c# - 监听以编程方式创建的 NSView 的事件

Question

我使用 NSOutlineView 在我的 C#/MonoMac 应用程序中创建了一个侧边栏，并获得了创建问题 Create NSView programmatically in Xamarin Studio 中的项目的帮助。 。但现在我已经使大纲 View 中的一些项目可编辑，当然我想检测这些项目何时被编辑并采取行动(编辑底层模型，或者如果编辑了特殊的“创建新”项目，则创建一个新模型)。

可以通过双击或选择项目后按 Return 键来编辑项目。但我不知道如何检测代码中的项目何时被编辑。我尝试覆盖 NSOutlineViewDataSource 中的 CommitEditing，并覆盖 NSOutlineViewDelegate 中的 CommitEditing 和 ShouldEditTableColumn。这些似乎都没有被调用。

我还尝试将 EditingEnded 的事件处理程序连接到 NSTextField，它是我在 NSOutlineViewDelegate.GetView 方法中调用 MakeView 时获得的 View 的 subview 。但这会使应用程序崩溃。当我尝试设置 NSTextField 的委托(delegate)并在其中覆盖 EditingEnded 或 TextShouldEndEditing 时，我也会崩溃。进入编辑模式后一按下键就会崩溃。

现在我迷路了。感觉好像我已经尝试了一切。

如果您想查看代码，请点击此处:

型号:https://code.google.com/p/yet-another-music-application/source/browse/trunk/Player/GUIs/OSX/Models/Navigation.cs

View Controller :https://code.google.com/p/yet-another-music-application/source/browse/trunk/Player/GUIs/OSX/Views/NavigationViewController.cs

这是我使用此代码订阅 Changed 事件时发生的崩溃:

    // ...
    view = outlineView.MakeView ("DataCell", this);
    ((NSTextField)view.Subviews [1]).Changed += foo;
}

private void foo(object sender, EventArgs e) {
    Console.WriteLine("changed text field.");
};

2013-08-02 08:53:32.851 Stoffi[6582:1007] -[__NSCFType controlTextDidEndEditing:]: unrecognized selector sent to instance 0x16a6c402013-08-02 08:53:32.852 Stoffi[6582:1007] Exception detected while handling key input.2013-08-02 08:53:32.852 Stoffi[6582:1007] -[__NSCFType controlTextDidEndEditing:]: unrecognized selector sent to instance 0x16a6c402013-08-02 08:53:32.863 Stoffi[6582:1007] (    0   CoreFoundation                      0x9966be8b __raiseError + 219    1   libobjc.A.dylib                     0x98a8f52e objc_exception_throw + 230    2   CoreFoundation                      0x9966fafd -[NSObject(NSObject) doesNotRecognizeSelector:] + 253    3   CoreFoundation                      0x995b7e87 ___forwarding___ + 487    4   CoreFoundation                      0x995b7c32 _CF_forwarding_prep_0 + 50    5   Foundation                          0x93d36e52 __57-[NSNotificationCenter addObserver:selector:name:object:]_block_invoke_0 + 49    6   CoreFoundation                      0x9962d851 ___CFXNotificationPost_block_invoke_0 + 257    7   CoreFoundation                      0x99578e8a _CFXNotificationPost + 2794    8   Foundation                          0x93d1f988 -[NSNotificationCenter postNotificationName:object:userInfo:] + 92    9   AppKit                              0x972b9926 -[NSTextField textDidEndEditing:] + 405    10  Foundation                          0x93d36e52 __57-[NSNotificationCenter addObserver:selector:name:object:]_block_invoke_0 + 49    11  CoreFoundation                      0x9962d851 ___CFXNotificationPost_block_invoke_0 + 257    12  CoreFoundation                      0x99578e8a _CFXNotificationPost + 2794    13  Foundation                          0x93d1f988 -[NSNotificationCenter postNotificationName:object:userInfo:] + 92    14  AppKit                              0x96fd762b -[NSTextView(NSPrivate) _giveUpFirstResponder:] + 434    15  AppKit                              0x96fd746f -[NSTextView(NSKeyBindingCommands) insertNewline:] + 580    16  libobjc.A.dylib                     0x98a9c5d3 -[NSObject performSelector:withObject:] + 70    17  AppKit                              0x96fd714e -[NSResponder doCommandBySelector:] + 91    18  AppKit                              0x96fd6f83 -[NSTextView doCommandBySelector:] + 152    19  AppKit                              0x97067fe3 -[NSTextInputContext doCommandBySelector:] + 121    20  AppKit                              0x97067f5d -[NSTextInputContext _handleCommand:] + 84    21  AppKit                              0x97062929 -[NSKeyBindingManager(NSKeyBindingManager_MultiClients) interpretEventAsCommand:forClient:] + 2006    22  AppKit                              0x97061db5 -[NSTextInputContext handleEvent:] + 1298    23  AppKit                              0x97061825 -[NSView interpretKeyEvents:] + 205    24  AppKit                              0x96fa43b8 -[NSTextView keyDown:] + 680    25  AppKit                              0x971c8af1 -[NSWindow sendEvent:] + 7432    26  AppKit                              0x971c390f -[NSApplication sendEvent:] + 4278    27  AppKit                              0x970dd62c -[NSApplication run] + 951    28  AppKit                              0x970805f6 NSApplicationMain + 1053    29  ???                                 0x060c9e76 0x0 + 101490294    30  ???                                 0x060c9c70 0x0 + 101489776    31  ???                                 0x007beff8 0x0 + 8122360    32  ???                                 0x007bf156 0x0 + 8122710    33  libmono-2.0.dylib                   0x0100be52 mono_jit_runtime_invoke + 722    34  libmono-2.0.dylib                   0x011a767a mono_runtime_invoke + 170    35  libmono-2.0.dylib                   0x011aa1f1 mono_runtime_exec_main + 705    36  libmono-2.0.dylib                   0x011a9401 mono_runtime_run_main + 929    37  libmono-2.0.dylib                   0x010695e5 mono_jit_exec + 149    38  libmono-2.0.dylib                   0x0106bb79 mono_main + 9609    39  Stoffi                              0x0000308f main + 2047    40  Stoffi                              0x00002885 start + 53)

