iOS UIButton disappears after setting background image to nil

Question

I have a UIButton that has no title or initial background image. When pressed, the button background image changes and when pressed again, it is set to nil. Now with iOS 6.x, the button completely disappears. Here is my code:

- (IBAction)resetAll: (id) sender {
[self reset];

for (UIView *view in self.view.subviews) {

    if ([[[view class] description] isEqualToString:@"UIRoundedRectButton"]) {
        UIButton *theButton = (UIButton *)view;         

        int nTag = theButton.tag;

        switch (nTag) {
            case 11: {
                theButton.tag = 10;
                [theButton setBackgroundImage:nil forState:UIControlStateNormal];
                break;
            }
            case 21: {
                theButton.tag = 20;
                [theButton setBackgroundImage:nil forState:UIControlStateNormal];
                [theButton setEnabled:YES];
                break;
            }
            case 31: {
                theButton.tag = 30;
                [theButton setBackgroundImage:nil forState:UIControlStateNormal];
                [theButton setEnabled:YES];
                break;
            }
            case 41: {
                theButton.tag = 40;
                [theButton setBackgroundImage:nil forState:UIControlStateNormal];
                [theButton setEnabled:YES];
                break;
            }
            case 51: {
                theButton.tag = 50;
                [theButton setBackgroundImage:nil forState:UIControlStateNormal];
                [theButton setEnabled:YES];
                break;
            }
        }
    }
}
return;

This code works fine:

- (IBAction)ButtonClicked: (id) sender {
UIButton *btn = (UIButton *)sender;

// Get the current tag value
int currentTag = [sender tag];

// Toggle the check buttons
if (currentTag == 10 || currentTag == 20 || currentTag == 30 || currentTag == 40 || currentTag == 50) {
        [btn setBackgroundImage:[UIImage imageNamed:@"check.png"] forState:UIControlStateNormal];
        btn.tag = ++currentTag;
}

else
    if (currentTag == 11 || currentTag == 21 || currentTag == 31 || currentTag == 41 || currentTag == 51) {
        [btn setBackgroundImage:nil forState:UIControlStateNormal];
        btn.tag = --currentTag;
}

[self calculate];

Any suggestions or help would be appreciated!

Answer 1

Instead of changing the background image of the button in the UIControlStateNormal, why not instead just change states of the button? If you created the button programmatically, you just need to add the line

[btn setBackgroundImage:[UIImage imageNamed:@"check.png"] forState:UIControlStateSelected];

Then, when pressed and you want it to be the arrow image:

[btn setSelected:YES];

and to set it back to the default appearance:

[btn setSelected:NO];

If you made the button in a XIB, you can set the state images by changing the state config to Selected and set the image there.