在asp.net中对gridview列进行排序c＃

Question

Can anyone tell the function to sort the columns of a gridview in c# asp.net.

The databound to gridview is from datacontext created using linq. I wanted to click the header of the column to sort the data.

Thanks!

Answer 1

There are 2 things you need to do to get this right.

1. Keep the sorting state is viewstate(SortDirection and SortExpression)
2. You generate the correct linq expression based on the current sorting state.

Manually handle the Sorting event in the grid and use this helper I wrote to sort by SortExpression and SortDirection:

public static IQueryable<T> SortBy<T>(IQueryable<T> source, string sortExpression, SortDirection direction) {
    if (source == null) {
        throw new ArgumentNullException("source");
    }

    string methodName = "OrderBy";
    if (direction == SortDirection.Descending) {
        methodName += "Descending";
    }

    var paramExp = Expression.Parameter(typeof(T), String.Empty);
    var propExp = Expression.PropertyOrField(paramExp, sortExpression);

    // p => p.sortExpression
    var sortLambda = Expression.Lambda(propExp, paramExp);

    var methodCallExp = Expression.Call(
                                typeof(Queryable),
                                methodName,
                                new[] { typeof(T), propExp.Type },
                                source.Expression,
                                Expression.Quote(sortLambda)
                            );

    return (IQueryable<T>)source.Provider.CreateQuery(methodCallExp);
}

db.Products.SortBy(e.SortExpression, e.SortDirection)

Check out my blog post on how to do this:

Answer 2

http://msdn.microsoft.com/en-us/library/ms745786.aspx

http://aspnet.4guysfromrolla.com/articles/012308-1.aspx

Answer 3

有关gridview中排序的更多信息可以在这里找到： MSDN Gridview排序用于获取数据的方法无关紧要，可以使用相同的排序。

Answer 4

add:

  AllowSorting="true"

to the <asp:GridView /> tag, that should do it

Answer 5

When I do that Alone it gives an error "The GridView 'GridView1' fired event Sorting which wasn't handled.

I've had that happen before... I've just created a throwaway handler, and then everything seemed to start working after that. Not the prettiest solution, but it worked for me.

That said, I didn't see any reference to a data source in your GridView code. You'll need something like this:

<asp:LinqDataSource ID="dsMyDataSource" runat="server"
DataContextTypeName="MyDataContext"
TableName="MyTable"
AllowSort="true" />

And then in your GridView:

<asp:GridView ID="gvMyGridView" runat="server" DataSourceID="dsMyDataSource" ... />

Answer 6

In the Properties Panel double Click on the Sorting Entry. A new Function will be created. In this Function write the Code to fill the Gridview. The only difference is to change the query based on GridViewSortEventArgs e

e.SortExpression and
e.SortDirection allways Ascending :-(

I hope this very short Answer helps

Answer 7

In Half Pseudocode for SQL Query

string Query= string.Empty;
string SortExpression = string.Empty;

// HDFSort is an HiddenField !!!

protected void SortCommand_OnClick(object sender, GridViewSortEventArgs e)
{
   SortExpression = e.SortExpression; 
   Query = YourQuery + " ORDER BY "+SortExpression +" "+ HDFSort.Value ;
   HDFSort.Value = HDFSort.Value== "ASC" ? "DESC" : "ASC";
   RefreshGridView();
}

protected void RefreshGridView()
{
   GridView1.DataSource = DBObject.GetData(Query);
   GridView1.DataBind();
}