Question

EditingModel.cs：

private ObservableCollection<string> color;
public ObservableCollection<string> Color
{
    get { return color; }
    set
    {
        color = value;
        NotifyPropertyChanged("Color");
    }
}
private ObservableCollection<string> shapes;
public ObservableCollection<string> Shapes
{
    get { return shapes; }
    set
    {
        shapes = value;
        NotifyPropertyChanged("Shapes");
    }
}
private ObservableCollection<string> size;
public ObservableCollection<string> Size
{
    get { return size; }
    set
    {
        size = value;
        NotifyPropertyChanged("Size");
    }
}

EditingsViewModel.cs：

private string selectedcolor;
public string SelectedColor
{
    get { return selectedcolor; }
    set
    {
        if (value != selectedcolor)
        {
            selectedcolor = value; NotifyPropertyChanged("SelectedColor");
        }
    }
}
private string selectedshapes;
public string SelectedShapes
{
    get { return selectedshapes; }
    set
    {
        if (value != selectedshapes)
        {
            selectedshapes = value; NotifyPropertyChanged("SelectedShapes");
        }
    }
}
private string selectedsize;
public string SelectedSize
{
    get { return selectedsize; }
    set
    {
        if (value != selectedsize)
        {
            selectedsize = value; NotifyPropertyChanged("SelectedSize");
        }
    }
}

XML文档（XML文档的名称为EditingsValue.xml）

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE MYEDITINGS[]>
<MYEDITINGS>
  <Group name="GeneralEditings">
     <EditingsName name="COLOR" value="red"/>
     <EditingsName name="SHAPES" value="circle"/>
     <EditingsName name="SIZE" value="medium"/>
     <EditingsName name="FILE PATH" value="C:\ProgramFiles"/>
  </Group>
</MYEDITINGS>

EditingsView.xaml：

<ComboBox SelectedValue="{Binding SelectedColor,Mode=TwoWay}" Height="25" Width="150"    HorizontalContentAlignment="Right"  VerticalAlignment="Center"  ItemsSource="{Binding Color}"/ >
<ComboBox SelectedValue="{Binding SelectedShapes,Mode=TwoWay}" Height="25" Width="150"   HorizontalContentAlignment="Right"  VerticalAlignment="Center"  ItemsSource="{Binding Shapes}"/ >
<ComboBox SelectedValue="{Binding SelectedSize,Mode=TwoWay}" Height="25" Width="150"    HorizontalContentAlignment="Right"  VerticalAlignment="Center"  ItemsSource="{Binding Size}" />
<TextBox     Height="26"  Grid.Column="3"  IsReadOnly="True" TextAlignment="Right" VerticalContentAlignment="Center"  HorizontalAlignment="Left" VerticalAlignment="Center"  Width="150"   Text="{Binding ElementName=Mygroups, Path=DataContext.FolderPath,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}"  />
<Button   KeyboardNavigation.TabIndex="2"  Grid.Column="4"  Content="Browse"    Height="29" VerticalAlignment="Bottom"   MinWidth="45"   Command="{Binding  ElementName=Mygeoups,Path=DataContext.FolderCommand}" CommandParameter="{Binding}" />

在上面的代码中，我使用 SelectedIndex 为组合框设置默认值，然后允许用户选择自己的值。然后，如上所述，我在 XML文档中写入用户的选定值。到目前为止，一切正常。但是现在我的要求是，如果再次打开我的应用程序，我不应该在组合框和文本框中获取默认值，而是应该阅读xml文档，并在组合框和文本框中显示该值。

如何使用MVVM（wpf）实现此目的。谁能帮帮我。

谢谢。

Answer 1

我认为，这对您有帮助

对于 EditingsViewModel.cs 构造函数，请读取Xml文件，并将值分配给模型

  public EditingsViewModel()
    {
           ComboBoxModel = new EditingModel();

        //Xml Path
        string xmlpath = @"D:\MyDocument.xml";

        var doc = new XmlDocument();
        doc.Load(xmlpath);
        XmlNode colorNode = doc.SelectSingleNode(@"/MYEDITINGS/Group/EditingsName[@name = 'COLOR']/@value");
        XmlNode shapesNode = doc.SelectSingleNode(@"/MYEDITINGS/Group/EditingsName[@name = 'SHAPES']/@value");
        XmlNode sizeNode = doc.SelectSingleNode(@"/MYEDITINGS/Group/EditingsName[@name = 'SIZE']/@value");
        XmlNode filePathNode = doc.SelectSingleNode(@"/MYEDITINGS/Group/EditingsName[@name = 'FILE PATH']/@value");

        //Binding the Color to the Color Property
        var observableColors = new System.Collections.ObjectModel.ObservableCollection<string>() { "red","yellow","green"};
        ComboBoxModel.Color = observableColors;

        //Binding the Shapes to the Shape Property
        var observableShapes = new System.Collections.ObjectModel.ObservableCollection<string>() { "circle", "Triangle", "Rectangle" };
        ComboBoxModel.Shapes = observableShapes;

        //Binding the Size to the Size Property
        var observableSize = new System.Collections.ObjectModel.ObservableCollection<string>() { "medium", "high", "low" };
        ComboBoxModel.Size = observableSize;

        //Assign the Color Default vlaue from the Xml Document 
        SelectedColor = colorNode.Value;

        //Assign the Shape Default vlaue from the Xml Document 
        SelectedShapes = shapesNode.Value;

        //Assign the Size  Default vlaue from the Xml Document 
        SelectedSize = sizeNode.Value;

        //Assign the FilePath Default vlaue from the Xml Document 
        FolderPath = filePathNode.Value;
    }

EditingsView.xaml -删除选定的索引属性

   <ComboBox SelectedValue="{Binding SelectedColor,Mode=TwoWay}" Height="25" Width="150"    HorizontalContentAlignment="Right"  VerticalAlignment="Center"  ItemsSource="{Binding ComboBoxModel.Color}"/>
    <ComboBox SelectedValue="{Binding SelectedShapes,Mode=TwoWay}" Height="25" Width="150"   HorizontalContentAlignment="Right"  VerticalAlignment="Center"  ItemsSource="{Binding ComboBoxModel.Shapes}"/>
    <ComboBox SelectedValue="{Binding SelectedSize,Mode=TwoWay}" Height="25" Width="150"    HorizontalContentAlignment="Right"  VerticalAlignment="Center"  ItemsSource="{Binding ComboBoxModel.Size}" />
    <TextBox Name="Mygroups"    Height="26"  Grid.Column="3"  IsReadOnly="True" TextAlignment="Right" VerticalContentAlignment="Center"  HorizontalAlignment="Left" VerticalAlignment="Center"  Width="150"   Text="{Binding ElementName=Mygroups, Path=DataContext.FolderPath,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay}"  />
    <Button   KeyboardNavigation.TabIndex="2"  Grid.Column="4"  Content="Browse"    Height="29" VerticalAlignment="Bottom"   MinWidth="45"   Command="{Binding  ElementName=Mygeoups,Path=DataContext.FolderCommand}" CommandParameter="{Binding}" />

如何读取XML文档并将其值附加到组合框和文本框

1 个答案: