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我有一个EstimateInformationTable带有CATEGORY,的数据库DESCRIPTION。共 100 条记录。有 100Descriptions和 10 Categories，所以显然Categories它们不止一次使用。例子：

+----------+-------------+
| CATEGORY | DESCRIPTION |
+----------+-------------+
| ACC      | DescAAAA    |
| ACC      | DescBBBB    |
| BMX      | DescCCCC    |
+----------+-------------+

我想使用第一个 ComboBox (CATEGORY) 来限制第二个 ComboBox (DESCRIPTION) 中的选择。

我有两个 ComboBoxes 绑定到两个 DataSet TableAdaptors。每个都TableAdaptor返回一个简单但不同的模式。

组合框1：

SELECT DISTINCT CATEGORY
FROM EstimateInformationTable
ORDER BY CATEGORY

组合框2：

SELECT DESCRIPTION
FROM EstimateInformationTable
WHERE (CATEGORY = @Category)
ORDER BY DESCRIPTION

我可以使用一个 extra 让它在 CodeBehind 中工作ButtonClickEvent，但显然这最终不是我想要的。

我想使用 MVVM 和正确的通知属性（如果需要这样做），以便更改类别组合框更新描述组合框。

这必须一直做，但我对这很多都不熟悉。我正在取得进展，但我很难理解这一点。这是一个自我强加的学习练习，所以请随意为我简化解释。谢谢，迈克

XAML：

<Page
      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" 
      xmlns:local="clr-namespace:gobo.Pages"
      xmlns:gobo="clr-namespace:gobo" x:Class="gobo.Pages.TESTSTUFF01"
      xmlns:vm="clr-namespace:gobo.ViewModel"
      mc:Ignorable="d" 

      Title="TESTSTUFF01" Loaded="Page_Loaded">
    <Page.Resources>
        <vm:CategoryChangedViewModel x:Key="CategoryChangedViewModel"/>
        <gobo:gobo2018DataSet1 x:Key="gobo2018DataSet1"/>
        <CollectionViewSource x:Key="estimateInformationTableViewSource" Source="{Binding EstimateInformationTable, Source={StaticResource gobo2018DataSet1}}"/>
        <gobo:gobo2018EstimateInformationTableDescriptionDataSet x:Key="gobo2018EstimateInformationTableDescriptionDataSet"/>
        <CollectionViewSource x:Key="estimateInformationTableViewSource1" Source="{Binding EstimateInformationTable, Source={StaticResource gobo2018EstimateInformationTableDescriptionDataSet}}"/>
    </Page.Resources>


    <Page.Background>
        <LinearGradientBrush EndPoint="0.5,1" MappingMode="RelativeToBoundingBox" StartPoint="0.5,0">
            <GradientStop Color="Black" Offset="0"/>
            <GradientStop Color="Red" Offset="1"/>
        </LinearGradientBrush>
    </Page.Background>

    <StackPanel Orientation="Vertical" >
        <Label Content="TEST STUFF 01 Tab Page1" VerticalAlignment="Top" Background="{x:Null}"/>
        <Button Content="Change Description contents" Click="Button_Click"/>
        <Grid x:Name="grid1" DataContext="{StaticResource estimateInformationTableViewSource}" HorizontalAlignment="Left" VerticalAlignment="Top">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="Auto"/>
                <ColumnDefinition Width="Auto"/>
            </Grid.ColumnDefinitions>
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto"/>
            </Grid.RowDefinitions>
            <Label Content="CATEGORY:" Grid.Column="0" HorizontalAlignment="Left" Margin="3" Grid.Row="0" VerticalAlignment="Center"/>

            <ComboBox x:Name="cATEGORYComboBox" Grid.Column="1" DisplayMemberPath="CATEGORY" HorizontalAlignment="Left" Height="Auto" Margin="3" Grid.Row="0" VerticalAlignment="Center" Width="120" 
                      ItemsSource="{Binding}" 
                      SelectedIndex="{Binding Category, Source={StaticResource CategoryChangedViewModel}}">
                <ComboBox.ItemsPanel>
                    <ItemsPanelTemplate>
                        <VirtualizingStackPanel/>
                    </ItemsPanelTemplate>
                </ComboBox.ItemsPanel>
            </ComboBox>

