在視圖內查看不更新 - Caliburn.Micro

Question

我遇到的問題是，當數據網格附加到視圖中的視圖時，它不會反映其集合的更改。 更准確地說，我在MainView中有一個SecondView。 在SecondView上我有一個datagrid，autogeneratecolumns設置為true; 首次呈現數據網格時，它會顯示相應的列和標題。 但是，當我填充附加到它的列表時，不會反映任何更改。

以下是兩個視圖及其各自視圖模型的完整代碼：MainWindowView：

<Window x:Class="MyApp.MainWindowView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:cal="http://www.caliburnproject.org"
    xmlns:views="clr-namespace:MyApp"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindowView" Height="300" Width="300">
<Grid>
    <DockPanel>
        <Menu DockPanel.Dock="Top">
            <MenuItem Header="File">
                <MenuItem Header="Open" x:Name="Open"/>
                <MenuItem Header="Exit" x:Name="Exit"/>
            </MenuItem>
        </Menu>
        <StackPanel DockPanel.Dock="Bottom">
            <views:SecondView/>
        </StackPanel>
    </DockPanel>
</Grid>

MainWindowViewModel：

namespace MyApp
{
[Export(typeof(IShell))]
internal class MainWindowViewModel : Screen, IShell
{
    Regex expression = new Regex(@"^N\d\.C\d\.D\d\.R\d:\s\s\s-\d"); //ex. "N1.C1.D2.R1:   -3"        
    SecondViewModel svm = new SecondViewModel();        
    public void Open()
    {
        Microsoft.Win32.OpenFileDialog openFile = new Microsoft.Win32.OpenFileDialog();
        openFile.Multiselect = true;
        openFile.Filter = "Text Files(*.txt)|*.txt|Log Files(*.log)|*.log|All Files(*.*)|*.*";
        openFile.Title = "Open File(s)";
        bool? userClickedOK = openFile.ShowDialog();
        string[] _fileNames = openFile.FileNames;
        if (userClickedOK == true)
        {
            if (_fileNames != null)
            {
                for (int i = 0; i < _fileNames.Length; i++)
                {
                    ValidFiles(_fileNames[i]);
                }
            }
        }
    }
    public void Exit()
    {
        App.Current.Shutdown();
    }
    /* ValidFiles() accepts a string containing a filename and creates a Streamreader that reads the file if it is not a Boxboro file.
     */
    public void ValidFiles(string filename)
    {
        string line;
        using (StreamReader sr = new StreamReader(filename))
        {
            while ((line = sr.ReadLine()) != null)
            {
                if (line.Contains("Mono Status"))
                {
                    Console.WriteLine("File(s) not supported by this parser. Please select a valid file.");
                    break;
                }
                else
                {
                    IsMatch(line);
                }
            }
        }
    }
    /* IsMatch() accepts a string "input" and determines which parsing method to send the string to, if any.
     * Strings not matching any of the initial criteria are not processed to limit overhead.
     */
    public void IsMatch(string input)
    {
        Match match = expression.Match(input);
        if (match.Success)
        {
            svm.GetData(input);
        }
    }
}

}

SecondWindowView：

<UserControl x:Class="MyApp.SecondView"
         xmlns:cal="http://www.caliburnproject.org"
         cal:Bind.Model="MyApp.SecondViewModel"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         mc:Ignorable="d" 
         d:DesignHeight="300" d:DesignWidth="300">
<Grid>
    <StackPanel>
        <DataGrid x:Name="MyList"/>
    </StackPanel>
</Grid>

SecondWindowViewModel：

namespace MyApp
{
[Export(typeof(SecondViewModel))]
class SecondViewModel:Screen
{
    Parse parse = new Parse();
    BindableCollection<MyObject> myList = new BindableCollection<MyObject>();
    MyObject myObject;
    public MyObject MyObject
    {
        get { return myObject; }
        set
        {
            myObject = value;
            NotifyOfPropertyChange(() => MyList);
        }
    }
    public BindableCollection<MyObject> MyList
    {
        get { return myList; }
        set 
        { 
            MyList = value;
            NotifyOfPropertyChange(() => MyList);
        }
    }
    public void GetData(string input)
    {
        string[] tempArray = input.Split();
        List<int> tempList = new List<int>();
        for (int i = 1; i < tempArray.Length; i++)
        {
            if (!string.IsNullOrEmpty(tempArray[i]))
            {
                tempList.Add(Convert.ToInt32(tempArray[i]));
            }
        }
        int[] tempIntArray = tempList.ToArray();
        MyObject = new MyObject(tempArray[0], tempIntArray[0], tempIntArray[1], tempIntArray[2], tempIntArray[3]);
        this.MyList.Add(MyObject);

        Console.WriteLine("MyList has " + MyList.Count.ToString() + " elements.");
        //foreach (MyObject item in MyList)
        //{
        //    Console.WriteLine(item.Location);
        //}
    }
}

