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由于数据网格的列不在数据网格的可视化树中，我正在使用这种绑定代理方法来绑定DataGridTextColumn.

https://www.thomaslevesque.com/2011/03/21/wpf-how-to-bind-to-data-when-the-datacontext-is-not-inherited/

出于某种原因，我想了解相同的方法确实适用于列的属性，Visibility但不适用于列的Width属性。有人可以向我解释这种不同的行为吗？

代码示例

C＃

class BindingProxy : Freezable
{
    #region Override of Freezable
    protected override Freezable CreateInstanceCore()
    {
        return new BindingProxy();
    }
    #endregion //Override of Freezable

    public object Data
    {
        get { return (object)GetValue(DataProperty); }
        set { SetValue(DataProperty, value); }
    }

    public static readonly DependencyProperty DataProperty = DependencyProperty.Register("Data", typeof(object), typeof(BindingProxy), new UIPropertyMetadata(null));
}


public class Column : INotifyPropertyChanged
{

    public event PropertyChangedEventHandler PropertyChanged;
    protected internal void OnPropertyChanged(string propertyname)
    {
        if (PropertyChanged != null)
            PropertyChanged(this, new PropertyChangedEventArgs(propertyname));
    }

    public Column(bool visible = true)
    {
        if (visible == true)
            Visible = Visibility.Visible;
        else
            Visible = Visibility.Collapsed;

        Width = 200;
    }

    public Visibility Visible
    {
        get { return m_visible; }
        set { m_visible = value; OnPropertyChanged("Visible"); }
    }
    Visibility m_visible;

    public double Width
    {
        get { return m_width; }
        set { m_width = value; OnPropertyChanged("Width"); }
    }

    double m_width;
}

只是为了更容易复制

public partial class MainWindow : Window
{
    public MainWindow()
    {


        Lines = new ObservableCollection<tableline>();


        for (int i = 0; i< 5; i++)
            Lines.Add(new tableline());

        Columns = new List<Column>();
        Columns.Add(new Column(true));
        Columns.Add(new Column(false));

        InitializeComponent();
        DataContext = this;
    }

    public List<Column> Columns { get; set; }
    public ObservableCollection<tableline>Lines { get; set; }
}

public class tableline
{
    public tableline()
    {
        Result = new List<string>();
        int colCount = 2;
        for (int i = 0; i < colCount; i++)
        {
            Result.Add(i.ToString() + " some text");
        }

    }
    public List<string> Result { get; set; }
}

xml

<DataGrid ItemsSource="{Binding Lines}" AutoGenerateColumns="False" >
    <DataGrid.Resources>
        <local:BindingProxy x:Key="proxy" Data="{Binding}"/>
    </DataGrid.Resources>
    <DataGrid.Columns>
        <DataGridTextColumn Header="ProductId1" Binding="{Binding Path=Result[0]}" Visibility="{Binding Data.Columns[0].Visible, Source={StaticResource proxy}}" Width="{Binding Data.Columns[0].Width, Source={StaticResource proxy}}" />
        <DataGridTextColumn Header="ProductId2" Binding="{Binding Path=Result[1]}" Visibility="{Binding Data.Columns[1].Visible, Source={StaticResource proxy}}" Width="{Binding Data.Columns[1].Width, Source={StaticResource proxy}}"/>
    </DataGrid.Columns>
</DataGrid>

只是为了让你知道我最初的目标是什么。我想将所有列的宽度设置为自动，但在绘制数据网格期间使用“最大”列宽度。但是，用户应该可以调整超过此限制的大小。这就是为什么我不能使用MaxColumnWidth所以我认为实现这一点的最简单方法是读取每一列的宽度，如果它大于限制，则将其设置为“最大值”。

4

1 回答 1

1

Widtha 的属性类型DataGridColumnisDataGridLength和 not double。

更改源属性的类型：

public DataGridLength Width
{
    get { return m_width; }
    set { m_width = value; OnPropertyChanged("Width"); }
}

DataGridLength m_width;

和Mode的Binding：

<DataGridTextColumn Header="ProductId1" Binding="{Binding Path=Result[1]}"
                    Visibility="{Binding Data.Columns[0].Visible, Source={StaticResource proxy}}" 
                    Width="{Binding Data.Columns[0].Width, Source={StaticResource proxy}, Mode=TwoWay}" />
于 2017-10-17T10:02:57.353 回答