数据绑定对象的集合或列表排序时，一个gridview [英] Sorting a gridview when databinding a collection or list of objects

问题描述

我有一个GridView通过以下方式设置：

• 绑定到列表＆LT; T＆GT; 在code-背后（我用我自己的自定义BOL）


• HTML页面上没有任何数据源对象


• 在我选择（即 SORTEX pression s的所有设置是否正确）
每一列排序

不过，我收到以下错误消息：

  

GridView控件myGridView解雇事件排序这是不处理的。

什么是我得到的最好方法我列表＆LT; T＆GT; 允许排序

我怀疑，这将有指定的 OnSorting 属性的功能，即要做到：

  OnSorting =MySortingMethod
 

解决方案

感谢您对排序你的答案。我转过身来，LINQ帮助排序动态。由于电网知道是否排序ASC或DESC，哪些领域，我用了LINQ防爆pression。防爆pression进行排序，然后我只需绑定了这些结果，以我的GridView控件。

我怀疑jQuery的方法会更快，也不会需要一个完整的回发。

 使用System.Linq.Ex pressions;公共SortDirection GridViewSortDirection
{
    得到
    {
        如果（的ViewState [sortDirection] == NULL）
            的ViewState [sortDirection] = SortDirection.Ascending;        回报（SortDirection）的ViewState [sortDirection];
    }
    集合{的ViewState [sortDirection] =值; }
}保护无效gridView_Sorting（对象发件人，GridViewSortEventArgs E）
{
    //重新运行查询，使用LINQ基础上，ARG的对象进行排序。
    //执行使用给定的约束搜索
    //你可能有这样的保存在会话，而不是再次查询数据存储
    清单＆LT; T＆GT; myGridResults = PerfomSearch（）;
    如果（myGridResults！= NULL）
    {
        VAR参数=前pression.Parameter（typeof运算（T），e.SortEx pression）;
        VAR SORTEX pression =前pression.Lambda＆LT;＆Func键LT; T，对象＆gt;＆GT;（防爆pression.Convert（前pression.Property（参数，e.SortEx pression）的typeof（对象）），参数）;
        如果（GridViewSortDirection == SortDirection.Ascending）
        {
            myGridView.DataSource = myGridResults.AsQueryable＆LT; T＆GT;（）排序依据（SORTEX pression）;
            GridViewSortDirection = SortDirection.Descending;
        }
        其他
        {
            myGridView.DataSource = myGridResults.AsQueryable＆LT; T＆GT;（）OrderByDescending（SORTEX pression）;
            GridViewSortDirection = SortDirection.Ascending;
        };
        myGridView.DataBind（）;
    }
}
 

I have a GridView set up in the following way:

• bound to a List<T> in code-behind (I am using my own custom BOL)
• no DataSource Object on the HTML page
• sortable on each column that I choose (the SortExpressions are all set correctly)

However, I am getting the following error message:

The GridView 'myGridView' fired event Sorting which wasn't handled.

What is the best way for me to get my List<T> to allow sorting?

I am suspecting that it will have to do with specifying a function for the OnSorting attribute, i.e.:

OnSorting = "MySortingMethod"

解决方案

Thank you for your answers on the sorting. I turned to LINQ to help sort dynamically. Since the grid knows whether to sort ASC or DESC, and which field, I used a LINQ Expression. The Expression performed the sorting, and then I simply bound those results to my gridview.

I suspect the jQuery method would be faster, and wouldn't require a full postback.

using System.Linq.Expressions;

public SortDirection GridViewSortDirection
{
    get
    {
        if (ViewState["sortDirection"] == null)
            ViewState["sortDirection"] = SortDirection.Ascending;

        return (SortDirection)ViewState["sortDirection"];
    }
    set { ViewState["sortDirection"] = value; }
}

protected void gridView_Sorting(object sender, GridViewSortEventArgs e)
{
    //re-run the query, use linq to sort the objects based on the arg.
    //perform a search using the constraints given 
    //you could have this saved in Session, rather than requerying your datastore
    List<T> myGridResults = PerfomSearch();


    if (myGridResults != null)
    {
        var param = Expression.Parameter(typeof(T), e.SortExpression);
        var sortExpression = Expression.Lambda<Func<T, object>>(Expression.Convert(Expression.Property(param, e.SortExpression), typeof(object)), param);


        if (GridViewSortDirection == SortDirection.Ascending)
        {
            myGridView.DataSource = myGridResults.AsQueryable<T>().OrderBy(sortExpression);
            GridViewSortDirection = SortDirection.Descending;
        }
        else
        {
            myGridView.DataSource = myGridResults.AsQueryable<T>().OrderByDescending(sortExpression);
            GridViewSortDirection = SortDirection.Ascending;
        };


        myGridView.DataBind();
    }
}

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