ios在Masonry中设置了uiscrollview的内容

Question

I use pure code (not storyboard or xib) to set size of all views, and I don't want to use hard code to set frame , so I use Masonry.

Now I have a scrollView and a set of views as subviews of the scrollview, the code is like this:

[self.scrollview addSubview:[self.imageviews objectAtIndex:0]];
[[self.imageviews objectAtIndex:0] mas_makeConstraints:^(MASConstraintMaker *make) {
    make.size.equalTo(self.scrollview);
    make.top.equalTo(@0);
    make.left.equalTo(@0);
}];
for (NSInteger i = 1; i < maxcnt ; i++) {
    [self.scrollview addSubview:[self.imageviews objectAtIndex:i]];
    UIImageView *previous = [self.imageviews objectAtIndex:i-1];
    [[self.imageviews objectAtIndex:i] mas_makeConstraints:^(MASConstraintMaker *make) {
        make.size.equalTo(self.scrollview);
        make.top.equalTo(@0);
        make.left.equalTo(previous.mas_right);
    }];
}

But here comes the problem:

1) How I can use Masonry to set the contentsize of the scrollview? The following code not works well because in rotate event, self.view.frame.size.width change.

self.scrollview.contentSize = CGSizeMake(self.imageviews.count * self.view.frame.size.width, self.view.frame.size.height);

2) If I have to use the upper code to set, how to deal with rotate event so the contentsize is update well.

Answer 1

You are almost there. All you have to do is set a right constraint on the last image view. By doing so you create a "connection" between the left side of the contentView and the right side. That way the UIScrollView "knows" how much space the subviews need and adjusts the contentSize accordingly.

There is no need to set the contentSize at all. Auto Layout handles this for you and it also works when rotating the device.

I wrote a blog post about this a little while ago. It uses SnapKit but that is basically just another name for "Masonry with Swift". The syntax is pretty much the same. It describes a vertical scroll view but the idea is the same on a horizontal one.

One more small thing:

Instead of doing this:

make.top.equalTo(self.scrollview.mas_top);

You can do this:

make.top.equalTo(self.scrollview);