C# 在c中使用MVVM（模型-视图-视图-模型）的WPF OpenFileDialog#_C#_Wpf_Mvvm

C# 在c中使用MVVM（模型-视图-视图-模型）的WPF OpenFileDialog#

c# wpf mvvm

C# 在c中使用MVVM（模型-视图-视图-模型）的WPF OpenFileDialog#,c#,wpf,mvvm,C#,Wpf,Mvvm,如何在c#中使用MVVM（模型-视图-视图-模型）编写WPF OpenFileDialog？我已经访问了一些关于这个OpenFileDialog的网站，但是我没有对它有清楚的了解。这是我的密码在视图中.xaml： <Window.... xmlns:VM="clr-namespace:myproject.myViewModel" ... > <Window.DataContext><VM:myViewModel/> </Window.Dat

如何在c#中使用MVVM（模型-视图-视图-模型）编写WPF OpenFileDialog？我已经访问了一些关于这个OpenFileDialog的网站，但是我没有对它有清楚的了解。这是我的密码

在视图中.xaml：

<Window....  xmlns:VM="clr-namespace:myproject.myViewModel"
  ...  >
<Window.DataContext><VM:myViewModel/>

</Window.DataContext>
 <ItemsControl ItemsSource="{Binding mygroup}" >
        <ItemsControl.ItemTemplate >
        <DataTemplate>

                 <Grid >....

                       <TextBlock Text="Color"  Margin="20" VerticalAlignment="Center"/>
                        <ComboBox   KeyboardNavigation.TabIndex="0" Grid.Column="1" Margin="45,10,10,10" Height="30" Width="200" ItemsSource="{Binding Color}"   />
                        <TextBlock Text="Shapes" Grid.Row="1"  VerticalAlignment="Center"  />

                        <ComboBox KeyboardNavigation.TabIndex="3" Grid.Column="1" Grid.Row="1" Height="20" Width="150" SelectedIndex="0"   HorizontalContentAlignment="Right" 
                      VerticalAlignment="Center"  ItemsSource="{Binding Shapes}">
                                                            </ComboBox>

<TextBlock Text="Open Files "  VerticalAlignment="Center"      Grid.Row="0"  Grid.Column="2" Margin="10"    />
                                <TextBox  Grid.Column="3" Text="" Height="30" Grid.Row="0"   IsReadOnly="True" 
                        TextAlignment="Right" VerticalContentAlignment="Center" Width="200" />                                    <Button  Grid.Column="4"  Content="Browse"    Height="30" VerticalAlignment="Bottom"   MinWidth="41" />
                   </Grid>

 </Window>

namespace Myproject.Models
{
  public class ProjectModel : INotifyPropertyChanged
  {
    private ObservableCollection<string> color;
    private ObservableCollection<string> shapes;
    public ObservableCollection<string> Color
{
  get { return color; }
  set
  {
    color = value;
    NotifyPropertyChanged("Color");
  }
}

public ObservableCollection<string> Shapes
{
  get { return shapes; }
  set
  {
    shapes = value;
    NotifyPropertyChanged("Shapes");
  }
}


#region INotifyPropertyChanged Members

public event PropertyChangedEventHandler PropertyChanged;

#endregion

#region Private Helpers

private void NotifyPropertyChanged(string propertyName)
{
  if (PropertyChanged != null)
  {
    PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
  }
}

#endregion


 }
}

namespace MyProject.ViewModels    
{
  public class myProjectViewModel : INotifyPropertyChanged
  {
    private ObservableCollection<myprojectmodel> mygroup;

public ObservableCollection<myprojectmodel> Mygroup
{
  get => this.mygroup;
  set
  {
    if (Equals(value, this.mygroup)) return;
    this.mygroup = value;
    OnPropertyChanged();
  }
}

public ProjectViewModel()
{
  Mygroup = new ObservableCollection<myprojectmodel>();
  List<string> lstColor = new List<string>();
  lstCity = new List<string> {"Pink", "Blue", "Red"};
  List<string> lstShapes = new List<string>();
  lstTemperature = new List<string> {"Rectangle", "Triangle", "Circle"};
   Mygroup.Add(
    new ProjectModel
    {
      Color= new ObservableCollection<string>(lstColor),
      Shapes = new ObservableCollection<string>(lstShapes),
      });
}

public event PropertyChangedEventHandler PropertyChanged;   

protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
  this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}


 }
}


....

