iPhone限制用户在文本字段中输入空间
问题描述：
我想限制用户在UITextField中输入空格。为此我使用此代码
i want to restrict user from entering space in a UITextField. for this i m using this code
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
if ( string == @" " ){
UIAlertView *error = [[UIAlertView alloc] initWithTitle:@"Error" message:@"You have entered wrong input" delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
[error show];
return NO;
}
else {
return YES;
}
}
但它不起作用....什么是错了吗？
but it is not working .... what is wrong in it ?
答
问题是
string == @" "
错误。字符串的平等使用：
is wrong. Equality for strings is done using:
[string isEqualToString:@" "]
：）。