- (void)viewDidLoad {

    [super viewDidLoad];

    // Do any additional setup after loading the view, typically from a nib.

    

    field = [[UITextField alloc]initWithFrame:CGRectMake(100, 100, 200, 50)];

    field.placeholder = @"please input some word...";

    field.font = [UIFont systemFontOfSize:18];

    field.textColor = [UIColor blackColor];

    field.borderStyle = UITextBorderStyleRoundedRect;

    field.textAlignment = NSTextAlignmentCenter;

    field.backgroundColor = [UIColor grayColor];

    

//    field.secureTextEntry = YES;

    

    field.keyboardType = UIKeyboardTypeNumberPad;

    

    field.delegate = self;

    

    [self.view addSubview:field];

    

    // 弹出键盘

    [field becomeFirstResponder];

}

 

- (BOOL)textFieldShouldReturn:(UITextField *)textField

{

    // 关闭键盘

    [field resignFirstResponder];

    

    return YES;

}