如何使用StaticResource在XAML中定义DataContext

Question

我想通过XAML中的静态资源声明一个DataContext,作为Northwind数据库中Customers的绑定.我可以在代码(C#)中轻松完成此操作,但想学习如何在XAML中完成.我已经尝试了所有可以找到的例子,但它们都不适合我.我认为这个问题出现在我标记为[Option1]和[Option2]的两行XAML代码行中.你能澄清一下这个语法应该是什么吗？

C#

namespace DataGridEF
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            bModel1 bNorthWind = new bModel1();
            //this.DataContext = bNorthWind;
            bNorthWind.GetCustomers();
        }
    }
}

namespace DataGridEF
{
    public class bModel1
    {
        List<Customer> _Customers;
        public List<Customer> Customers
        {
            get { return _Customers; }
            set { _Customers = value; }
        }

        public void GetCustomers()
        {
            NorthwindEntities NorthWind = new NorthwindEntities();
            var CustomerQ = from cust in NorthWind.Customers select cust;
            _Customers = CustomerQ.ToList();
        }

    }
}

XAML

 <Window x:Class="DataGridEF.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525"
    xmlns:vm="clr-namespace:DataGridEF">

<Window.Resources>
    <vm:bModel1 x:Key="TheViewModel" />
</Window.Resources>

<Grid>
    <DataGrid AutoGenerateColumns="False" Height="195" 
              HorizontalAlignment="Left" Margin="20,89,0,0" 
              Name="dataGrid1" ItemsSource="{Binding Path=Customers}" 
              [option1]DataContext="{StaticResource TheViewModel}"
              [option2]DataContext=
                  "{Binding Path=., Source={StaticResource TheViewModel}}"
              VerticalAlignment="Top" Width="471" >
        <DataGrid.Columns>
            <DataGridTextColumn Header="Name" Binding="{Binding Path=ContactName}" />
            <DataGridTextColumn Header="Address" Binding="{Binding Path=Address}" />
            <DataGridTextColumn Header="City" Binding="{Binding Path=City}" />
        </DataGrid.Columns>
    </DataGrid>
</Grid>
</Window>

Answer 1

如果为了避免使实体框架和MSSQL NorthWind数据库的问题复杂化,那么在Exampleproject" WPF/MVVM快速入门教程 "的 示例2示例代码中提供了很好的说明.

对于您的XAML,您应该将其开头更改为:

<Window x:Class="DataGridEF.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525"
    xmlns:vm="clr-namespace:DataGridEF">

<Window.DataContext>
        <vm:bNorthWind />
    </Window.DataContext>
<Grid>
<!---Couldnt check your code due to dependencies on 
     EF and MSSQL NorthWind database

     See the reference for working illustration sample:
 http://www.codeproject.com/Articles/165368/WPF-MVVM-Quick-Start-Tutorial

-->
</Grid>
</Window>

这种方法的另一种变体可以在"在代码中设置DataContext而不是XAML的优势是什么？"中可以看到., 那个部分:

    <StackPanel.DataContext>
        <local:CustomerViewModel />
    </StackPanel.DataContext>   

迁移DataContext从代码隐藏到XAML定义是无关的任一使用StaticResource或DynamicResource.请参阅: WPF中StaticResource和DynamicResource之间的区别是什么？可能在codeproject WPF中更好地解决:StaticResource与DynamicResource

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• 为什么在XAML中绑定MainWindow datacontext失败的行为与使用this.datacontext = this的代码隐藏中的绑定相同？