在Model.cs中：

<Window....  xmlns:VM="clr-namespace:myproject.myViewModel"
  ...  >
<Window.DataContext><VM:myViewModel/>

</Window.DataContext>
 <ItemsControl ItemsSource="{Binding mygroup}" >
        <ItemsControl.ItemTemplate >
        <DataTemplate>

                 <Grid >....

                       <TextBlock Text="Color"  Margin="20" VerticalAlignment="Center"/>
                        <ComboBox   KeyboardNavigation.TabIndex="0" Grid.Column="1" Margin="45,10,10,10" Height="30" Width="200" ItemsSource="{Binding Color}"   />
                        <TextBlock Text="Shapes" Grid.Row="1"  VerticalAlignment="Center"  />

                        <ComboBox KeyboardNavigation.TabIndex="3" Grid.Column="1" Grid.Row="1" Height="20" Width="150" SelectedIndex="0"   HorizontalContentAlignment="Right" 
                      VerticalAlignment="Center"  ItemsSource="{Binding Shapes}">
                                                            </ComboBox>

<TextBlock Text="Open Files "  VerticalAlignment="Center"      Grid.Row="0"  Grid.Column="2" Margin="10"    />
                                <TextBox  Grid.Column="3" Text="" Height="30" Grid.Row="0"   IsReadOnly="True" 
                        TextAlignment="Right" VerticalContentAlignment="Center" Width="200" />                                    <Button  Grid.Column="4"  Content="Browse"    Height="30" VerticalAlignment="Bottom"   MinWidth="41" />
                   </Grid>

 </Window>

namespace Myproject.Models
{
  public class ProjectModel : INotifyPropertyChanged
  {
    private ObservableCollection<string> color;
    private ObservableCollection<string> shapes;
    public ObservableCollection<string> Color
{
  get { return color; }
  set
  {
    color = value;
    NotifyPropertyChanged("Color");
  }
}

public ObservableCollection<string> Shapes
{
  get { return shapes; }
  set
  {
    shapes = value;
    NotifyPropertyChanged("Shapes");
  }
}


#region INotifyPropertyChanged Members

public event PropertyChangedEventHandler PropertyChanged;

#endregion

#region Private Helpers

private void NotifyPropertyChanged(string propertyName)
{
  if (PropertyChanged != null)
  {
    PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
  }
}

#endregion


 }
}

namespace MyProject.ViewModels    
{
  public class myProjectViewModel : INotifyPropertyChanged
  {
    private ObservableCollection<myprojectmodel> mygroup;

public ObservableCollection<myprojectmodel> Mygroup
{
  get => this.mygroup;
  set
  {
    if (Equals(value, this.mygroup)) return;
    this.mygroup = value;
    OnPropertyChanged();
  }
}

public ProjectViewModel()
{
  Mygroup = new ObservableCollection<myprojectmodel>();
  List<string> lstColor = new List<string>();
  lstCity = new List<string> {"Pink", "Blue", "Red"};
  List<string> lstShapes = new List<string>();
  lstTemperature = new List<string> {"Rectangle", "Triangle", "Circle"};
   Mygroup.Add(
    new ProjectModel
    {
      Color= new ObservableCollection<string>(lstColor),
      Shapes = new ObservableCollection<string>(lstShapes),
      });
}

public event PropertyChangedEventHandler PropertyChanged;   

protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
  this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}


