如何将 NSStackView 注入视图层次结构？

Question

我有一个用 Objective-C 编写的 OSX 应用程序。它在 NSWindow 中显示一些 NSView，问题是我无法修改它的代码。原始模型层次结构如下所示：

NSWindow
|---> original NSView
      |---> (...)

我想按如下方式更改层次结构：

NSWindow
|---> NSStackView
      |---> original NSView
      |     |---> (...)
      |---> some additional NSView (say NSTextField)

如何使用 NSStackView 将原始 NSView 和附加的 NSView 并排显示？

我目前的做法或多或少是这样的（示例已简化）：

- (void)createFirstView {
    NSTextField *label1 = [NSTextField labelWithString:@"First view."];
    [_window setContentView: label1];
}

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
    // I cannot modify this procedure:
    [self createFirstView];

    // I can modify that:
    NSTextField *label2 = [NSTextField labelWithString:@"Second view."];

    NSView *firstView = [_window contentView];
    [firstView removeFromSuperview];
    NSStackView *st = [NSStackView stackViewWithViews:@[firstView, label2]];
    [_window setContentView:st];
}

不幸的是运行之后的 NSWindow 此代码仅显示 "Second view" 标签：

Answer 1

[_window setContentView:st] 在旧内容视图上调用 removeFromSuperview，然后 removeFromSuperview 释放视图。 [firstView removeFromSuperview] 和 [_window setContentView:st] 都会释放 firstView。

解决方案：将[firstView removeFromSuperview]替换为[_window setContentView:nil]。

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
    // I cannot modify this procedure:
    [self createFirstView];

    // I can modify that:
    NSTextField *label2 = [NSTextField labelWithString:@"Second view."];

    NSView *firstView = [_window contentView];
    [_window setContentView:nil];
    NSStackView *st = [NSStackView stackViewWithViews:@[firstView, label2]];
    [_window setContentView:st];
}

如何将 NSStackView 注入视图层次结构？

How to inject a NSStackView into the view hierarchy?

objective-c

nsview

appkit

retain

nsstackview