我们会经常用到限制字母与数字输入
#define kAlphaNum @"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
#pragma mark -textFieldDelegate
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
// 限制只能输入 数字 和字母
NSCharacterSet *cs = [[NSCharacterSet characterSetWithCharactersInString:kAlphaNum] invertedSet];
NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];
return [string isEqualToString:filtered];
}
