WPF DataGrid自定义模板自动生成的列内容绑定

Question

so I've got a datagrid whose SourceItem structure is unknown, but needs a tiny tweak... i'm using AutoGenerateColumns but for one of the data types I override with my own column using the dg_AutoGeneratingColumn event wherein I check the e.PropertyType and override the e.Column with my new ColumnTemplate (inherits from DataGridBoundColumn).

Generally speaking it executes and renders fine, except that i'm trying to get the data binding (path is unknown) to flow into my custom ColumnTemplate.

CustomTemplate : DataGridBoundColumn
{
    public static DependencyProperty dpblah;
    private void MyCode() { GetValue(dpBlah); }
}

DataGrid_AutoGeneratingColumn(...) {
    var oldBinding = (e.Column as DataGridBoundColumn).Binding;
    e.Column = new CustomTemplate { Header = e.PropertyName };
    BindingOperations.SetBinding(e.Column, dpBlah, oldBinding);
}

everything seems to run, but when MyCode() runs, GetValue has nothing.

Is there something I'm missing? Why can't I get the value from the binding?

Answer 1

You can set your property to the path of the binding and then use this path when you create the visual elements in your CustomTemplate class:

var oldBinding = (e.Column as DataGridBoundColumn).Binding as Binding;
e.Column = new CustomTemplate { Header = e.PropertyName, dpblah = oldBinding?.Path?.Path; };

In CustomTemplate , you could then get the value of the property for a specific item using reflection, eg:

protected override FrameworkElement GenerateElement(DataGridCell cell, object dataItem)
{
    string bindingPath = dpblah;
    object value = dataItem.GetType().GetProperty(bindingPath).GetValue(dataItem);
    ...
}

If dataItem is a DataRowView you don't have to use reflection:

DataRowView drv = dataItem as DataRowView;
if(drv != null)
{
    object value = drv[bindingPath];
}