iOS 限制只能输入数字（字母）

#define NUMBERS @"0123456789"

#define ENGLISH @"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefjhigklmnopqrstuvwxyz"

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

{

NSCharacterSet*cs;

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];

return NO;

}

return YES;

}