Remove all the subviews from a UIScrollView?

问题:

How do I remove all of the subviews from a UIScrollview?

回答1:

Let scrollView be an instance of UIScrollView.

In Objective-C, it's pretty easy. Just call makeObjectsPerformSelector:, like so:

Objective-C:

[scrollView.subviews makeObjectsPerformSelector:@selector(removeFromSuperview)];

In Swift, you don't get that runtime access, so you have to actually handle the iteration yourself.

Swift:

A concise version, from here:

scrollview.subviews.map { $0.removeFromSuperview() }

A more descriptive way to do this (from here) assumes scrollview.subviews:

let subviews = self.scrollView.subviews
for subview in subviews{
    subview.removeFromSuperview()
}

回答2:

I think you just have to be careful and not to delete the scroll indicator bars.

The code given by Adam Ko is short and elegant but it may delete the horizontal and vertical scroll indicators.

I usually do

for (UIView *v in scrollView.subviews) {
  if (![v isKindOfClass:[UIImageView class]]) {
    [v removeFromSuperview];
  }
}

Suposing you don't have UIImageView's added to the scroll manually.

回答3:

In addition to Ricardo de Cillo's, in my case I had a table view that had imageviews in the subviews that I wanted to remove.

for (UIView *v in self.tableview.subviews) {
  if ([v isKindOfClass:[UIImageView class]]) {
    [v removeFromSuperview];
  }
}

The removal of the ! in the if command, and change scrollview to self.tableview removed all images, but left the table view untouched.

回答4:

If you want to remove uiimageviews in scrollview.subviews, and you also want to keep the vertical and horizontal indicators. You can set a special "tag" to identify views and exclude vertical and horizontal indicators whose tags are 0 by default.

回答5:

Complementing the Swift concise version from a previous answer (Swift 3.0 ready):

_ = scrollView.subviews.filter { $0 is UIImageView }.map { $0.removeFromSuperview() }