WPF MvvM DataGrid动态列 [英] WPF MvvM DataGrid Dynamic Columns

问题描述

我正在以MvvM的方式从ToolKit动态搜索如何创建DataGrid的列。但是看起来是不可能的！

I am searching about how to create the columns of the DataGrid from the ToolKit dynamic in MvvM way. But looks like it is impossible !

有没有一个人必须做这些事情？

Is there some one that had to do the samething ?

不需要创建一个来自DataGrid的用户控件或另一个控件，我只想将网格的ItemSource设置为我的自定义对象，并且在某种程度上，我想在运行时动态中定义网格的列，基于

there is no need to create a usercontrol or another control that comes from DataGrid, I just want to set de ItemSource of the grid to my custom object and in some point I want to define the columns of the grid in runtime dynamic based in the kind of the object.

可以吗？

欢呼

推荐答案

我要介绍一下，说这可能不是最好的解决方案，可能在某些情况下可能无法工作，但是可以试一下将为你想要的工作。我只是鞭打了它，所以它可能有一些错误。它仍然会涉及到一些代码，但它使您的模型不了解您的观点。

I'm going to preface this by saying it maybe isn't the best solution to be doing and may not work in some situations but you can give it a try and see if it will work for what you want. I just whipped this up so it may have some bugs in it. Its still going to involve some code, but it keeps your model from knowing about you view.

您需要做的是创建一个扩展属性，允许您绑定DataGrid上的Columns属性。这是一个我放在一起的例子。

What you need to do is create an extension property that will allow you to bind the Columns property on the DataGrid. Here is an example that I put together.

using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.Windows;
using System.Windows.Controls;

public static class DataGridExtension
{
    public static ObservableCollection<DataGridColumn> GetColumns(DependencyObject obj)
    {
        return (ObservableCollection<DataGridColumn>)obj.GetValue(ColumnsProperty);
    }

    public static void SetColumns(DependencyObject obj, ObservableCollection<DataGridColumn> value)
    {
        obj.SetValue(ColumnsProperty, value);
    }

    public static readonly DependencyProperty ColumnsProperty =  
           DependencyProperty.RegisterAttached("Columns",
           typeof(ObservableCollection<DataGridColumn>),
           typeof(DataGridExtension),
           new UIPropertyMetadata (new ObservableCollection<DataGridColumn>(),
           OnDataGridColumnsPropertyChanged));


    private static void OnDataGridColumnsPropertyChanged(
           DependencyObject d,
           DependencyPropertyChangedEventArgs e)
    {
        if (d.GetType() == typeof(DataGrid))
        {
            DataGrid myGrid = d as DataGrid;

            ObservableCollection<DataGridColumn> Columns = 
                 (ObservableCollection<DataGridColumn>)e.NewValue;

            if(Columns != null)
            {
                myGrid.Columns.Clear();

                if (Columns != null && Columns.Count > 0)
                {
                    foreach (DataGridColumn dataGridColumn in Columns)
                    {
                        myGrid.Columns.Add(dataGridColumn);
                    }
                }


                Columns.CollectionChanged += delegate(object sender,
                                 NotifyCollectionChangedEventArgs args)
                     {
                       if(args.NewItems != null)
                       {
                         foreach (DataGridColumn column 
                              in args.NewItems.Cast<DataGridColumn>())
                         {
                             myGrid.Columns.Add(column);
                         }
                       }

                       if(args.OldItems != null)
                       {
                         foreach (DataGridColumn column 
                                 in args.OldItems.Cast<DataGridColumn>())
                         {
                           myGrid.Columns.Remove(column);
                         }
                       }
                    };
            }
        }
    }
}

然后你将它附加到你这样的DataGrid（其中列是您的视图模型上的ObservableCollection属性）

Then you attach it to you DataGrid like this (Where columns is the an ObservableCollection property on your view model)

<Controls:DataGrid AutoGenerateColumns="False" 
            DataGridExtension.Columns="{Binding Columns}" />

如果您开始添加和删除列，我不知道它将如何回应，但是似乎从我的基本测试工作。祝你好运！

I'm not sure how well it is going to respond if you start adding and remove columns, but it seems to work from my basic testing. Good Luck!

这篇关于WPF MvvM DataGrid动态列的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！