 }
}

名称空间Myproject.Models
{
公共类项目模型：INotifyPropertyChanged
{
私人可见采集颜色；
私有可观察集合形状；
公共可见采集颜色
{
获取{返回颜色；}
设置
{
颜色=值；
NotifyPropertyChanged（“颜色”）；
}
}
公共可观测集合形状
{
获取{返回形状；}
设置
{
形状=价值；
NotifyPropertyChanged（“形状”）；
}
}
#区域INotifyProperty更改成员
公共事件属性更改事件处理程序属性更改；
#端区
#地区私人助理
私有void NotifyPropertyChanged（字符串propertyName）
{
if（PropertyChanged！=null）
{
PropertyChanged（这是新的PropertyChangedEventArgs（propertyName））；
}
}
#端区
}
}

在视图模型.cs中：

<Window....  xmlns:VM="clr-namespace:myproject.myViewModel"
  ...  >
<Window.DataContext><VM:myViewModel/>

</Window.DataContext>
 <ItemsControl ItemsSource="{Binding mygroup}" >
        <ItemsControl.ItemTemplate >
        <DataTemplate>

                 <Grid >....

                       <TextBlock Text="Color"  Margin="20" VerticalAlignment="Center"/>
                        <ComboBox   KeyboardNavigation.TabIndex="0" Grid.Column="1" Margin="45,10,10,10" Height="30" Width="200" ItemsSource="{Binding Color}"   />
                        <TextBlock Text="Shapes" Grid.Row="1"  VerticalAlignment="Center"  />

                        <ComboBox KeyboardNavigation.TabIndex="3" Grid.Column="1" Grid.Row="1" Height="20" Width="150" SelectedIndex="0"   HorizontalContentAlignment="Right" 
                      VerticalAlignment="Center"  ItemsSource="{Binding Shapes}">
                                                            </ComboBox>

<TextBlock Text="Open Files "  VerticalAlignment="Center"      Grid.Row="0"  Grid.Column="2" Margin="10"    />
                                <TextBox  Grid.Column="3" Text="" Height="30" Grid.Row="0"   IsReadOnly="True" 
                        TextAlignment="Right" VerticalContentAlignment="Center" Width="200" />                                    <Button  Grid.Column="4"  Content="Browse"    Height="30" VerticalAlignment="Bottom"   MinWidth="41" />
                   </Grid>

 </Window>

namespace Myproject.Models
{
  public class ProjectModel : INotifyPropertyChanged
  {
    private ObservableCollection<string> color;
    private ObservableCollection<string> shapes;
    public ObservableCollection<string> Color
{
  get { return color; }
  set
  {
    color = value;
    NotifyPropertyChanged("Color");
  }
}

public ObservableCollection<string> Shapes
{
  get { return shapes; }
  set
  {
    shapes = value;
    NotifyPropertyChanged("Shapes");
  }
}


#region INotifyPropertyChanged Members

public event PropertyChangedEventHandler PropertyChanged;

#endregion

#region Private Helpers

private void NotifyPropertyChanged(string propertyName)
{
  if (PropertyChanged != null)
  {
    PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
  }
}

#endregion


 }
}

namespace MyProject.ViewModels    
{
  public class myProjectViewModel : INotifyPropertyChanged
  {
    private ObservableCollection<myprojectmodel> mygroup;

public ObservableCollection<myprojectmodel> Mygroup
{
  get => this.mygroup;
  set
  {
    if (Equals(value, this.mygroup)) return;
    this.mygroup = value;
    OnPropertyChanged();
  }
}

public ProjectViewModel()
{
  Mygroup = new ObservableCollection<myprojectmodel>();
  List<string> lstColor = new List<string>();
  lstCity = new List<string> {"Pink", "Blue", "Red"};
  List<string> lstShapes = new List<string>();
  lstTemperature = new List<string> {"Rectangle", "Triangle", "Circle"};
   Mygroup.Add(
    new ProjectModel
    {
      Color= new ObservableCollection<string>(lstColor),
      Shapes = new ObservableCollection<string>(lstShapes),
      });
}

public event PropertyChangedEventHandler PropertyChanged;   

protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
  this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}


