Question

正如标题所述，我尝试从2个不同的ViewModel中获取数据，但是上面没有显示任何内容。我做错了吗？
这是我的XAML

<Window.DataContext>
    <local:VMContainer/>
</Window.DataContext>
<Grid>
    <StackPanel Orientation="Horizontal">
        <ItemsControl ItemsSource="{Binding Path=VM1.LibraryVM1}">
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <Image Width="150" Height="200" Source="{Binding Path=cover}" />
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>
        <ItemsControl ItemsSource="{Binding Path=VM2.LibraryVM2}">
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <Image Width="150" Height="200" Source="{Binding Path=cover}" />
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>
    </StackPanel>
</Grid>

我的容器

public class VMContainer
{
    public VModel1 VM1 { get; set; }
    public VModel2 VM2 { get; set; }
}

ViewModel 1

public class VModel1
{
    public DataView LibraryVM1 { get; private set; }
    public VModel1()
    {
        DataTable vm1 = new DataTable();
        using (MySqlConnection connection = new MySqlConnection("SERVER=localhost;" + "DATABASE=library;" + "UID=root;" + "PASSWORD=;"))
        {
            MySqlDataAdapter adapter = new MySqlDataAdapter();
            adapter.SelectCommand = new MySqlCommand("Select * from index_movie_list", connection);
            adapter.Fill(vm1);
        }
        LibraryVM1 = vm1.DefaultView;
    }
}

ViewModel 2

public class VModel2
{
    public DataView LibraryVM2 { get; private set; }
    public VModel2()
    {
        DataTable vm2 = new DataTable();
        using (MySqlConnection connection = new MySqlConnection("SERVER=localhost;" + "DATABASE=library;" + "UID=root;" + "PASSWORD=;"))
        {
            MySqlDataAdapter adapter = new MySqlDataAdapter();
            adapter.SelectCommand = new MySqlCommand("Select * from index_tv_list", connection);
            adapter.Fill(vm2);
        }
        LibraryVM2 = vm2.DefaultView;
    }
}

当我运行程序时，它仅显示空白白色。当我在没有容器的情况下更改它并选择1 ViewModel时，仅显示图像，但无法查看ViewModel2。有解决方案吗？

编辑：由于Loocid的回答，我初始化了VM1和VM2之后解决了问题。

Answer 1

您的VMContainer不会初始化VModel1和VModel2，因此您将绑定到null。

尝试一下：

public class VMContainer
{
    public VModel1 VM1 { get; set; } = new VModel1();
    public VModel2 VM2 { get; set; } = new VModel2();
}

如何从2 ViewModel WPF绑定数据

1 个答案: