正则表达式-只能输入数字

1、只能输入数字

NSString *regex = @"\\d+";
NSPredicate *Pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", regex];
BOOL isMatch = [Pred evaluateWithObject:numberTF.text];
if (!isMatch){
     UIAlertController *reminderCtrl = [UIAlertController alertControllerWithTitle:@"提示" message:@"只能输入数字" preferredStyle:UIAlertControllerStyleAlert];
     [reminderCtrl addAction:[UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:nil]];
     [self presentViewController:reminderCtrl animated:YES completion:nil];
}else{
     NSLog(@"成功...");
}