popViewController不适用于UIAlertView

Question

I am having problem with AlertView. I am trying to use the UIAlertView and after click ok it will return back to the previous screen but it do not seems to work any advice ?

if (xGPSCoordinate==0 && yGPSCoordinate == 0) {

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Title" 
                                                    message:@"Failed to load the to get your current location"
                                                   delegate:self 
                                          cancelButtonTitle:@"Ok" 
                                          otherButtonTitles:nil, nil];
    [alert show];
    [alert release];

    return;
    [self.navigationController popViewControllerAnimated:YES];
} 

or

if (xGPSCoordinate==0 && yGPSCoordinate == 0) {

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"iPoly" 
                                                    message:@"Failed to load the to get your current location"
                                                   delegate:self 
                                          cancelButtonTitle:@"Ok" 
                                          otherButtonTitles:nil, nil];
    [alert show];
    [alert release];
    [self.navigationController popViewControllerAnimated:YES];
    return;

}   

both doesn't work

Answer 1

For this purpose you've to use UIAlertView 's delegate method.

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex;

First use this in your @interface <UIAlertViewDelegate>

Then set the delegate, self.yourAlertView.delegate=self ;

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{

       if(buttonIndex==0)//first button which should be the OK button
       {

              [self.navigationController popViewControllerAnimated:YES];

       }

 }

Answer 2

use the delegate method of UIAlertView, see the answer given by iNoob. It does not make a sense if you write anything after the "return;" statement as the code below "return;" statement will never get executed.

refer apple developer link for more details on UIAlertView delegate http://developer.apple.com/library/ios/#DOCUMENTATION/UIKit/Reference/UIAlertViewDelegate_Protocol/UIAlertViewDelegate/UIAlertViewDelegate.html

or a simple tutorial on alert view http://mobile.tutsplus.com/tutorials/iphone/uialertview/

Answer 3

You just need to implement UIAlerView Delegate Methods.

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{}

write your code for Pop to previous Controller here.You can the clicked button index and on the basis of that you can use.Don't for Conform UIAlertViewDelegate to Interface.