Drawing 2 UIImage merged with different UILabel - ios

Question

I've been trying to create a for loop which take UILabel.text and merge it into an UIImage then save it into an instance and then when getting into the for loop second time it would save the result in different instance.
The problem that I'm facing is that it is saving the first UIImage but with low quality and skipping the second one. I've even tried to do the UIImage saving code in a button action but still didn't work.
-(void)CreateTheImage{
UIImage * img = [UIImage imageNamed:#"SquareBackground.jpg"];
UIGraphicsBeginImageContext(_imgView.bounds.size);
int Counter = 0;
for (UIView * view in [_imgView subviews]){
[view removeFromSuperview];
}
NSString *txt1 = #"Test";
NSString *txt2 = #"Worked Well";
[array addObject:txt1];
[array addObject:txt2];
UILabel *lbl = [[UILabel alloc]init];
NSLog(#"%i",[array count]);
NSLog(#"Before the loop");
for (int x = 0; x < [array count]; x++) {
NSLog(#"Entered the loop");
NSLog(#"x = %i",x);
lbl.text = [array objectAtIndex:x];
NSLog(#"lbl.text = %#",[array objectAtIndex:x]);
lbl.textAlignment = NSTextAlignmentCenter;
[lbl setBackgroundColor:[UIColor clearColor]];
lbl.font = [UIFont boldSystemFontOfSize:16];
[lbl setFrame:CGRectMake(20,112.5, 260, 75)];
[_imgView addSubview:lbl];
[_imgView bringSubviewToFront:lbl];
[_imgView setImage:img];
[_imgView.layer renderInContext:UIGraphicsGetCurrentContext()];
Counter = x+1;
NSLog(#"counter = %i",Counter);
switch (Counter) {
case 1:
NSLog(#"swintch case 1");
newImage1 = UIGraphicsGetImageFromCurrentImageContext();
break;
case 2:
NSLog(#"swintch case 2");
newImage2 = UIGraphicsGetImageFromCurrentImageContext();
break;
default:
break;
}
NSLog(#"after switch");
UIGraphicsEndImageContext();
}
//To save the picture in the album
UIImageWriteToSavedPhotosAlbum(newImage1, nil, nil, nil);
UIImageWriteToSavedPhotosAlbum(newImage2, nil, nil, nil);
NSLog(#"After the loop");
}
Also when I run this method on my iPhone it gives me a warning which is
CreatingVideo[334] : CGContextSaveGState: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid context and is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.

Answer 1

Your code doesn't make sense. You have a for loop that runs through an array, adds images to an image view, captures 1 of 2 images from the current off-screnen context, and then ends the image context after the first pass through the array. On the second pass, the context doesn't exist any more, so the second end context call will fail.
Move the end context outside of your for loop. That should fix your warning.
Even then, I'm not sure if it will work to remove subviews from an image view, add new views, an render the content to a graphics context, all without returning. UIKit view drawing usually queues changes to the UI until your code returns, then renders it on the next pass through the event loop.

Answer 2

Thanks to Duncan C for helping me find the answer and correct the code to work perfectly now
-(void)CreateTheImage{
UIImage * img = [UIImage imageNamed:#"SquareBackground.jpg"];
UIGraphicsBeginImageContextWithOptions(CGSizeMake(320, 320), NO, 0.0f);
int Counter = 0;
NSString *txt1 = #"Test";
NSString *txt2 = #"Worked Well";
[array addObject:txt1];
[array addObject:txt2];
UILabel *lbl = [[UILabel alloc]init];
NSLog(#"%i",[array count]);
NSLog(#"Before the loop");
for (int x = 0; x < [array count]; x++) {
for (UIView * view in [_imgView subviews]){
[view removeFromSuperview];
}
NSLog(#"Entered the loop");
NSLog(#"x = %i",x);
lbl.text = [array objectAtIndex:x];
NSLog(#"lbl.text = %#",[array objectAtIndex:x]);
lbl.textAlignment = NSTextAlignmentCenter;
[lbl setBackgroundColor:[UIColor clearColor]];
lbl.font = [UIFont boldSystemFontOfSize:25];
[lbl setFrame:CGRectMake(20,122.5, 280, 75)];
[_imgView addSubview:lbl];
[_imgView bringSubviewToFront:lbl];
[_imgView setImage:img];
[_imgView.layer renderInContext:UIGraphicsGetCurrentContext()];
Counter = x+1;
NSLog(#"counter = %i",Counter);
switch (Counter) {
case 1:
newImage1 = UIGraphicsGetImageFromCurrentImageContext();
NSLog(#"swintch case 1");
break;
case 2:
NSLog(#"swintch case 2");
newImage2 = UIGraphicsGetImageFromCurrentImageContext();
break;
default:
break;
}
NSLog(#"after switch");
}
UIGraphicsEndImageContext();
//To save the picture in the album
UIImageWriteToSavedPhotosAlbum(newImage1, nil, nil, nil);
UIImageWriteToSavedPhotosAlbum(newImage2, nil, nil, nil);
NSLog(#"After the loop");
}