Question

got this code:

[self setQRCodeScannerMode:false];
[self.activityIndicator startAnimating];
TBXMLSuccessBlock successBlock = ^(TBXML *tbxmlDocument) {
    if ([[TBXML elementName:tbxmlDocument.rootXMLElement] isEqualToString:@"xxxxxx"]){
        [self setQRCodeScannerMode:true];
    } else {
        [self setQRCodeScannerMode:true];
    }
};

The thing is that when I set my scan mode to true inside the method [setQRCodeScannerMode] I’m stopping the activity indicator.
But surprise!!! the activity indicator is still working and messing with my view after some seconds.

What can I do?

Answer 1

You need to stop the activity indicator in your completion block:

[self setQRCodeScannerMode:false];
[self.activityIndicator startAnimating];
TBXMLSuccessBlock successBlock = ^(TBXML *tbxmlDocument) {
    if ([[TBXML elementName:tbxmlDocument.rootXMLElement] isEqualToString:@"xxxxxx"]){
        [self setQRCodeScannerMode:true];
    } else {
        [self setQRCodeScannerMode:true];
    }

    [self.activityIndicator stopAnimating];
};

This assumes the completion block is called on the main thread. If there is no guarantee that the completion block is called on the main thread you can do this:

[self setQRCodeScannerMode:false];
[self.activityIndicator startAnimating];
TBXMLSuccessBlock successBlock = ^(TBXML *tbxmlDocument) {
    if ([[TBXML elementName:tbxmlDocument.rootXMLElement] isEqualToString:@"xxxxxx"]){
        [self setQRCodeScannerMode:true];
    } else {
        [self setQRCodeScannerMode:true];
    }

    if ([NSThread isMainThread]) {
        [self.activityIndicator stopAnimating];
    } else {
        dispatch_async(dispatch_get_main_queue(), ^{
            [self.activityIndicator stopAnimating];
        });
    }
};