请问如何限制除了点和下划线的特殊字符
怎么限制UITextField 中的特殊字符？只保留点和下划线。我用了下面的代码，但是没有反应：
#define ACCEPTABLE_CHARECTERS @" ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_."
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
NSCharacterSet *acceptedInput = [NSCharacterSet characterSetWithCharactersInString:ACCEPTABLE_CHARECTERS];
if (![[string componentsSeparatedByCharactersInSet:acceptedInput] count] > 1){
NSLog(@"not allowed");
return NO;
}
else{
return YES;
}
}
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不知道怎么回答好...因为方法太多了...
方法一: 使用scaner(如果你坚持要自定义accetpable的字符)NSString *yourString = @"tBe47s_-#h54df"; NSMutableString *resultString = [NSMutableString stringWithCapacity:yourString.length]; NSScanner *scanner = [NSScanner scannerWithString:yourString]; NSCharacterSet *charSet = [NSCharacterSet characterSetWithCharactersInString:@"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_."]; while ([scanner isAtEnd] == NO) { NSString *buffer; if ([scanner scanCharactersFromSet:charSet intoString:&buffer]) [resultString appendString:buffer]; else [scanner setScanLocation:([scanner scanLocation] + 1)]; } NSLog(@"result: %@", resultString);方法二:正则表达式(iOS4.0以后适用,4之前要用第三方库)
NSString *yourString = @"tBe%#&4.7s_-#h5S4df"; NSError *error = NULL; NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"([^A-Za-z0-9_.])" options:0 error:&error]; NSString *resString = [regex stringByReplacingMatchesInString:yourString options:0 range:NSMakeRange(0, yourString.length) withTemplate:@""]; NSLog(@"result: %@", resString);2019-07-17 19:15:04赞同 展开评论
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