限制UITextField的输入只为数字的方法

实现下面的委托

#define NUMBERS @"0123456789\n"

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string

{

NSCharacterSet *cs;

if(textField == phoneNumberField)

{

cs = [[NSCharacterSet characterSetWithCharactersInString:NUMBERS] invertedSet];

NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];

BOOL basicTest = [string isEqualToString:filtered];

if(!basicTest)

{

UIAlertView* alert = [[UIAlertView alloc] initWithTitle:@"提示"

message:@"请输入数字"

delegate:nil

cancelButtonTitle:@"确定"

otherButtonTitles:nil];

[alert show];

[alert release];

return NO;

}

}

//其他的类型不需要检测，直接写入

return YES;

}

如果输入的不是数字，进行提示。