Grid View for ASP.NET Web Forms - How to edit a data table stored in a ViewState

This example demonstrates how to create a data table and grid control at runtime and use the grid's server-side events to update the data table.

Overview

Create a data table at runtime and save it to a ViewState.

private DataTable CustomDataSourse {
    get {
        if (dataTable != null)
            return dataTable;

        dataTable = ViewState["CustomTable"] as DataTable;
        if (dataTable != null)
            return dataTable;

        dataTable = new DataTable("CustomDTable");
        dataTable.Columns.Add("Id", typeof(Int32));
        dataTable.PrimaryKey = new DataColumn[] { dataTable.Columns[0] };
        dataTable.Columns.Add("Data", typeof(string));

        // ...
        ViewState["CustomTable"] = dataTable;

        return dataTable;
    }
}

Create a grid control at runtime and set its EnableCallbacks property to false to enable postback mode. This mode allows you to store data in a ViewState.

private void CreateGrid() {
    ASPxGridView grid = new ASPxGridView();
    grid.ID = "grid";
    this.Form.Controls.Add(grid);
    grid.EnableCallBacks = false;
    grid.KeyFieldName = "Id";
    // ...
}

Update the data table in the corresponding grid's event handlers and bind the grid to the updated data table.

private void UpdateData(ASPxGridView g) {
    ViewState["CustomTable"] = dataTable;
    g.DataBind();
}

Files to Review

• Default.aspx (VB: Default.aspx)
• Default.aspx.cs (VB: Default.aspx.vb)

Documentation

• Callbacks
• Grid View - How to implement CRUD operations with a custom data source

More Examples

• Grid View for ASP.NET Web Forms - How to edit a data table stored in a session
• Grid View for ASP.NET Web Forms - How to edit an in-memory data set with a master-detail relationship

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