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;
}
}