默认在 UISplitViewController 上显示 Master

Question

当我为 Mac (v8.4.5) 创建一个带有 Visual Studio 的新 "Master Detail App" 时，UISplitViewController 的默认行为是显示 详细信息页面出现在纵向模式下的iPhone上时第一页。

我宁愿（我认为大多数人都愿意）默认显示 Master 页面。在我的例子中，母版页是一个 table 包含联系人列表的视图。

这个问题类似于：UISplitViewController in portrait on iPhone shows detail VC instead of master 但是 Xamarin.iOS

与那里建议的解决方案类似，我尝试分配委托但没有成功：

    public class ContactsSplitViewControllerDelegate : UISplitViewControllerDelegate
    {
        public override bool EventShowViewController(UISplitViewController splitViewController, UIViewController vc, NSObject sender)
        {
            return true;
        }

        public override bool EventShowDetailViewController(UISplitViewController splitViewController, UIViewController vc, NSObject sender)
        {
            return true;
        }
    }

    public partial class ContactsSplitViewController : UISplitViewController
    {
        public ContactsSplitViewController (IntPtr handle) : base (handle)
        {
            this.Delegate = new ContactsSplitViewControllerDelegate();
        }

    }

Answer 1

设置PreferredDisplayMode

public override void ViewDidLoad()
{
    base.ViewDidLoad();

    this.PreferredDisplayMode = UISplitViewControllerDisplayMode.AllVisible;
}

Answer 2

经过一些试验，覆盖委托的 CollapseSecondViewController 似乎会起作用，但我还不确定这是正确的解决方案。

using Foundation;
using System;
using UIKit;

namespace MasterDetailTest
{
    public class SplitViewControllerDelegate : UISplitViewControllerDelegate
    {
        public override bool CollapseSecondViewController(UISplitViewController splitViewController, UIViewController secondaryViewController, UIViewController primaryViewController)
        {
            return true;
        }
    }

    public partial class MainPageSplitViewController : UISplitViewController
    {
        public MainPageSplitViewController (IntPtr handle) : base (handle)
        {
            this.Delegate = new SplitViewControllerDelegate();
        }

        public override void ViewDidLoad()
        {
            base.ViewDidLoad();

            // When implemented in my project, I found I needed to set this
            // or the delegate would not be called.
            this.SetNeedsFocusUpdate();
        }

    }
}

默认在 UISplitViewController 上显示 Master

Show Master on UISplitViewController by Default

xamarin.ios

uisplitviewcontroller