动态调整列大小以适应 WPF 中的 DataGrid

Question

我有代码在 Grid 列中动态添加自定义 DataGrid 对象，例如：

DataGrid dg = new DataGrid();
var vm = new MyViewModel();
dg.DataContext = vm;
dg.ItemsSource = vm.Items;

dg.VerticalAlignment = VerticalAlignment.Stretch;
dg.HorizontalAlignment = HorizontalAlignment.Stretch;

dg.AutoGenerateColumns = false;
dg.CanUserAddRows = false;
dg.CanUserResizeColumns = true;

dg.Columns.Clear();

dg.Columns.Add(new DataGridTextColumn
{
                Header = "Name",
                Binding = new Binding(nameof(DataItem.Path)) { Converter = new PathToNameConverter() },
                //Width = DataGridLength.Auto
});
...

// here add column definition to Grid
var gridColDefs = new ColumnDefinition();
gridColDefs.Width = GridLength.Auto;
gridColDefs.MinWidth = 500;

gridElement.ColumnDefinitions.Add(gridColDefs);
Grid.SetColumn(dg, gridElement.ColumnDefinitions.Count - 1);
gridElement.Children.Add(dg);

// populate datagrid items (I use Items => ObservableCollection<>)
await vm.FetchItemsAsync();

var star = new DataGridLength(1, DataGridLengthUnitType.Star);
dg.ColumnWidth = star;
foreach (var col in dg.Columns)
{
    col.Width = star;
}

dg.SelectionMode = DataGridSelectionMode.Extended;

在DataGrid 中填充项目后，列未填充到整个 DataGrid 宽度，如图所示保留一个空格：

我想要的是将所有列填充到它的 DataGrid 空间......我不知道我的错误在哪里

更新

Items = new ObservableCollection<DataItem>();

public override Task FetchItemsAsync(string path = null)
{
            if (string.IsNullOrWhiteSpace(path))
            {
                return Task.Run(() =>
                {
                    var mainDrive = Path.GetPathRoot(Environment.GetFolderPath(Environment.SpecialFolder.System));
                    App.Current.Dispatcher.Invoke(() => Items.Clear());

                    var folders = Directory.GetDirectories(mainDrive);
                    var files = Directory.GetFiles(mainDrive);

                    foreach (var item in folders.Union(files))
                    {
                        var isDir = FolderUtility.IsFolder(item);
                        FileSystemInfo fs = null;
                        if (isDir)
                        {
                            fs = new DirectoryInfo(item);
                        }
                        else
                        {
                            fs = new FileInfo(item);
                        }

                        App.Current.Dispatcher.Invoke(() =>
                        {
                            try
                            {
                                Items.Add(new DataItem
                                {
                                    Path = item,
                                    Size = isDir ? FolderUtility.GetFolderSize(item) : new FileInfo(item).Length,
                                    LastModifiedDate = fs.LastWriteTimeUtc,
                                    CreationDate = fs.CreationTimeUtc
                                });
                            }
                            catch { }
                            finally { }
                        });
                    }
                });
            }

            return null;
}

** 更新 2 ** 如果我使用

Width = new DataGridLength(1, DataGridLengthUnitType.Star)

对于每一列，在await 声明之后，我得到：

XAML：

<Window ...>
<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>

    <DockPanel x:Name="AppContentPanel" ScrollViewer.VerticalScrollBarVisibility="Auto" ScrollViewer.HorizontalScrollBarVisibility="Auto">
        <ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto">
            <Grid>
                <Grid.ColumnDefinitions/>
            </Grid>
        </ScrollViewer>
    </DockPanel>
</Grid>

Answer 1

如果您希望列将DataGrid 平分，可以将它们的Width 属性设置为“*”：

Width = new DataGridLength(1, DataGridLengthUnitType.Star);

编辑：

您还需要删除gridColDefs.Width = GridLength.Auto; 并将ScrollViewer 的HorizontalScrollBarVisibility 属性设置为Disabled，以便DataGrid 按预期拉伸。