Answer 1

订阅 GetView 内文本字段上的事件对我来说效果很好。该问题必须存在于代码中的其他位置...

<小时/>

编辑添加:

做这样的事情要小心:

((NSTextField)view.Subviews [1]).Delegate = new PlaylistNavigationDelegate ();

并且，根据您最初的尝试将事件分配给匿名方法。

在这种情况下，一旦控制权离开 GetView 的范围，对委托(delegate)的唯一引用就位于非托管端。 Mono GC 看不到这一点，并且委托(delegate)有资格进行收集。当托管引用从 Cocoa 下被垃圾回收时，这可能会导致各种问题。

<小时/>

工作示例:

// MainWindowController...

        public override void AwakeFromNib()
        {
            rootNode = new Node(new NSString("Root Node"));

            for(int i = 1; i <=5; i++)
            {
                rootNode.Children.Add(new Node(new NSString("Child Node")));
            }

            sourceList.Delegate = new SourceListDelegate(this);
            sourceList.DataSource = new SourceListDataSource(this);

            base.AwakeFromNib();
        }

        private class SourceListDataSource : NSOutlineViewDataSource
        {
            private MainWindowController controller;

            public SourceListDataSource(MainWindowController controller)
            {
                this.controller = controller;
            }

            public override int GetChildrenCount(NSOutlineView outlineView, NSObject item)
            {
                if(item != null)
                {
                    return (int)((Node)item).Count;
                }

                return (int)controller.rootNode.Count;
            }

            public override bool ItemExpandable(NSOutlineView outlineView, NSObject item)
            {
                if(item == null)
                {
                    return false;
                }

                return !((Node)item).Leaf;
            }

            public override NSObject GetChild(NSOutlineView outlineView, int childIndex, NSObject item)
            {
                if(item == null)
                {
                    return (Node)Runtime.GetNSObject(controller.rootNode.Children.ValueAt((uint)childIndex));
                }

                Node theItem = (Node)item;
                return (Node)Runtime.GetNSObject(theItem.Children.ValueAt((uint)childIndex));
            }

            public override NSObject GetObjectValue(NSOutlineView outlineView, NSTableColumn tableColumn, NSObject item)
            {
                if(item != null)
                {
                    return ((Node)item).Text;
                }

                return new NSString("");
            }
        }

        private class SourceListDelegate : NSOutlineViewDelegate
        {
            private MainWindowController controller;

            public SourceListDelegate(MainWindowController controller)
            {
                this.controller = controller;
            }

            public override bool IsGroupItem(NSOutlineView outlineView, NSObject item)
            {
                return (Node)item == controller.rootNode;
            }

            public override bool ShouldEditTableColumn(NSOutlineView outlineView, NSTableColumn tableColumn, NSObject item)
            {
                return true;
            }

            public override NSView GetView(NSOutlineView outlineView, NSTableColumn tableColumn, NSObject item)
            {
                if(IsGroupItem(outlineView, item))
                {
                    return outlineView.MakeView("HeaderCell", this);
                }

                var view = outlineView.MakeView("DataCell", this);
                var node = (Node)item;

                ((NSTextField)view.Subviews[1]).StringValue = node.Text;
                ((NSTextField)view.Subviews[1]).Changed += HandleChanged;

                return view;
            }

            void HandleChanged (object sender, EventArgs e)
            {
                Console.WriteLine("changed");
            }
        }

        private class Node : NSObject
        {
            private NSMutableArray children = new NSMutableArray();

            public NSMutableArray Children
            {
                get
                {
                    return children;
                }
            }

            public uint Count
            {
                get
                {
                    return Children.Count;
                }
            }

            public bool Leaf
            {
                get
                {
                    return this.Count == 0;
                }
            }

            public NSString Text { get; set; }

            public Node(NSString text)
            {
                this.Text = text;
            }
        }