remove button form scrolview

Question

hi friends...

i added one UIScrollView in my project... and i added 10 more button "fieldButton" once, then the same UIScrollView i want add ather 5 button. it i try to do this first added 10 button also coming in the scrollview .. how to remove first added 10 button befor adding other item. in the same scrollview...

if(a == 1){
    for(int i = 0; i< 10; i++){
        UIButton *fieldButton_area = [[Mos_component alloc]getComboButton:title       andFrame:CGRectMake(0, y, 180, 40)];

        [fieldButton_area addSubview:cid];
        [fieldButton_area addTarget:self action:@selector(get_Area:)  forControlEvents:UIControlEventTouchUpInside];
        [state_scroll addSubview:fieldButton_area];
   }
}
else{
    UIButton *fieldButton_state = [[Mos_component alloc]getComboButton:title andFrame:CGRectMake(0, y, 180, 40)];
    [fieldButton_state addSubview:cid];
    [fieldButton_state addTarget:self action:@selector(get_Area:)  forControlEvents:UIControlEventTouchUpInside];
    [state_scroll addSubview:fieldButton_state];
}

pls help me

Answer 1

If you want just to clear your scrollview (i.e. remove all its subviews) then you can do that following way:

for (UIView* subView in [state_scroll subviews])
    [subView removeFromSuperView];

If you want to remove some specific views you can check its types:

for (UIView* subView in [state_scroll subviews])
    if ([subView isKindOfClass:[Mos_component class]]) // remove Mos_components only
        [subView removeFromSuperView];

You can also assign tag property to you views and remove them following way:

 [[fieldButton_area viewWithTag:yourTag] removeFromSuperView];

Also note that you must release your buttons somewhere or you will get memory leak.

Answer 2

You could also try animating the button(s) off of the screen or set the alpha's to 0 then add the new UIButton's to the view. This may use more memory, but in some cases look better.

[UIView BeginAnimation];
// set time and speed here

// Perform animation here

[UIView setAnimationDidStopSelector /* here call the method for the new button's animation into the view*/];

[UIView CommitAnimations];
// Then set the button's enabled property to NO
button.enabled = NO;

I hope this is of some assistance