How to remove duplicate buttons - ios

Question

I created five buttons using for loop, it works well. Whenever i click restart button duplicate buttons created
-(void)buttonCreate {
for( int i = 0; i < 5; i++ )
{
oneBtn1 = [UIButton buttonWithType:UIButtonTypeCustom];
oneBtn1.frame = CGRectMake(316,i*-5+474,51,50);
[oneBtn1 setTag:i];
[oneBtn1 addTarget:self action:#selector(oneButton:) forControlEvents:UIControlEventTouchUpInside];
[oneBtn1 setImage:[UIImage imageNamed:#"1c.png"] forState:UIControlStateNormal];
[self.view addSubview:oneBtn1];
}
}
Restart button function:
-(void)restart {
[self buttonCreate];
}
I tried this one but it will remove only one button out of 5.
if(oneBtn1 != NULL) {
[oneBtn1 removeFromSuperview];
oneBtn1 = nil;
}
Problem is: How to remove duplicate buttons?

Answer 1

Create an array(NSMutableArray *buttonHolderArray) to hold outlets for all five buttons.
[buttonHolderArray addObject:oneBtn1];
Then you can remove/update the buttons as and when you need.
And once you dont want any button, empty the array itself. On top of this, if you wish to clear the view then simply call removeFromSuperView for all the buttons
I tried this one but it will remove only one button out of 5.
if(oneBtn1 != NULL) {
[oneBtn1 removeFromSuperview];
oneBtn1 = nil;
}
You are removing only one button, if you want to remove all then use
for ( UIButton *button in buttonHolderArray){
button removeFromSuperView];
}

Answer 2

You can remove by checking if the button is already created.
-(void)buttonCreate {
int tag_start = 500;
for( int i = 0; i < 5; i++ )
{
UIView * prevbtn = [self.view viewWithTag:tag_start + i];
if(prevbtn) {
[prevbtn removeFromSuperview];
}
oneBtn1 = [UIButton buttonWithType:UIButtonTypeCustom];
oneBtn1.frame = CGRectMake(316,i*-5+474,51,50);
[oneBtn1 setTag:tag_start + i];
[oneBtn1 addTarget:self action:#selector(oneButton:) forControlEvents:UIControlEventTouchUpInside];
[oneBtn1 setImage:[UIImage imageNamed:#"1c.png"] forState:UIControlStateNormal];
[self.view addSubview:oneBtn1];
}
}

Answer 3

use this before calling again restart method
for (UIButton *btn in self.view.subviews ) {
[btn removeFromSuperview];
}

Answer 4

Before the restart button clicked you can remove all the buttons from you view calling the method removeChildViewsWithKindOfClass
-(void)restart {
[self.view removeChildViewsWithKindOfClass:[UIButton class]];
[self buttonCreate];
}
-(void)removeChildViewsWithKindOfClass:(Class)classToRemove{
if (classToRemove==nil) return;
for (UIView *v in [self subviews]) {
if ([v isKindOfClass:classToRemove]) {
[v removeFromSuperview];
}
}
}
If you want to remove a specific button you can use the property tag that you have to set beforehand when you create your button and it allows you removing the button with a specific tag.