一旦敲击，UISearchBar跳出位置

Question

我试图显示一个MySearchBar（加上UISearchBar来显示标题的UILabel）作为navigationItem的观点：

// Make search bar autoresize and occupy maximum width
self.navigationItem.titleView = [[UIView alloc] initWithFrame:self.navigationController.navigationBar.bounds];
self.navigationItem.titleView.autoresizingMask = UIViewAutoresizingFlexibleWidth;
[self.navigationItem.titleView addSubview:self.mySearchBar.view];
self.mySearchBar.view.frame = self.navigationItem.titleView.frame;

搜索栏就位，直到它被点击。点击后，它向下移动，不再占据全宽（大约16px缺失）。

在编辑之前（它应该如何看）：

编辑开始（BUG - 点击搜索栏后，高度增加到默认的56px并丢失宽度）：

编辑结束（仍然放错地方）

这是MySearchBar的初始化代码。它包括两个主要视图，titleView用标题包装UILabel和searchBarWrapperView包裹UISearchBar：

-(id) init {
    // Initialize the two wrapping views
    UIView *titleView = [UIView new];
    self.searchBarWrapperView = [UIView new];

    // Resize UILabel to fit its content
    self.titleLabel = [UILabel new];
    self.titleLabel.numberOfLines = 0;
    [self.titleLabel sizeToFit];

    self.searchBar = self.searchController.searchBar;
    self.searchBarTextField = [self.searchBar valueForKey:@"searchField"];// This could be the text field that gets displaced???

    // Add two main subviews (wrappers)
    [self.view addSubview:titleView];
    [self.view addSubview:self.searchBarWrapperView];

    // Add title label and search bar to the subviews
    [titleView addSubview:self.titleLabel];
    [self.searchBarWrapperView addSubview:self.searchBar];

    // Disable auto constraints
    [titleView setTranslatesAutoresizingMaskIntoConstraints:NO];
    [self.searchBarWrapperView setTranslatesAutoresizingMaskIntoConstraints:NO];
    [self.titleLabel setTranslatesAutoresizingMaskIntoConstraints:NO];

    // Set constraints for title view
    [titleView.topAnchor constraintEqualToAnchor:self.view.topAnchor].active = YES;
    [titleView.leftAnchor constraintEqualToAnchor:self.view.leftAnchor].active = YES;
    [titleView.rightAnchor constraintEqualToAnchor:self.view.rightAnchor].active = YES;
    [titleView.bottomAnchor constraintEqualToAnchor:self.titleLabel.bottomAnchor].active = YES;

    // Set constraints for title label
    [self.titleLabel.topAnchor constraintEqualToAnchor:titleView.topAnchor].active = YES;
    [self.titleLabel.leftAnchor constraintEqualToAnchor:titleView.leftAnchor].active = YES;
    [self.titleLabel.rightAnchor constraintEqualToAnchor:titleView.rightAnchor].active = YES;

    // Set constraints for search bar wrapper
    [self.searchBarWrapperView.heightAnchor constraintGreaterThanOrEqualToConstant:30].active = YES;// The search bar together with the title label should occupy the whole 44px height of the navigation bar
    [self.searchBarWrapperView.topAnchor constraintEqualToAnchor:titleView.bottomAnchor].active = YES;
    [self.searchBarWrapperView.bottomAnchor constraintEqualToAnchor:self.view.bottomAnchor].active = YES;
    [self.searchBarWrapperView.leftAnchor constraintEqualToAnchor:self.view.leftAnchor].active = YES;
    [self.searchBarWrapperView.rightAnchor constraintEqualToAnchor:self.view.rightAnchor constant:16].active = YES;// Add space that is lost by setSearchFieldBackgroundPositionAdjustment

    // Configure autoresizing mask for UISearchBar
    [self.searchBar setAutoresizingMask:UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight];
    [self.searchBar setFrame:self.searchBarWrapperView.frame];

    //Remove left and right blank spaces around UISearchBar
    [self.searchBar setSearchFieldBackgroundPositionAdjustment:UIOffsetMake(-8,0)];

    // Colors for debugging        
    self.view.backgroundColor = [UIColor blueColor];
    titleView.backgroundColor = [UIColor redColor];
    searchBarWrapperView.backgroundColor = [UIColor greenColor];
    self.searchBar.backgroundColor = [UIColor yellowColor];
    self.searchBarTextField.backgroundColor = [UIColor brownColor];

    return self;
}