 characterAtIndex:i];
        NSRange range = NSMakeRange(i, 1);
        if ( c == '/' || c == '-' || c == '.' || c == ',' || c == '(' || c == ')') { //此处可以是任何字符
            [str1 deleteCharactersInRange:range];
            --i;
        }
    }
    NSString *newstr = [NSString stringWithString:str1];
    return newstr;
}

4.特殊字符转义（textView往接口传入含”&“的内容不能成功 因为接口参数以”&“开头 解决方式是移动端将输入内容先转义 然后后台再转一次）

+(NSString *)replaceMyString:(NSString *)textStr{

//    NSString *inputString = [[NSString alloc]init];
    NSString *inputString = textStr;
    //inputString = [inputString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
    inputString = [inputString stringByReplacingOccurrencesOfString:@"&" withString:@"&"];
    inputString = [inputString stringByReplacingOccurrencesOfString:@"<" withString:@"<"];
    inputString = [inputString stringByReplacingOccurrencesOfString:@">" withString:@">"];
    inputString = [inputString stringByReplacingOccurrencesOfString:@" " withString:@" "];
    inputString = [inputString stringByReplacingOccurrencesOfString:@"\'" withString:@"'"];
    inputString = [inputString stringByReplacingOccurrencesOfString:@"\"" withString:@"""];
    inputString = [inputString stringByReplacingOccurrencesOfString:@"\r" withString:@""];
    inputString = [inputString stringByReplacingOccurrencesOfString:@"\n" withString:@"<br />"];

    return inputString;
}

5.将秒数转换成时、分（接口返回的时长都是秒单位 如3600 需要转成小时和分钟的样式时用到）

//修改时分的方法
+(NSString *)TimeformatFromSeconds:(int)seconds
{
    if (seconds > 60 ) {
        NSString *str_hour = [NSString stringWithFormat:@"%d",seconds/3600];
        NSString *str_minute = [NSString stringWithFormat:@"%d",(seconds%3600)/60];
        if([str_hour isEqualToString:@"0"] )
        {
            int minutInt = (seconds%3600)%60;
            if (minutInt != 0) {
                NSString *format_time = [NSString stringWithFormat:@"%d",[str_minute intValue]+1];
                return format_time;
            }else{
                NSString *format_time = [NSString stringWithFormat:@"%@",str_minute];
                return format_time;
            }

        }else
        {
            int minutInt = (seconds%3600)%60;
            if (minutInt != 0) {
                NSString *format_time = [NSString stringWithFormat:@"%@时%d",str_hour,[str_minute intValue]+1];
                return format_time;
            }else{
                NSString *format_time = [NSString stringWithFormat:@"%@时%@",str_hour,str_minute];
                return format_time;
            }
        }
    }else if(seconds == 0)
    {
        return @"0";
    }
    else{
        return @"1";
    }
}

6.获取文件的大小（下载课程视频获取大小时用到）

//返回文件大小的方法
+(NSString *)getFileSizeString:(CGFloat)size
{
    if (size>1024*1024*1024){
        return [NSString stringWithFormat:@"%.1fG",size/1024/1024/1024];//大于1G，则转化成G单位的字符串
    }
    else if(size<1024*1024*1024&&size>=1024*1024)//大于1M，则转化成M单位的字符串
    {
        return [NSString stringWithFormat:@"%.1fM",size/1024/1024];
    }
    else if(size>=1024&&size<1024*1024) //不到1M,但是超过了1KB，则转化成KB单位
    {
        return [NSString stringWithFormat:@"%.1fK",size/1024];
    }
    else//剩下的都是小于1K的，则转化成B单位
    {
        return [NSString stringWithFormat:@"%.1fB",size];
    }
}

7.计算时间差（事前保存的时间与当前时间差 用于课程更新时间的显示）

+(NSString *)compareCurrentTime:(NSDate*)compareDate
{
    NSTimeInterval  timeInterval = [compareDate timeIntervalSinceNow];
    timeInterval = -timeInterval;
    long temp = ;
    NSString *result;
    NSLog(@"timeInterval：%f ",timeInterval);
    if (timeInterval < ) {
        result = [NSString stringWithFormat:@"刚刚"];
    }
    else if((temp = timeInterval/) <){
        result = [NSString stringWithFormat:@"%ld分前",temp];
    }
    else if((temp = temp/) <){
        result = [NSString stringWithFormat:@"%ld小前",temp];
    }
    else if((temp = temp/) <){

        result = [NSString stringWithFormat:@"%ld天前",temp];
    }
    else if((temp = temp/) <){
        result = [NSString stringWithFormat:@"%ld月前",temp];
    }
    else{
        temp = temp/;
        result = [NSString stringWithFormat:@"%ld年前",temp];
    }
    return  result;

}

8.字符串转进制 （给后台提交数据时有用到）

//字符串转16进制
+(NSString *)unicoStr:(NSString *)text
{
    NSString *hexstr = @"";

    for (int i=0;i< [text length];i++)
    {
        hexstr = [hexstr stringByAppendingFormat:@"%@",[NSString stringWithFormat:@"0x%1X ",[text characterAtIndex:i]]];
    }
    return hexstr;
}
//字符串转8进制
+(NSString *)eightUnicoStr:(NSString *)text
{
    NSString *hexstr = @"";
//    int slen = strlen([text UTF8String]);
    for (int i = 0; i < text.length; i++)
    {
        //fffffff0 去除前面六个F & 0xFF
        hexstr = [hexstr stringByAppendingFormat:@"%@",[NSString stringWithFormat:@"0x%X ",[text UTF8String][i] & 0xFF ]];
    }
    return hexstr;
}

8.字符串中的以另一种颜色标出个别文字，例如：已学：分钟

//字符串文字显示两种颜色
+(NSMutableAttributedString *)stringTwoColor:(NSString *)allStr changeColorStr:(NSString *)changeColorStr
{
    NSMutableAttributedString *inteMutStr = [[NSMutableAttributedString alloc] initWithString:allStr];

    NSRange orangeRange = NSMakeRange([[inteMutStr string] rangeOfString:changeColorStr].location, [[inteMutStr string] rangeOfString:changeColorStr].length);
    [inteMutStr addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:orangeRange];
    return inteMutStr;
}
调用的例子：
UILabel *myLable = [[UILabel alloc]initWithFrame:CGRectMake(100, 100, 200, 30)];
[self.view addSubview:myLable];
NSString *numStr = @"4";
NSString *inteStr = [NSString stringWithFormat:@"已学:%@分",numStr];
[myLable setAttributedText:[self stringTwoColor:inteStr changeColorStr:numStr]];
运行程序查看lable的文字，其中数字4会成红色