又不知道怎么开头，还是直接上需求吧。简单粗暴，就是按照UI的图做就是咯~~~

需求.png

低.png

中.png

高.png

拿到这个需求的时候，问到底什么情况是低什么是中什么是高，结果告诉我自己解决，我特么不是设计啊，我怎么知道，然后自己默默的去网上搜了了一堆判断，然后来解决吧。

      #pragma mark - 判断密码强度函数
    /*
   声明：包含大写/小写/数字/特殊字符
   两种以下密码强度低
   两种密码强度中
   大于两种密码强度高
   密码强度标准根据需要随时调整
   */
  //判断是否包含
  + (BOOL) judgeRange:(NSArray*) _termArray Password:(NSString*) _password
  {
NSRange range;
BOOL result =NO;
for(int i=0; i<[_termArray count]; i++)
{
    range = [_password rangeOfString:[_termArray objectAtIndex:i]];
    if(range.location != NSNotFound)
    {
        result =YES;
    }
}
return result;
}

  //条件
  + (NSString*) judgePasswordStrength:(NSString*) _password
{
NSMutableArray* resultArray = [[NSMutableArray alloc] init];

NSArray* termArray1 = [[NSArray alloc] initWithObjects:@"a", @"b", @"c", @"d", @"e", @"f", @"g", @"h", @"i", @"j", @"k", @"l", @"m", @"n", @"o", @"p", @"q", @"r", @"s", @"t", @"u", @"v", @"w", @"x", @"y", @"z", nil];
NSArray* termArray2 = [[NSArray alloc] initWithObjects:@"1", @"2", @"3", @"4", @"5", @"6", @"7", @"8", @"9", @"0", nil];
NSArray* termArray3 = [[NSArray alloc] initWithObjects:@"A", @"B", @"C", @"D", @"E", @"F", @"G", @"H", @"I", @"J", @"K", @"L", @"M", @"N", @"O", @"P", @"Q", @"R", @"S", @"T", @"U", @"V", @"W", @"X", @"Y", @"Z", nil];
NSArray* termArray4 = [[NSArray alloc] initWithObjects:@"~",@"`",@"@",@"#",@"$",@"%",@"^",@"&",@"*",@"(",@")",@"-",@"_",@"+",@"=",@"{",@"}",@"[",@"]",@"|",@":",@";",@"“",@"'",@"‘",@"<",@",",@".",@">",@"?",@"/",@"、", nil];
NSString* result1 = [NSString stringWithFormat:@"%d",[self judgeRange:termArray1 Password:_password]];
NSString* result2 = [NSString stringWithFormat:@"%d",[self judgeRange:termArray2 Password:_password]];
NSString* result3 = [NSString stringWithFormat:@"%d",[self judgeRange:termArray3 Password:_password]];
NSString* result4 = [NSString stringWithFormat:@"%d",[self judgeRange:termArray4 Password:_password]];

[resultArray addObject:[NSString stringWithFormat:@"%@",result1]];
[resultArray addObject:[NSString stringWithFormat:@"%@",result2]];
[resultArray addObject:[NSString stringWithFormat:@"%@",result3]];
[resultArray addObject:[NSString stringWithFormat:@"%@",result4]];
int intResult=0;
for (int j=0; j<[resultArray count]; j++)
{
    if ([[resultArray objectAtIndex:j] isEqualToString:@"1"])
    {
        intResult++;
    }
}
NSString* resultString = [[NSString alloc] init];
if (intResult < 2)
{
    resultString = @"0";
}
else if (intResult == 2&&[_password length]>=6)
{
    resultString = @"1";
}
if (intResult > 2&&[_password length]>=6)
{
    resultString = @"2";
}
return resultString;
}

有了这个好像已经成功了一半，但是怎么让它显示呢，那么

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSString *resultString = [[NSString alloc]init];
if ([string isEqualToString:@""]) { //按了删除键
    resultString = [textField.text substringToIndex:textField.text.length - 1];
} else {
    resultString = [NSString stringWithFormat:@"%@%@",textField.text,string];
}
NSInteger result = [[NSString judgePasswordStrength:resultString] integerValue];
switch (result) {
    case 0:
        _lowLabel.textColor = xxx;
        _middleLabel.textColor =  xxx;
        _highLabel.textColor =  xxx;
        break;
    case 1:
        _middleLabel.textColor =  xxx;
        _lowLabel.textColor = xxx;
        _highLabel.textColor =  xxx;
        break;
    case 2:
        _highLabel.textColor = xxx;
        _lowLabel.textColor =  xxx;
        _middleLabel.textColor =  xxx;
        break;
    default:
        break;
}
return YES;
}

代码很简单没什么解释的，嘻嘻嘻，有需要的可以参考参考，睡觉了。