Question

我正在开发一个使用Silicon Labs SDK的项目。在为SDK创建包装器之后，我创建了一个WPF项目来可视化SDK中的一些结果。我的第一个测试是使用GetNumDevices函数。我的WPF知识不是很强，所以对任何让你眼睛流血的事感到抱歉，但是为了演示让我告诉你我有什么。首先是我正在讨论的API方法。

[DllImport("CP210xManufacturing.dll", CallingConvention = CallingConvention.StdCall)]
public static extern CP210x_STATUS CP210x_GetNumDevices(ref int lpdwNumDevices);

而不是制作2个标签和1个按钮来显示这个方法，我决定让用户控制。

CP210UserControl.xaml

<UserControl x:Class="SiliconLabsRosettaStone.CP210UserControl"
             x:Name="panel"
             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="50" d:DesignWidth="300"
             DataContext="{Binding ElementName=panel}">
    <Border BorderBrush="DarkGreen" BorderThickness="3" Margin="2">
        <Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="Auto"/>
                <ColumnDefinition />
                <ColumnDefinition Width="75"/>
            </Grid.ColumnDefinitions>

            <TextBlock Text="{Binding Caption}" Margin="3,0" />
            <Border Grid.Column="1" BorderBrush="Black" BorderThickness="2" Margin="3,0">
                <TextBlock x:Name="responseTextBlock" Text="{Binding Response}" />
            </Border>
            <Button Grid.Column="2" Content="Execute" Click="Button_Click" Margin="3,0" />
        </Grid>
    </Border>
</UserControl>

CP210UserControl.xaml.cs

public partial class CP210UserControl : UserControl
{
    public CP210UserControl()
    {
        InitializeComponent();
    }
    public void SetupUserControl(Func<CP210UserControl, CP210x_STATUS> function)
    {
        this.cp210Function = function;
    }
    private void Button_Click(object sender, RoutedEventArgs e)
    {
        CP210x_STATUS response = cp210Function(this);
        this.responseTextBlock.Background = response == CP210x_STATUS.CP210x_SUCCESS ? null : new SolidColorBrush(Colors.Pink);
    }

    public string Caption
    {
        get { return (string)GetValue(CaptionProperty); }
        set { SetValue(CaptionProperty, value); }
    }

    public string Response
    {
        get { return (string)GetValue(ResponseProperty); }
        set { SetValue(ResponseProperty, value); }
    }

    public static readonly DependencyProperty CaptionProperty = DependencyProperty.Register("Caption", typeof(string), typeof(CP210UserControl), new PropertyMetadata("CP210x"));
    public static readonly DependencyProperty ResponseProperty = DependencyProperty.Register("Response", typeof(string), typeof(CP210UserControl), new PropertyMetadata(""));

    private Func<CP210UserControl, CP210x_STATUS> cp210Function;
}

这是因为它的使用而我有疑问的文件。

这就是我在主窗口中使用它的方式

MainWindow.xaml

<StackPanel>
    <local:CP210UserControl x:Name="cpGetNumDevices" Grid.Row="1" Grid.ColumnSpan="3" Caption="CP210x_GetNumDevices" />
</StackPanel>

现在我讨厌的部分。我怎么联系起来：/

MainWindow.xaml.cs

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        cpGetNumDevices.SetupUserControl(getNumberDevices);
    }
    private CP210x_STATUS getNumberDevices(CP210UserControl control)
    {
        int devices = 0;
        var result = CP210xWrapper.CP210x_GetNumDevices(ref devices);
        control.Response = string.Format("Number Of Devices:{0}", devices);
        return result;
    }

我认为我可以让xaml看起来像这样

    <local:CP210UserControl x:Name="cpGetNumDevices" Grid.Row="1" Grid.ColumnSpan="3" Caption="CP210x_GetNumDevices" cp210Function="getNumberDevices" />

如果我将用户控件更改为此。

    public Func<CP210UserControl, CP210x_STATUS> cp210Function
    {
        get { return (Func<CP210UserControl, CP210x_STATUS>)GetValue(cp210FunctionProperty); }
        set { SetValue(cp210FunctionProperty, value); }
    }

    public static readonly DependencyProperty cp210FunctionProperty = DependencyProperty.Register("cp210Function", typeof(Func<CP210UserControl, CP210x_STATUS>), typeof(CP210UserControl), new PropertyMetadata(null));

但是当我运行该程序时，我收到此错误

A first chance exception of type 'System.Windows.Markup.XamlParseException' occurred in PresentationFramework.dll
Additional information: 'Func`2' type does not have a public TypeConverter class.  Error at Line 7 Position 122.

那我怎么才能说出TypeConverter？它甚至可能吗？

修改

这基本上是我最终的游戏。

What I am shooting for

Answer 1

你的班级结构对我来说似乎很尴尬。

UI不是与任何外部库进行任何交互的正确位置。

如果你正在使用WPF，你真的需要拥抱The WPF Mentality。

这就是我在WPF中的表现：

<UserControl x:Class="SiliconLabsRosettaStone.CP210UserControl"
             ...>
    <!-- ... Omitted for brevity -->

            <TextBlock Text="{Binding Caption}" ... />

            <TextBlock Text="{Binding NumberOfDevices}" />

            <Button Content="Execute" Click="Button_Click" ... />

    <!-- ... -->
</UserControl>

用户控制代码背后：

public class CP210UserControl: UserControl
{
   public CP210UserControl()
   {
       InitializeComponent();
   }

   private void Button_Click(object sender, RoutedEventArgs e)
   {
      var VM = DataContext as MyViewModel;
      if (VM != null)
      {
          //Correct uses of Code-Behind:

          //1 - Call ViewModel Methods:
          var response = VM.GetNumberDevices();

          //2 - UI-specific code which does not contain business logic:
          responseTextBlock.Background = response ? null : Brushes.Pink;
      }
   }
}

窗口：

<Window ....>
   <local:CP210UserControl/>
</Window>

代码背后：

public class MainWindow: Window
{
    public MainWindow()
    {
       InitializeComponent();
       DataContext = new MyViewModel();
    }
}

视图模型：

public class MyViewModel: INotifyPropertyChanged
{
   public string Caption {get;set;} //NotifyPropertyChanged() required.

   public string NumberOfDevices {get;set;} //NotifyPropertyChanged() required.

   public bool GetNumberDevices()
   {
       int devices = 0;
       var result = CP210xWrapper.CP210x_GetNumDevices(ref devices);
       NumberOfDevices = string.Format("Number Of Devices:{0}", devices);

       return result == CP210x_STATUS.CP210x_SUCCESS;
   }

   //INotifyPropertyChanged implementation omitted for brevity.
}

不需要奇怪的Func。
不需要DependencyProperties。
简单，简单的属性和INotifyPropertyChanged 。这就是你在WPF中编码的方式。
以这种方式使用代码完全有效，只是为了调用ViewModel中的方法，而不是将实际的逻辑和行为放在代码中。
WPF Rocks
如果您需要进一步的帮助，请告诉我。

如何将委托放在UserControl中

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