（iOS开发）判断字符串中是否含有中文，字母

for (int i=0; i<strFrom.length; i++) {    NSRange range =NSMakeRange(i, 1);    NSString * strFromSubStr=[strFrom substringWithRange:range];    const char * cStringFromstr=[strFromSubStr UTF8String];        if (strlen(cStringFromstr)==3) {        //汉字    }else if (strlen(cStringFromstr)==1)    {        //字母    }}