我有一个带有导航栏的 UIViewController。我的 UIScrollView 包含 UIButtons 列表以编程方式添加。我使用 AutoLayout 来添加滚动视图及其按钮列表,如下所示。
在显示和关闭模式视图之前,它可以完美运行。模式视图关闭后,滚动视图中的按钮列表向下移动 44px(等于导航栏高度)。 当我尝试删除导航栏时,一切正常。
我搜索了以下问题,但不是我的情况:
关闭 ModalViewController 后 UIScrollView 的内容发生了变化
我使用 AutoLayout 添加 uiscrollview 的代码:
UIScrollView* scrollView = [UIScrollView new];
[scrollView setTranslatesAutoresizingMaskIntoConstraints:NO];
//calculate contentSize based on the button count
int buttonCount = 10;
CGSize contentSize = CGSizeMake(ICON_X*2 + (ICON_WIDTH + ICON_SPACE) * buttonCount - ICON_SPACE, ICON_HEIGHT);
//calculate trailing offset for the first button
CGFloat trailingOffset = contentSize.width - (ICON_X + ICON_WIDTH);
//add list of button to the scrollview
for (int i = 0; i < buttonCount; i++) {
UIButton * button = [UIButton buttonWithType:UIButtonTypeCustom];
[button setTranslatesAutoresizingMaskIntoConstraints:NO];
//set button image
//set button target
//set tag
button.tag = i;
//add to the scroll view
[scrollView addSubview:button];
//calculate the button's frame using AutoLayout
NSDictionary *dict = NSDictionaryOfVariableBindings(button);
[scrollView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:[NSString stringWithFormat:@"H:|-%g-[button(%d)]-%g-|", ICON_X + (ICON_WIDTH + ICON_SPACE)*i, ICON_WIDTH, trailingOffset] options:NSLayoutFormatAlignAllCenterY metrics:nil views:dict]];
[scrollView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:[NSString stringWithFormat: @"V:|-%g-[button(%d)]-%g-|", ICON_Y, ICON_HEIGHT, ICON_Y] options:NSLayoutFormatAlignAllCenterY metrics:nil views:dict]];
//update the trailing offset for the next button
if (i == buttonCount - 2) //the next one is the last button
trailingOffset = ICON_X;
else
trailingOffset -= (ICON_SPACE + ICON_WIDTH);
}
//add the scrollView to self.viewIcon
//self.viewIcon is a UIView which was added as a subview of self.view in the storyboard using AutoLayout
[self.viewIcon addSubview:scrollView];
//calculate the scrollview's frame using AutoLayout
//contraint autolayout
NSArray *verticalConstraints = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-(1)-[scrollView(58)]" options:0 metrics:nil views:NSDictionaryOfVariableBindings(scrollView)];
NSArray *horizontalContraints = [NSLayoutConstraint constraintsWithVisualFormat:@"|[scrollView]|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(scrollView)];
[self.viewIcon addConstraints:verticalConstraints];
[self.viewIcon addConstraints:horizontalContraints];
请注意,滚动视图被添加到 self.viewIcon,它是使用 AutoLayout 在情节提要中作为 self.view 的子视图添加的
谢谢