我的DataGrid的{{1}}返回空对象或null。可能是这样的？所有属性都绑定。在添加数据时，它在网格上显示正确，但在检索它时会给出null。
ItemSource后端对象：
<DataGrid AutoGenerateColumns="False" Grid.Row="2" Height="208" HorizontalAlignment="Left" Margin="20,71,0,0" Name="dgvWell" VerticalAlignment="Top" Width="528" HorizontalScrollBarVisibility="Visible"
VerticalScrollBarVisibility="Visible" BorderBrush="#FFB7B39D" Background="LightYellow" RowBackground="LightGray" AlternatingRowBackground="#FFFFFFF5" BorderThickness="10" CanUserReorderColumns="False" CanUserSortColumns="False" FontSize="13" CanUserAddRows="False">
<DataGrid.Columns>
<DataGridTextColumn Header="Layer Name" Width="80" Binding="{Binding LayerName}"/>
<DataGridTextColumn Width="100" Binding="{Binding Porosity}">
<DataGridTextColumn.Header>
<Grid Width="100">
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition/>
</Grid.RowDefinitions>
<TextBlock Text="Porosity" Grid.Row="0"/>
<ComboBox Grid.Row="1" Width="70" HorizontalAlignment="Center" Name="cboPorosity">
<ComboBoxItem Content="pascal" IsSelected="True" />
<ComboBoxItem Content="psi"/>
<ComboBoxItem Content="bar"/>
<ComboBoxItem Content="barye"/>
</ComboBox>
</Grid>
</DataGridTextColumn.Header>
</DataGridTextColumn>
<DataGridTextColumn Header="Permeability" Binding="{Binding Permeability}"/>
<DataGridTextColumn Width="120" Binding="{Binding Path= PerforationStartDepth,Mode=TwoWay}" ClipboardContentBinding="{Binding PerforationStartDepth}">
<DataGridTextColumn.Header>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="25"/>
<RowDefinition/>
</Grid.RowDefinitions>
<TextBlock Text="Perforation Start" Grid.Row="0"/>
<ComboBox Grid.Row="1" Width="60" Name="cboPerfStart">
<ComboBoxItem Content="ft" IsSelected="True" />
<ComboBoxItem Content="M"/>
<ComboBoxItem Content="cm"/>
</ComboBox>
</Grid>
</DataGridTextColumn.Header>
</DataGridTextColumn>
<DataGridTextColumn Width="145" Binding="{Binding PerforationEndDepth}">
<DataGridTextColumn.Header>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="25"/>
<RowDefinition/>
</Grid.RowDefinitions>
<TextBlock Text="Perforation End" Grid.Row="0"/>
<ComboBox Grid.Row="1" Width="60" Name="cboPerfEnd">
<ComboBoxItem Content="ft" IsSelected="True"/>
<ComboBoxItem Content="M"/>
<ComboBoxItem Content="cm"/>
</ComboBox>
</Grid>
</DataGridTextColumn.Header>
</DataGridTextColumn>
<DataGridTextColumn Width="140" Binding="{Binding ReservoirPressure,Mode=TwoWay}">
<DataGridTextColumn.Header>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="25"/>
<RowDefinition/>
</Grid.RowDefinitions>
<TextBlock Text="Reservoir Pressure" Grid.Row="0"/>
<ComboBox Grid.Row="1" Width="60" Name="cboResPress">
<ComboBoxItem Content="pascal" IsSelected="True" />
<ComboBoxItem Content="psi"/>
<ComboBoxItem Content="bar"/>
<ComboBoxItem Content="barye"/>
</ComboBox>
</Grid>
</DataGridTextColumn.Header>
</DataGridTextColumn>
<DataGridTextColumn Width="145" Header="Water Cut" Binding="{Binding WaterCut}"></DataGridTextColumn>
</DataGrid.Columns>
</DataGrid>
上述检索返回null。
你能帮我知道吗，为什么这个网格没有返回正确的ItemSource。
修改
基于你的帮助，我帮助了很多，我实现了我的代码。在我看来，我有一个组合框允许用户选择一个数字。根据该数字，可以将许多行添加到网格中。我尝试了它，但它没有显示任何行：
在我的Model类中：
public struct Step2Data
{
public string LayerName { get; set; }
public int Porosity { get; set; }
public int Permeability { get; set; }
public int PerforationStartDepth { get; set; }
public int PerforationEndDepth { get; set; }
public int ReservoirPressure { get; set; }
public int WaterCut { get; set; }
}
List<Step2Data> step2datas = dgvWell.ItemsSource as List<Step2Data>;
DataGrid绑定到Step2ModelList
public ObservableCollection<Step2Model> Step2ModelList
{
get {
if (step2ModelList == null)
step2ModelList = new ObservableCollection<Step2Model>();
return step2ModelList;
}
set
{
step2ModelList = value;
Changed("Step2ModelList");
}
}
public void AddStep2ModelToList(Step2Model step2Model)
{
Step2ModelList.Add(step2Model);
}
public void addRowsToList(int count)
{
for (int i = 0; i < count; i++)
{
Step2ModelList.Add(new Step2Model()); // UPDATED
/*
AddItemCommand = new ActionCommand
{
ExecuteDelegate = o => Step2ModelList.Add(new Step2Model())
};
*/
}
}
在组合框选择中，
ItemsSource="{Binding Step2ModelList, Mode=TwoWay}">
此后，网格不会反映Step2ModelList中添加的2行。
答案 0 :(得分：1)
我认为，您不了解DataGrid.ItemSource的概念。阅读http://msdn.microsoft.com/en-us/library/system.windows.controls.datagrid.itemssource(v=vs.95).aspx
DataGrid.ItemSource用于填充DataGrid而不是相反。
如果要访问DataGrid项目，请使用：
dgvWell.Items;
更新，ObservableCollection示例：
视图模型：
public class DataGridSampleViewModel
{
public ObservableCollection<Step2Data> Data { get; set; }
public ICommand AddItemCommand { get; set; }
public DataGridSampleViewModel()
{
Data = new ObservableCollection<Step2Data>();
AddItemCommand = new ActionCommand
{
ExecuteDelegate = o => Data.Add(new Step2Data { LayerName = DateTime.Now.Ticks.ToString() })
};
}
}
查看背后的代码：
public partial class DataGridSampleView : Window
{
public DataGridSampleView()
{
InitializeComponent();
this.DataContext = new DataGridSampleViewModel();
}
}
查看：
<Window x:Class="SimpleMVVMApp.DataGridSampleView"
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:simpleMvvmApp="clr-namespace:SimpleMVVMApp"
mc:Ignorable="d"
Title="DataGridSampleView" Height="300" Width="300"
d:DataContext="{d:DesignInstance simpleMvvmApp:DataGridSampleViewModel}">
<StackPanel>
<Button Content="Add new item" Command="{Binding AddItemCommand}" />
<ListBox ItemsSource="{Binding Data}">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Text="{Binding LayerName}" />
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>
</Window>