UITextField设置无法输入空格

1.在UITextFieldDelegate的代理方法中设置过滤空格

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {        NSString *textPsw = [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];    if ([textPsw length] == 0) {        return NO;    }    return YES;}

此时虽然不能输入空格，但是出现点击删除键却无法删除的问题，解决如下：

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {        NSString *textPsw = [string stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];    if (range.length == 1 && textPsw.length == 0) {        return YES;    }    if ([textPsw length] == 0) {        return NO;    }    return YES;}