Avalonia DataGrid无法显示全部行问题求助

针对你遇到的DataGrid无法完整显示200条数据、滚动条失效的问题，以下是几个可行的排查和解决方向：

1. 确保ViewModel实现INotifyPropertyChanged #

你的代码中直接给Records赋值新的ObservableCollection，但如果ViewModel没有实现INotifyPropertyChanged接口，UI可能无法感知到数据源的更新，导致显示异常。修改ViewModel：

public class YourViewModel : INotifyPropertyChanged
{
    private ObservableCollection<Record> _records;
    public ObservableCollection<Record> Records
    {
        get => _records;
        set
        {
            _records = value;
            OnPropertyChanged();
        }
    }

    private int _count;
    public int Count
    {
        get => _count;
        set
        {
            _count = value;
            OnPropertyChanged();
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    public void OnClickCommand()
    {
        Records = new ObservableCollection<Record>(r.GetData(Path).ToList());
        Count = Records.Count;
    }
}

2. 调整DataGrid的虚拟化设置 #

Avalonia DataGrid默认启用UI虚拟化，若虚拟化容器的高度计算出现问题，会导致部分数据无法渲染。可以尝试关闭虚拟化：

<DataGrid Name="DataGridResults" 
          Items="{Binding Records}" 
          AutoGenerateColumns="False"
          VirtualizingStackPanel.IsVirtualizing="False">
    <DataGrid.Columns>
        <DataGridTextColumn Header="ID" Binding="{Binding ID}"/>
        <DataGridTextColumn Header="Path" Binding="{Binding File}"/>
        <DataGridTextColumn Header="Name" Binding="{Binding Name}"/>
    </DataGrid.Columns>
</DataGrid>

如果需要保留虚拟化，可尝试设置虚拟化模式为Recycling：

<DataGrid Name="DataGridResults" 
          Items="{Binding Records}" 
          AutoGenerateColumns="False"
          VirtualizingStackPanel.VirtualizationMode="Recycling">
    <!-- 列定义 -->
</DataGrid>

3. 检查父容器布局 #

如果DataGrid的父容器是StackPanel，它会根据内容自动调整高度，但可能导致DataGrid的可视区域计算错误。建议将父容器替换为Grid或DockPanel，确保DataGrid有明确的高度约束：

<Grid>
    <DataGrid Name="DataGridResults" 
              Items="{Binding Records}" 
              AutoGenerateColumns="False">
        <!-- 列定义 -->
    </DataGrid>
</Grid>

避免将DataGrid嵌套在ScrollViewer中，否则会和DataGrid自身的滚动逻辑冲突。

4. 强制刷新DataGrid布局 #

在赋值数据源后，手动触发DataGrid的布局刷新：

public void OnClickCommand()
{
    Records = new ObservableCollection<Record>(r.GetData(Path).ToList());
    Count = Records.Count;
    // 确保控件已加载后调用
    DataGridResults?.InvalidateMeasure();
    DataGridResults?.InvalidateArrange();
}

如果是MVVM模式无法直接访问控件，可通过Dispatcher异步调用：

Application.Current.Dispatcher.Post(() =>
{
    DataGridResults?.InvalidateMeasure();
    DataGridResults?.InvalidateArrange();
});

5. 排查Record类的属性绑定 #

确保Record类的属性是公开可访问的，若需要动态更新属性值，也需实现INotifyPropertyChanged接口：

public class Record : INotifyPropertyChanged
{
    private int _id;
    public int ID
    {
        get => _id;
        set
        {
            _id = value;
            OnPropertyChanged();
        }
    }

    private string _file;
    public string File
    {
        get => _file;
        set
        {
            _file = value;
            OnPropertyChanged();
        }
    }

    private string _name;
    public string Name
    {
        get => _name;
        set
        {
            _name = value;
            OnPropertyChanged();
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

内容的提问来源于stack exchange，提问作者user20510170