使用绑定禁用特定DataGrid单元格

Question

我正在尝试将自定义数据对象列表绑定到数据网格,并实现以下行为.

1. 填充网格
2. 根据对象数据禁用某些单元格.

考虑以下DataGrid

<DataGrid ItemsSource="{Binding Path=CustomObjectList}">
    <DataGrid.Columns>
        <DataGridTextColumn Binding="{Binding Path=FieldName}"
                            Header="Field Name"
                            IsReadOnly="True" />
        <DataGridCheckBoxColumn Binding="{Binding Path=Compare}"
                                Header="Compare" />
        <DataGridTextColumn Binding="{Binding Path=Tolerance}"
                            Header="Tolerance" />
    </DataGrid.Columns>
</DataGrid>

有这样的支持对象......

public class CustomObject: BaseModel
{
    private bool _compare;

    private bool _disableTolerance;

    private string _fieldName;

    private bool _mustCompare;

    private double _tolerance;

    /// <summary>
    /// Gets or sets the compare.
    /// </summary>
    /// <value>The compare.</value>
    public bool Compare
    {
        get
        {
            return this._compare;
        }
        set
        {
            this._compare = value;
            this.NotifyPropertyChange("Compare");
        }
    }

    /// <summary>
    /// Gets or sets the disable tolerance.
    /// </summary>
    /// <value>The disable tolerance.</value>
    public bool DisableTolerance
    {
        get
        {
            return this._disableTolerance;
        }
        set
        {
            this._disableTolerance = value;
            this.NotifyPropertyChange("DisableTolerance");
        }
    }

    /// <summary>
    /// Gets or sets the name of the field.
    /// </summary>
    /// <value>The name of the field.</value>
    public string FieldName
    {
        get
        {
            return this._fieldName;
        }
        set
        {
            this._fieldName = value;
            this.NotifyPropertyChange("FieldName");
        }
    }

    /// <summary>
    /// Gets or sets the must compare.
    /// </summary>
    /// <value>The must compare.</value>
    public bool MustCompare
    {
        get
        {
            return this._mustCompare;
        }
        set
        {
            this._mustCompare = value;
            this.NotifyPropertyChange("MustCompare");
        }
    }

    /// <summary>
    /// Gets or sets the tolerance.
    /// </summary>
    /// <value>The tolerance.</value>
    public double Tolerance
    {
        get
        {
            return this._tolerance;
        }
        set
        {
            this._tolerance = value;
            this.NotifyPropertyChange("Tolerance");
        }
    }
}

你可以考虑像这样填充CustomObjectList ......

this.ComparisonsAndTolerances.Add(new ComparisonSettingsTolerances()
{
    FieldName = "Alpha",
    Compare = true,
    MustCompare = true,
    Tolerance = 0,
    DisableTolerance = false
});

this.ComparisonsAndTolerances.Add(new ComparisonSettingsTolerances()
{
    FieldName = "Bravo",
    Compare = true,
    MustCompare = false,
    Tolerance = 0,
    DisableTolerance = true
});

因此,FieldName,Compare和Tolerance属性当然适当地填充到网格中.

但是,我想要实现的是,当MustCompare为真时,该单元格被标记为只读.当DisableTolerance为true时,该单元格被标记为只读.

显然,这将因细胞与细胞和行与行有4种不同的组合而有所不同,但我希望通过绑定实现这一目标.

我试过了

IsReadOnly="{Binding Path=MustCompare}"

和

IsReadOnly="{Binding Path=CustomObjectList/MustCompare}"

但这些都没有奏效.

谢谢.

Answer 1

这是你遇到的一个有趣的错误/情况.

怎么了？好吧,绑定试图绑定到MustCompare属性(并且可能会成功)但它无法找到FrameworkElement或FrameworkContentElement成为绑定的目标,因为数据网格的列都不在可视树中.

有一个解决方案,虽然没有你(正当地)尝试做的那么优雅:

<DataGridTemplateColumn Header="Compare">
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <TextBlock x:Name="TextHolder" />
            <DataTemplate.Triggers>
                <DataTrigger Binding="{Binding Path=Compare}"
                             Value="True">
                    <Setter TargetName="TextHolder"
                            Property="Text"
                            Value="True" />
                </DataTrigger>
                <DataTrigger Binding="{Binding Path=Compare}"
                             Value="False">
                    <Setter TargetName="TextHolder"
                            Property="Text"
                            Value="False" />
                </DataTrigger>
            </DataTemplate.Triggers>
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
    <DataGridTemplateColumn.CellEditingTemplate>
        <DataTemplate>
            <CheckBox x:Name="Check"
                      IsChecked="{Binding Path=Compare}"
                      ToolTipService.ShowOnDisabled="True"/>
            <DataTemplate.Triggers>
                <DataTrigger Binding="{Binding Path=MustCompare}"
                             Value="True">
                    <Setter TargetName="Check"
                            Property="IsEnabled"
                            Value="False" />
                    <Setter TargetName="Check"
                            Property="ToolTip"
                            Value="You cannot change this value since this item must compare" />
                </DataTrigger>
            </DataTemplate.Triggers>
        </DataTemplate>
    </DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>

我已经更改了单元格,因此它在非编辑模式下显示文本,在编辑时显示复选框(只是为了查看单元格的状态,在两种情况下都可以将其更改为复选框).

这不是最佳选择,如果您(或任何人)找到更好的解决方案,我想听听您的意见.

编辑:

想到另一个解决方案:

<DataGridCheckBoxColumn Binding="{Binding Path=Compare}"
                        Header="Compare">
    <DataGridCheckBoxColumn.CellStyle>
        <Style TargetType="{x:Type DataGridCell}">
            <Style.Triggers>
                <DataTrigger Binding="{Binding MustCompare}"
                             Value="True">
                    <Setter Property="IsEnabled"
                            Value="False" />
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </DataGridCheckBoxColumn.CellStyle>
</DataGridCheckBoxColumn>

这使得复选框在非编辑模式下被禁用,因此它看起来不同.取决于您的功能设计,可能是好事还是坏事.