        </Grid>
        <Grid x:Name="grid2" DataContext="{StaticResource estimateInformationTableViewSource1}" HorizontalAlignment="Left" VerticalAlignment="Top" Width="311">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="Auto"/>
                <ColumnDefinition Width="Auto"/>
            </Grid.ColumnDefinitions>
            <Grid.RowDefinitions>
                <RowDefinition Height="Auto"/>
            </Grid.RowDefinitions>
            <Label Content="DESCRIPTION:" Grid.Column="0" HorizontalAlignment="Left" Margin="3" Grid.Row="0" VerticalAlignment="Center"/>
            <ComboBox x:Name="dESCRIPTIONComboBox" Grid.Column="1" DisplayMemberPath="DESCRIPTION" HorizontalAlignment="Left" Height="Auto" ItemsSource="{Binding}" Margin="3,9,-53,9" Grid.Row="0" VerticalAlignment="Center" Width="180">
                <ComboBox.ItemsPanel>
                    <ItemsPanelTemplate>
                        <VirtualizingStackPanel/>
                    </ItemsPanelTemplate>
                </ComboBox.ItemsPanel>
            </ComboBox>
        </Grid>
    </StackPanel>


</Page>

当前代码隐藏

namespace gobo.Pages
{
    /// <summary>
    /// Interaction logic for TESTSTUFF01.xaml
    /// </summary>
    public partial class TESTSTUFF01 : Page
    {
        private gobo.gobo2018DataSet1 gobo2018DataSet1;
        public gobo.gobo2018DataSet1TableAdapters.EstimateInformationTableTableAdapter gobo2018DataSet1TableAdapter;
        private CollectionViewSource estimateInformationTableViewSource;

        private gobo.gobo2018EstimateInformationTableDescriptionDataSet gobo2018EstimateInformationTableDescriptionDataSet;
        private gobo.gobo2018EstimateInformationTableDescriptionDataSetTableAdapters.EstimateInformationTableTableAdapter EstimateInformationTableTableAdapter;
        private CollectionViewSource estimateInformationTableViewSource1;


        public TESTSTUFF01()
        {
            InitializeComponent();
        }

        private void Page_Loaded(object sender, RoutedEventArgs e)
        {

            gobo2018DataSet1 = ((gobo.gobo2018DataSet1)(this.FindResource("gobo2018DataSet1")));
            gobo2018DataSet1TableAdapter = new gobo.gobo2018DataSet1TableAdapters.EstimateInformationTableTableAdapter();
            gobo2018DataSet1TableAdapter.Fill(gobo2018DataSet1.EstimateInformationTable);
            estimateInformationTableViewSource = ((System.Windows.Data.CollectionViewSource)(this.FindResource("estimateInformationTableViewSource")));
            estimateInformationTableViewSource.View.MoveCurrentToFirst();

            gobo2018EstimateInformationTableDescriptionDataSet = ((gobo.gobo2018EstimateInformationTableDescriptionDataSet)(this.FindResource("gobo2018EstimateInformationTableDescriptionDataSet")));
            EstimateInformationTableTableAdapter = new gobo.gobo2018EstimateInformationTableDescriptionDataSetTableAdapters.EstimateInformationTableTableAdapter();
            EstimateInformationTableTableAdapter.FillByCategory(gobo2018EstimateInformationTableDescriptionDataSet.EstimateInformationTable,"ACC");
            estimateInformationTableViewSource1 = ((System.Windows.Data.CollectionViewSource)(this.FindResource("estimateInformationTableViewSource1")));
            estimateInformationTableViewSource1.View.MoveCurrentToFirst();


        }

        public void LoadDescriptionToCbo(String parameter)
        {
            if(gobo2018EstimateInformationTableDescriptionDataSet != null)
            {
                EstimateInformationTableTableAdapter.FillByCategory(gobo2018EstimateInformationTableDescriptionDataSet.EstimateInformationTable, parameter);
            }

        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            LoadDescriptionToCbo("ACT");
            Console.WriteLine("Button Click -> LoadDescriptionToCode");
        }
    }
}
4

1 回答 1

0

我发现这行得通，但我很好奇这是否是最好的答案。

private void cATEGORYComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            ComboBox cbx = (ComboBox)sender;
            string s = ((DataRowView)cbx.Items.GetItemAt(cbx.SelectedIndex)).Row.ItemArray[0].ToString();    
            LoadDescriptionToCbo(s);

        }
于 2017-11-24T21:03:30.360 回答