}

Boostrapper：

namespace MyApp
{
    internal class AppBootStrapper : Bootstrapper<IShell>
    {
        static AppBootStrapper()
        {
            //Initializes the logger for debugging, remove or comment out in release.
            LogManager.GetLog = type => new DebugLogger(type);
        }
        private CompositionContainer container;
        protected override void BuildUp(object instance)
        {
            this.container.SatisfyImportsOnce(instance);
        }
        protected override void Configure()
        {
            this.container = 
                new CompositionContainer(
                    new AggregateCatalog(
                        AssemblySource.Instance.Select(x => new AssemblyCatalog(x)).OfType<ComposablePartCatalog>()));
            var batch = new CompositionBatch();
            batch.AddExportedValue<IWindowManager>(new WindowManager());
            batch.AddExportedValue<IEventAggregator>(new EventAggregator());
            batch.AddExportedValue(this.container);
            this.container.Compose(batch);
        }
        protected override IEnumerable<object> GetAllInstances(Type serviceType)
        {
            return this.container.GetExportedValues<object>(AttributedModelServices.GetContractName(serviceType));
        }
        //This method is required for the BootStrapper.cs to be discovered.
        protected override object GetInstance(Type serviceType, string key)
        {
            string contract = string.IsNullOrEmpty(key) ? AttributedModelServices.GetContractName(serviceType) : key;
            IEnumerable<object> exports = this.container.GetExportedValues<object>(contract);
            if (exports.Count() > 0)
            {
                return exports.First();
            }
            throw new Exception(string.Format("Could not locate any instances of contract {0}.", contract));
        }
    }
}

基於我對Caliburn.Micro的理解，每當更新observablecollection MyList（添加新項目）時，應更新具有x：name MyList的數據網格。 即使沒有數據模板，我想我會看到一個空白條目列表，其長度與MyList中的對象數量相當。 當我在MainViewModel中使用相同的代碼時，而不是在綁定到MainView的用戶控件中，我沒有問題呈現列表。 我似乎缺少一些關於在視圖中更新視圖的內容。

我應該注意，我可以通過使用Console.WriteLine（MyList.Count.ToString（））並觀察輸出窗口來驗證列表中是否有對象。 我討厭詢問這些事情，每次我這樣做都會成為一個錯字或同樣愚蠢的東西，但我已經被困在這里太久了。

注意：即使在每次迭代時拋出MyList.Refresh（），也不會發生數據網格的更改。

注意：似乎這可能會回答我的問題，但我不明白如何實現它。 也許如果其他人更好地理解它，他們可以將代碼行放在我的代碼中的適當位置並解釋其工作原理。 提前致謝。 Caliburn.Micro基於約定的綁定在嵌套視圖中不起作用？

Answer 1

嘗試這種viewmodel第一種方法 - 我懷疑你的內部視圖沒有被綁定（CM在應用約定時不會跨越控制邊界，例如它不會對嵌套用戶控件應用約定）

<Window x:Class="MyApp.MainWindowView"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:cal="http://www.caliburnproject.org"
    xmlns:views="clr-namespace:MyApp"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindowView" Height="300" Width="300">
<Grid>
    <DockPanel>
        <Menu DockPanel.Dock="Top">
            <MenuItem Header="File">
                <MenuItem Header="Open" x:Name="Open"/>
                <MenuItem Header="Exit" x:Name="Exit"/>
            </MenuItem>
        </Menu>
        <StackPanel DockPanel.Dock="Bottom">
            <!-- Use ContentControl for sub-views, CM will do it's magic if you bind to the VM property using the standard conventions -->
            <ContentControl x:Name="SecondView" />
        </StackPanel>
    </DockPanel>
</Grid>

然后在你的主要：

internal class MainWindowViewModel : Screen, IShell
{
    Regex expression = new Regex(@"^N\d\.C\d\.D\d\.R\d:\s\s\s-\d"); //ex. "N1.C1.D2.R1:   -3"      
    // Declare your second VM as a property so you can bind to it via CM conventions  
    public SecondViewModel SecondView 
    { 
        get { return _secondView; } 
        set 
        {
            _secondView = value;
            NotifyOfPropertyChange(() => SecondView);
        }
    }

    public MainWindowViewModel()
    {
        SecondView = new SecondViewModel();
    }

CM將自動將正確的視圖注入內容控件模板並設置datacontext

或者，您可以使用Bind.Model將VM實例綁定到視圖，這更像是一種視圖優先方法

   <StackPanel DockPanel.Dock="Bottom">
        <views:SecondView cal:Bind.Model="{Binding SecondView}" />
    </StackPanel>

（我認為它是Bind.Model而不是View.Model，但我經常把兩者搞混，所以Bind.Model失敗了，試試View.Model）