Crash in background thread

[mbcoder17]

I am trying to display an SCLAlertView in my app, but I am getting this error:

Thread 1: EXC_BAD_ACCESS (code=EXC_1386_GPFLT)

on this line [keyWindow.layer renderInContext:context];

I am creating the alert after I call one of my parse cloud code functions. I have read that renderInContext should not be called in a background thread, but I have this exact same code in a different view controller (also after I call a cloud code function), and the alert displays perfectly.

Also, if I display and hide a regular UIAlertView immediately before I show this one, the SCLAlertView shows without a problem, but the view behind it is a solid white. Why is this happening? Is UIAlertView somehow breaking out of the background thread?

I have tried displaying the SCLAlertView in a background thread as suggested here: http://stackoverflow.com/questions/15135208/objective-c-renderincontext-crash-on-background-thread but the app still crashed.

Here is my code to display the alert:

[PFCloud callFunctionInBackground:@"canWeStart"
                           withParameters:@{@"inviteId": self.selectedObject.objectId,
                                            @"gameType": [[self.selectedObject objectForKey:@"GameType"] objectForKey:@"type"]}
                                    block:^(NSArray *startStuff, NSError *error) {
                                        if (!error) {

                                            NSNumber *canStart = startStuff[0];

                                            BOOL startBool = [canStart boolValue];

                                            if(startBool)
                                            {
                                               //Stuff

                                            }
                                            else
                                            {

                                                //If I show this first, my alert shows perfectly.
                                                UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Others" message:@"Need to accept" delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil];
                                                [alert show];

                                                [alert dismissWithClickedButtonIndex:0 animated:NO];

                                                SCLAlertView *alert = 

[[SCLAlertView alloc] init];

        alert.backgroundType = Blur;

        //button.layer.borderWidth = 2.0f;

        [alert setTitleFontFamily:@"Alba" withSize:18.0f];

        [alert setBodyTextFontFamily:@"Arista 2.0" withSize:14.0f];

        [alert setButtonsTextFontFamily:@"Arista 2.0 Light" withSize:14.0f];

        alert.customViewColor = [UIColor pxColorWithHexValue:@"2b3355"];

        alert.backgroundViewColor = [UIColor whiteColor];

        [alert showNotice:self.navigationController title:@"Invite Accepted" subTitle:@"Others still need to accept the invite, then the game will begin!" closeButtonTitle:@"Ok" duration:0.0f];

                                                }

                                            }

                                        }];

[dogo]

Please test the following code:

Replace makeBlurBackground by :

- (void)makeBlurBackground
{
    UIImage *image = [UIImage convertViewToImage:_rootViewController.view];
    UIImage *blurSnapshotImage = [image applyBlurWithRadius:5.0f
                                         tintColor:[UIColor colorWithWhite:0.2f
                                                                     alpha:0.7f]
                             saturationDeltaFactor:1.8f
                                         maskImage:nil];

    _backgroundView.image = blurSnapshotImage;
    _backgroundView.alpha = 0.0f;
    _backgroundOpacity = 1.0f;
}

Replace convertViewToImage by :

#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v)  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)
+ (UIImage*)convertViewToImage:(UIView *)view
{
    CGFloat scale = [UIScreen mainScreen].scale;
    UIImage *capturedScreen;

    if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0"))
    {
        //Optimized/fast method for rendering a UIView as image on iOS 7 and later versions.
        UIGraphicsBeginImageContextWithOptions(view.bounds.size, YES, scale);
        [view drawViewHierarchyInRect:view.bounds afterScreenUpdates:YES];
        capturedScreen = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
    }
    else
    {
        //For devices running on earlier iOS versions.
        UIGraphicsBeginImageContextWithOptions(view.bounds.size,YES, scale);
        [view.layer renderInContext:UIGraphicsGetCurrentContext()];
        capturedScreen = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
    }

    return capturedScreen;
}

[mbcoder17]

Hi, thank you for the very quick response! I replaced both of those methods and the alert now displays. Thank you very much! :)