 }
}

namespace MyProject.ViewModels
{
公共类myProjectViewModel:INotifyPropertyChanged
{
私人可观察收集mygroup；
公共可观测集合Mygroup
{
get=>this.mygroup；
设置
{
if（等于（value，this.mygroup））返回；
this.mygroup=值；
OnPropertyChanged（）；
}
}
公共项目视图模型（）
{
Mygroup=新的ObservableCollection（）；
List lstColor=新列表（）；
lstCity=新列表{“粉色”、“蓝色”、“红色”}；
List lstShapes=新列表（）；
lstTemperature=新列表{“矩形”、“三角形”、“圆形”}；
Mygroup.Add(
新项目模型
{
颜色=新的可见光采集（LSTCLOR），
形状=新的可观察集合（lstShapes），
});
}
公共事件属性更改事件处理程序属性更改；
受保护的虚拟void OnPropertyChanged（[CallerMemberName]字符串propertyName=null）
{
this.PropertyChanged？.Invoke（this，newpropertychangedeventargs（propertyName））；
}
}
}

我应该如何编写代码来获取OpenFileDialog。我已经看到了这个链接，但我不知道如何为我上面的代码编写它。

请有人帮我编辑代码以获取OpenFileDailog。

在我看来，这种东西不属于ViewModel。这是特定于视图的逻辑。视图单独处理用户输入，然后将其发送到ViewModel。ViewModel从不要求视图执行某些操作。这将反转依赖链并将ViewModel与视图耦合。依赖项必须如下所示：查看-->视图模型-->模型。ViewModel甚至不知道视图的类型，也不知道是否存在视图

必须从视图中打开对话框，然后将结果发送到视图模型。为此，您可以在代码中创建一个简单的事件处理程序，并将其附加到按钮的单击事件。获取拾取的文件并使用ICommand调用例如打开文件操作。这就是MVVM（或MVP）。将视图的关注点与模型分开

MainWindow.xaml：

<Window x:Class="WpfOpenDialogExample.OpenFileDialogSample"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="OpenFileDialogSample" Height="300" Width="300">
    <Window.DataContext>
        <ViewModel />
    </Window.DataContext>

    <Grid>
        <Button Name="ShowFilePickerButton" Click="ShowFilePicker_OnClick" Content="Open file" />
    </Grid>
</Window>

ViewModel.cs：

public ICommand OpenFileCommand { get => new RelayCommand(OpenFile, CanOpenFile); }  

private void OpenFile(string filePath)
{
   ...
}

private bool CanOpenFile(string filePath)
{
   return File.Exists(filePath);
}

public ICommand OpenFolderCommand { get => new RelayCommand(OpenFolder, CanOpenFolder); }

private void OpenFolder(string folderPath)
{
   ...
}

private bool CanOpenFolder(string folderPath)
{
   return Directory.Exists(filePath);
}

RelayCommand.cs：

using System;
using System.Windows.Input;

namespace WpfOpenDialogExample
{
  /// <summary>
  /// An implementation independent ICommand implementation.
  /// Enables instant creation of an ICommand without implementing the ICommand interface for each command.
  /// The individual Execute() an CanExecute() members are suplied via delegates.
  /// <seealso cref="System.Windows.Input.ICommand"/>
  /// </summary>
  /// <remarks>The type of <c>RelaisCommand</c> actually is a <see cref="System.Windows.Input.ICommand"/></remarks>
    public class RelayCommand : ICommand
    {
      /// <summary>
      /// Default constructor to declare the concrete implementation of Execute(object):void and CanExecute(object) : bool
      /// </summary>
      /// <param name="executeDelegate">Delegate referencing the execution context method. 
      /// Delegate signature: delegate(object):void</param>
      /// <param name="canExecuteDelegate">Delegate referencing the canExecute context method.
      /// Delegate signature: delegate(object):bool</param>
      public RelayCommand(Action<object> executeDelegate , Predicate<object> canExecuteDelegate)
      {
        this.executeDelegate = executeDelegate;
        this.canExecuteDelegate = canExecuteDelegate;
      }

