在对对象集合或列表进行数据绑定时对网格视图进行排序

感谢您对排序的回答。我求助于LINQ来帮助动态排序。由于网格知道是对ASC还是DESC进行排序,以及对哪个字段进行排序,我使用了LINQ表达式。表达式执行排序,然后我简单地将这些结果绑定到我的网格视图。

我怀疑jQuery方法会更快,并且不需要完整的回发。

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();
    }
}

正确-您需要处理启动、排序列表并重新绑定。

或者,您可以考虑使用jQuery等javascript框架来处理排序客户端。

如果您遇到此错误:

尝试添加 .ToList<T>()

if (e.SortDirection == SortDirection.Ascending)
{
    GridViewTrackerLoans.DataSource = myGridResults.AsQueryable<T>().OrderBy(sortExpression).ToList<T>();
}
else
{
    GridViewTrackerLoans.DataSource = myGridResults.AsQueryable<T>().OrderByDescending(sortExpression).ToList<T>();
};

你可以为你的对象写一个比较:

private int CompareObject(YourObject object1, YourObject object2)
{
    int iReturnValue = 0;
    if ((object1 != null) && (object2 != null) &&
        (object1.SomeField != object2.SomeField))
    {
        iReturnValue = (object1.SomeField > object2.SomeField) ? 1 : -1;
    }
    return iReturnValue;
}

// Your list of data from the session or viewstate or whereever you have it stored.
lstObjects.Sort(CompareObject);

正确,您需要处理OnSorting事件并将AllowSorting属性设置为true。