如何启用关键'空间'＆amp;禁用密钥a-z时，在iPhone键盘上删除密钥

Question

我正在做一个自定义键盘，但我想使用一些默认键，如空格和删除键。这是我用来禁用密钥a-z的代码。

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
NSMutableString * character;
NSCharacterSet *disableLetters = [[NSCharacterSet characterSetWithCharactersInString:@"abcdefghijklmnopqrstuvwxyz"] invertedSet];

NSRange location = [character rangeOfCharacterFromSet:disableLetters];
return (location.location == NSNotFound);}

这是屏幕截图:(禁用其他键后我无法删除））

Answer 1

试试这个：

 - (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    //NSMutableString * character;
    NSCharacterSet *disableLetters = [[NSCharacterSet characterSetWithCharactersInString:@"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890_"] invertedSet];

    NSRange location = [string rangeOfCharacterFromSet:disableLetters];
    if(location.location != NSNotFound);
    {
       return YES;
    }
    else
    {
       return NO;
    }
 }

Answer 2

我修复了您的代码存在的一些问题，因此现在可以使用：

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
    NSCharacterSet *disabledLetters = [[NSCharacterSet characterSetWithCharactersInString:@" "] invertedSet];        
    NSRange location = [string rangeOfCharacterFromSet:disabledLetters];
    return (location.location == NSNotFound);
}

此代码现已更新为仅允许使用空格，输入和删除。