      /// <summary>
      /// Invokes the custom <c>canExecuteDelegate</c> which should check wether the command can be executed.
      /// </summary>
      /// <param name="parameter">Optional parameter of type <see cref="System.Object"/></param>
      /// <returns>Expected to return tue, when the preconditions meet the requirements and therefore the command stored in <c>executeDelegate</c> can execute.
      /// Expected to return fals when command execution is not possible.</returns>
      public bool CanExecute(object parameter)
      {
        if (this.canExecuteDelegate != null)
        {
          return this.canExecuteDelegate(parameter);
        }
        return false;
      }

      /// <summary>
      /// Invokes the custom <c>executeDelegate</c>, which references the command to execute.
      /// </summary>
      /// <param name="parameter">Optional parameter of type <see cref="System.Object"/></param>
      public void Execute(object parameter)
      {
        if (this.executeDelegate != null)
          this.executeDelegate(parameter);
      }

      /// <summary>
      /// The event is triggered every time the conditions regarding the command have changed. This occures when <c>InvalidateRequerySuggested()</c> gets explicitly or implicitly called.
      /// Triggering this event usually results in an invokation of <c>CanExecute(object):bool</c> to check if the occured change has made command execution possible.
      /// The <see cref="System.Windows.Input.CommandManager"/> holds a weakrefernce to the observer.
      /// </summary>
      public event EventHandler CanExecuteChanged
      {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
      }

      private readonly Action<object> executeDelegate;
      private readonly Predicate<object> canExecuteDelegate;
    }
}

使用系统；
使用System.Windows.Input；
命名空间wpfpendialoge示例
{
/// 
///独立于实现的ICommand实现。
///支持即时创建ICommand，而无需为每个命令实现ICommand接口。
///单个Execute（）和CanExecute（）成员通过委托提供。
/// 
/// 
///relaicommand的类型实际上是
公共类中继命令：ICommand
{
/// 
///声明Execute（object）：void和CanExecute（object）：bool的具体实现的默认构造函数
/// 
///委托引用执行上下文方法。
///委托签名：委托（对象）：无效
///引用canExecute上下文方法的委托。
///委托签名：委托（对象）：bool
公共RelayCommand（Action executeDelegate、谓词canExecuteDelegate）
{
this.executeelegate=executeelegate；
this.canExecuteDelegate=canExecuteDelegate；
}
/// 
///调用自定义canExecuteDelegate，该自定义canExecuteDelegate应检查是否可以执行该命令。
/// 
///类型的可选参数
///当前提条件满足要求时，预计返回tue，因此可以执行ExecuteElegate中存储的命令。
///当无法执行命令时，应返回FAL。
公共布尔CanExecute（对象参数）
{
如果（this.canExecuteDelegate！=null）
{
返回此.canExecuteDelegate（参数）；
}
返回false；
}
/// 
///调用自定义ExecuteElegate，它引用要执行的命令。
/// 
///类型的可选参数
public void Execute（对象参数）
{
if（this.executeelegate！=null）
此.executeElegate（参数）；
}
/// 
///每次有关该命令的条件发生更改时都会触发该事件。当显式或隐式调用InvalidateRequestSuggested（）时会发生这种情况。
///触发此事件通常会导致调用CanExecute（object）：bool以检查发生的更改是否使命令执行成为可能。
///他对观察家怀有一种软弱的感情。
/// 
公共事件事件处理程序CanExecuteChanged
{
添加{CommandManager.RequerySuggested+=value；}
删除{CommandManager.RequerySuggested-=value；}
}
私有的