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When to populate a sorted asp: gridview?

I tried to ask this question in several ways. This is a difficult question to answer because you must understand what is happening.

When do I populate the gridview?

The answer to the question during Page_Load, if not PostBack:

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
       DataSet ds = GetStuffToShow();
       GridView1.DataSource = ds;
       GridView1.DataBind();
    }
}

The problem is that if this is a postback, the grid is not populated. The reason the grid is not full is because we disabled the viewstate of the grid.

So don't look at IsPostBack

We need to always fill in the grid, postback or not:

protected void Page_Load(object sender, EventArgs e)
{
    DataSet ds = GetStuffToShow();
    GridView1.DataSource = ds;
    GridView1.DataBind();
}

The problem is that if the user sorts the column, the event OnSortingis called after both Page_Init, and Page_Load:

protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
    DataSet ds = GetStuffToShow(e.SortExpression, e.SortDirection);
    GridView1.DataSource = ds;
    GridView1.DataBind();
}

we performed two database queries when only one was required.

, DataSet , .

, OnSorting . (Page_Load):

protected void Page_Load(object sender, EventArgs e)
{
    if (AGridViewOnSortingEventIsntBeingRaised)
    {
       DataSet ds = GetStuffToShow();

       StoreTheDatasetInTheSessionSomehowInCaseTheyCallSortInTheFuture(ds);

       GridView1.DataSource = ds;
       GridView1.DataBind();
    }
}

protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
    DataSet ds = GetDataSetOutOfSessionSomehowThatDamnWellBetterBeThere();

    SomehowSortAReadOnlyDisconnectedDataSet(ds, e.SortExpression, e.SortDirection);

    GridView1.DataSource = ds;
    GridView1.DataBind();
}

, viewstate GridView. , asp:GridView base64, ( ).

, GridView , , . Page_Load (.. Page_Init). , - .

protected void Page_Init(object sender, EventArgs e)
{
    if (AGridViewOnSortingEventIsntBeingRaised)
    {
       DataSet ds = GetStuffToShow();

       StoreTheDatasetInTheSessionSomehowInCaseTheyCallSortInTheFuture(ds);

       GridView1.DataSource = ds;
       GridView1.DataBind();
    }
}

, GetStuffToShow , , Page_Init

, . . , , asp.net

+5
3

, , , GridView , ( GridView "--" ):

    protected void Page_Load(object sender, EventArgs e)
    {
        DataSet ds = GetStuffToShow();
        GridView1.DataSource = ds;
        GridView1.DataBind();
    }

    protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
    {
        // If the sorting column is the same as the previous one, 
        // then change the sort order.
        if (SortExpression.Value.Equals(e.SortExpression))
        {
            SortDirection.Value = SortDirection.Value.Equals("ASC") ? "DESC" : "ASC";
        }
        // If sorting column is another column, 
        // then specify the sort order to "Ascending".
        else
        {
            SortExpression.Value = e.SortExpression;
            SortDirection.Value = "ASC";
        }

        var sortedView = new DataView(<convert your DataSet to a DataTable>)
            { Sort = string.Format("{0} {1}", this.SortExpression.Value, this.SortDirection.Value) };
        GridView1.DataSource = sortedView;

        GridView1.DataBind();
    }

, SortDirection SortExpression . DataSet.

, Page_Init, . , .

0

Gridview.DataBind() Page.Pre_Render, Button/Sorting. , .

, , "Store-The-Dataset-In-The-Session-Somehow-In-Case-They-Call-Sort-In-The-Future" "" "<23" "".

0

Gridview Needdatasource , - , . , , databind, needdatasource

0
source

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