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I'm working all day on this, but I'm stuck and don't have a solution. It seems pretty simple..

I have a datagrid with a dynamic amount of columns. Each column has a DataGridTemplateColumn with a CellTemplate and a CellEditingTemplate. The CellEditingTemplate contains a Combobox with values which after the user has selected a value, the TextBox in the CellTemplate has to be updated to the selected value. Normally you would bind this to a known property in an object, but since I don't know how many columns the user needs in advance, I have to create these properties (or something else) at runtime and try to bind this textbox and combobox to this property. How do I solve this? I prefer to not use ExpandoObjects and I'm bounded to .net 4.0

My solution (which didn't work yet) is to add a wrapperobject to a list/array in each row object and then generate a new DataGridTemplateColumn in code where the combobox and the textbox have databindings to this wrapperobject in the array. In XAML this would look something like , but I can't get this 0 changed into 1,2,3,... I could do this in the code behind, but I don't know how to bind it to a WrapperObjectList[X].Value?

Here is a simplified example, hopefully helping understanding what I'd like to achieve:

I have datagrid which is binded to an observablecollection with RowObjects [rowobject represents 1 row.. ;) ]. The first column is fixed, so it's binded to a property in a RowObject.

Now I have to add a dynamic amount of columns after this. This is based on how many items the user has selected (not in the example, but you'll get the point). I replaced this action with clicking the button.

For each column I create a wrapperobject and add this to another observablecollection within the RowObject. This gives me a bit of flexibility since I don't know in advance how many columns will be added. This Wrapperobject contains the value I need to display.

Furthermore, I need this WrapperObject to be binded to a selection in my combobox. So if I edit a row, I select a value from the combobox and then this selected value has to be displayed (set) in the TextBox of the celltemplate.

Example code:

Code behind:

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        LoadData();


        this.DataContext = RowList;

    }

    private void LoadData()
    {
        RowList = new ObservableCollection<RowObject>();
        WrapperObject lWrapperObject1 = new WrapperObject();
        lWrapperObject1.Value = 1;
        WrapperObject lWrapperObject2 = new WrapperObject();
        lWrapperObject2.Value = 2;

        WrapperObject lWrapperObject3 = new WrapperObject();
        lWrapperObject3.Value = 3;
        WrapperObject lWrapperObject4 = new WrapperObject();
        lWrapperObject4.Value = 4;

        WrapperObject lWrapperObject6 = new WrapperObject();
        lWrapperObject6.Value = 6;
        WrapperObject lWrapperObject8 = new WrapperObject();
        lWrapperObject6.Value = 8;

        RowObject lRowObject1 = new RowObject();
        lRowObject1.RowObjectName = "RowObject1";
        lRowObject1.WrapperCollection.Add(lWrapperObject1);
        lRowObject1.WrapperCollection.Add(lWrapperObject2);
        lRowObject1.WrapperCollection.Add(lWrapperObject6);

        RowObject lRowObject2 = new RowObject();
        lRowObject2.RowObjectName = "RowObject2";
        lRowObject2.WrapperCollection.Add(lWrapperObject3);
        lRowObject2.WrapperCollection.Add(lWrapperObject4);
        lRowObject2.WrapperCollection.Add(lWrapperObject8);

        RowList.Add(lRowObject1);
        RowList.Add(lRowObject2);


    }

    public ObservableCollection<RowObject> RowList { get; set; }


    private void Button_Click(object sender, RoutedEventArgs e)
    {
        DataGridTemplateColumn lTemplateColumn = new DataGridTemplateColumn();
        lTemplateColumn.Header = "NewDynamicColumn";
        var lMyCellTemplate= (DataTemplate)Resources["myCellTemplate"];
        var lMyCellEditingTemplate = (DataTemplate)Resources["myCellEditingTemplate"];

        // Text="{Binding WrapperCollection[1].Value}" ????

        lTemplateColumn.CellTemplate =lMyCellTemplate;
        lTemplateColumn.CellEditingTemplate = lMyCellEditingTemplate;
        this.MyGrid.Columns.Add(lTemplateColumn);
    }
}

public class RowObject : INotifyPropertyChanged
{

    public RowObject()
    {
        WrapperCollection = new ObservableCollection<WrapperObject>();
        ComboBoxList = new List<string>();
        ComboBoxList.Add("10");
        ComboBoxList.Add("20"); 
    }

    public ObservableCollection<WrapperObject> WrapperCollection { get; set; }

    private string fRowObjectName;

    public string RowObjectName
    {
        get { return fRowObjectName; }
        set
        {
            fRowObjectName = value;
            RaisePropertyChanged("RowObjectName");
        }
    }

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

    #region Notify property changed
    public event PropertyChangedEventHandler PropertyChanged;
    public void RaisePropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
    #endregion

}

public class WrapperObject : INotifyPropertyChanged
{
    private int fValue;

    public int Value 
    { 
        get {return fValue;}
        set
        {
            fValue = value;
            RaisePropertyChanged("Value");
        }
    }

    #region Notify property changed
    public event PropertyChangedEventHandler PropertyChanged;
    public void RaisePropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
    #endregion
}

Xaml:

<Window.Resources>
    <DataTemplate x:Key="myCellTemplate">
        <TextBlock Text="{Binding WrapperCollection[1].Value}" />
    </DataTemplate>

    <DataTemplate x:Key="myCellEditingTemplate">
        <ComboBox ItemsSource="{Binding ComboBoxList}" />
    </DataTemplate>
</Window.Resources>

<StackPanel>
    <DataGrid   x:Name="MyGrid" 
                AutoGenerateColumns="False"
                ItemsSource="{Binding}"
                >
        <DataGrid.Columns>
            <DataGridTextColumn Header="Name" Binding="{Binding RowObjectName}"/>
            <DataGridTextColumn Header="ExampleColumn1" Binding="{Binding WrapperCollection[0].Value}"/>
            <DataGridTemplateColumn Header="ExampleColumn2" CellTemplate="{StaticResource myCellTemplate}" CellEditingTemplate="{StaticResource myCellEditingTemplate}"/>           
        </DataGrid.Columns>
    </DataGrid>
    <Button Content="Click" Click="Button_Click" Width="100" Margin="20"/>
</StackPanel>

ExampleColumn1 and ExampleColumn2 are the only editable columns in this example and once you click the button, the added column(s) are also editable. Right now I think the solution is something like creating a new binding to the WrapperCollection[2].Value, WrapperCollection[3].Value etc. in the code behind, but how?

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1 回答 1

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XAMLReader 救了我！现在我可以创建任何我想要的 DataTemplate..

    public DataTemplate CreateDataTemplate(Type type, int aNumber)
    {
        StringReader stringReader = new StringReader(
        @"<DataTemplate xmlns=""http://schemas.microsoft.com/winfx/2006/xaml/presentation""> 
        <" + type.Name + @" Text=""{Binding WrapperCollection[" + aNumber.ToString() + @"].Value}""/> 
    </DataTemplate>");
        XmlReader xmlReader = XmlReader.Create(stringReader);
        return XamlReader.Load(xmlReader) as DataTemplate;
    }

{
    ...
    TextBlock textBlock = new TextBlock();
    var lMyCellTemplate = CreateDataTemplate(textBlock.GetType(), Counter);
}
于 2013-09-05T15:45:16.137 回答