Change UIButton image within a cell - objective-c

Question

I am having difficulty in changing the image of my UIButton which is contained within a table view cell. My code as follows:
// In tableview for cell at rowIndex method
self.iconBtn = [[UIButton alloc]initWithFrame:CGRectMake(670,10,80, 80)];
self.iconBtn.tag = kIconValueTag;
[cell.contentView addSubview:self.iconBtn];
//Add icon to cell
UIImage *btnImage = [UIImage imageNamed:#"blank_star.png"];
[self.iconBtn setImage:btnImage forState:UIControlStateNormal];
// I am calling method changeIconState after user clicks on icon.
[self.iconBtn addTarget:self action:#selector(changeIconState) forControlEvents:UIControlEventTouchUpInside];
After the button is pressed, a method outside the table view method is called:
-(void)changeIconState
{
if (self.iconSelectState == kIconNotSelected)
{
self.iconSelectState = kIconSelected;
}
else
{
self.iconSelectState = kIconNotSelected;
}
[self changeIcon];
}
-(void)changeIcon
{
if (self.iconSelectState == kIconSelected)
{
UIImage *btnImageHighlighted = [UIImage imageNamed:#"star.png"];
[self.iconBtn setImage:btnImageHighlighted forState:UIControlStateNormal];
}
else
{
UIImage *btnImageNormal = [UIImage imageNamed:#"blank_star.png"];
[self.iconBtn setImage:btnImageNormal forState:UIControlStateNormal];
}
}
After I run the program, the icon did not change from blank to star as I wanted. It just remained as a blank star. Is there anything I am missing out here?

Answer 1

Why are you managing the image/button state yourself? Why not load the two images for the defined states and let the OS handle it?
//Add icon to cell
UIImage *btnImage = [UIImage imageNamed:#"blank_star.png"];
UIImage *btnImageHighlighted = [UIImage imageNamed:#"star.png"];
[self.iconBtn setImage:btnImage forState:UIControlStateNormal];
[self.iconBtn setImage:btnImageHighlighted forState:(UIControlStateHighlighted && UIControlStateSelected)];
If you need to manage your property (iconSelectedState) you can without worrying about the image. Alternatively, you can query the buttons state property to determine which state it is in.