ios - 检测是否在 UITextField 中插入了一个字符

Question

我有一个UITextField。我想检测某个字符是否被估算。这是我尝试过的”

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    for (int i = 0; i < [textField.text length]; i++) {
        if ([textField.text characterAtIndex:i] == @".") { // Error Here
            ...
        }
    }
}

我得到一个错误

Comparison between pointer and integer ('int' and 'NSStirng ')

所以我的做法显然是错误的。我的问题是如何解决这个问题？

Answer 1

你应该考虑使用:- (NSRange)rangeOfString:(NSString *)aString

更新

NSString *string1 = @"The quick brown fox jumped";
NSRange match;
match = [string1 rangeOfString: @"brown fox"];

if (match.location == NSNotFound)
          NSLog (@"Match not found");
else
          NSLog (@"match found");