iOS UIAlertView没有显示

Question

I want to pop up a simple message window when a user touches the button, in an IPhone app. I used UIAlertView class, in the implementation code like this:

-(IBAction)sendMessage:(UIButton *)sender

{
    UIAlertView *alert=[[UIAlertView alloc] initWithTitle:@"test message"
                                                         message:@"test"
                                                        delegate:nil
                                               cancelButtonTitle:@"OK"
                                        otherButtonTitles:nil];


    [alert show];
}

I also linked sendMessage method action to touch up inside.

Shows nothing.

Have any ideas? I'm new to iOS programming. Thanks for helping.

Answer 1

您需要将情节提要/ xib文件中的按钮链接到函数或调用或通过代码进行设置

[button addTarget:self action:@selector(sendMessage:) forControlEvents:UIControlEventTouchUpInside];

Answer 2

I would suggest two things, give it a try:

1) Set delegate to self .

2) Try making the IBAction argument type to id . Then remove and reconnect from Interface builder.

Something like this:

-(IBAction)sendMessage:(id)sender

{
    UIAlertView *alert=[[UIAlertView alloc] initWithTitle:@"test message"
                                                         message:@"test"
                                                        delegate:self
                                               cancelButtonTitle:@"OK"
                                        otherButtonTitles:nil];


    [alert show];
}

Answer 3

  NSString* messageString = [NSString stringWithFormat: @"\"%@ \"does not apppear to be valid email address.Do You Want sent Anyway?", email];

            UIAlertView *alertView =[[UIAlertView alloc]initWithTitle:@"Invalid adress" message:messageString delegate:self cancelButtonTitle:@"Cancel" otherButtonTitles:@"OK", nil];
            [alertView show];