Question

我有一个Datagrid，应该是我运行的SSH命令的列表。由于某种原因，它没有追加到列表中，只是替换了内容。这是XAML：

<DataGrid Name="CommandRows2" Margin="0,0,0,87" AutoGenerateColumns="False">
    <DataGrid.Columns>
        <DataGridCheckBoxColumn Header="Delete" Binding="{Binding Delete}"/>
        <DataGridTextColumn Header="Command" Binding="{Binding Command}" Width="200"/>
        <DataGridTextColumn Header="Response" Binding="{Binding Response}" Width="*"/>
        <DataGridTextColumn Header="Test Results" Binding="{Binding Results}" Width="70"/>
    </DataGrid.Columns>
</DataGrid>

代码如下：

List<CommandGridItems> items = new List<CommandGridItems>();

private void ExecuteSingleCommand(object sender, RoutedEventArgs e)
{
    string sshCommand = "hostname";
    string returnedResults = "localhost";
    items.Add(new CommandGridItems() { Delete = false, Command = sshCommand, Response = returnedResults, Results = "desc1" });
    CommandRows2.ItemsSource = items;
}

public class CommandGridItems
{
    public bool Delete { get; set; }
    public string Command { get; set; }
    public string Response { get; set; }
    public string Results { get; set; }
}

Answer 1

当您反复设置CommandRows2.ItemsSource = items;时，第二和下一个分配都不会发生任何事情，因为值（items）不变，它是相同的引用。

将List<CommandGridItems> items = new List<CommandGridItems>();更改为ObservableCollection<CommandGridItems> items = new ObservableCollection<CommandGridItems>();，只需添加新元素，而无需重新分配ItemsSource：

private void ExecuteSingleCommand(object sender, RoutedEventArgs e)
{
    string sshCommand = "hostname";
    string returnedResults = "localhost";
    var element = new CommandGridItems() { Delete = false, Command = sshCommand, Response = returnedResults, Results = "desc1" }
    items.Add(element);
}

一个单独添加的元素将显示在DataGrid中，因为ObservableCollection通过INotifyCollectionChanged接口事件（CollectionChanged）通知元素更改，而在这种情况下调用Refresh会对性能造成影响。 / p>

INotifyCollectionChanged和INotifyPropertyChanged在WPF中是“必须做的”，用于通知UI有关ViewModel中的更改

Answer 2

刷新Dim Range1 As Range Set Range1 = .Range("J2:J" & LRow) Range1.Value = Range1.Value列表即可。

Items

在ButtonClick上将行追加到DataGrid

2 个答案: