Drop down list as Itemtemplate within Gridview with Object Data Source Updating Database

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Introduction

Have you ever faced any problem in Grid view with Drop down list as Item Template and you try to update Grid view records using Object data source

From long time we used Data grid and its binding, also we saw how we can add drop down list as an Item template in it and it�s not new.

This article mainly deals with Display a drop down list inside a Grid view whose data source is binded and selected value is set based on ID. Updating grid row with object data source connecting business logic code.

I was just playing with Grid view and though of displaying a Drop down inside grid view with Grid view�s data source is set to Object data source which connects to Business logic code. There�s nothing new in displaying Drop down in Grid view and its data source can also be set and selected value can be set inline.

But when using Object data source with say Grid view or Form view and trying to update the records which includes a drop down as one template column then comes the problem.

While updating using object data source you can have a set of Update Parameters with each parameter may be

1) Control Parameter

2) Cookie Parameter

3) Form Parameter

4) Parameter

5) Profile Parameter

6) Query String Parameter

7) Session Parameter

You can set any update parameter in Object data source�s Update Parameters while you update database though Object data source connecting your business logic code.

Simple parameters can be set with Parameter. Did you ever though of how we can send selected value of Drop down list as a parameter with object data source.

If you think of sending through Control Parameter then it�s not possible. We can use Control parameter with its Id can be set to Grid view and not the drop down inside Grid view.

The solution which one I found is simply adding an update parameter in code behind. Let me explain how I did all these things.

On Grid view�s OnRowCommand Event just added an update parameter for Object data source�s Update Parameter collection. Based on the grid view�s command name is Update

Using the Code

protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{

        if (e.CommandName.Equals("Update"))
        {
            int state = 0;
            int index = int.Parse(e.CommandArgument.ToString());
            GridViewRow row = GridView1.Rows[index];
            DropDownList lstState = (DropDownList)row.FindControl("StateID");
            state = int.Parse(lstState.SelectedValue.ToString());
            ObjectDataSource1.UpdateParameters.Add("StateID", state.ToString());
        }      
}

1) Select a Gridview row based on the Gridview selection we will get the row index based on Grid view�s command event argument;s CommandArgument property.

2) Get the drop down list from the selected row through FindControl method on Gridview Row

3) Get the selected value of drop down and add parameter with selected value to Object datasource; s Update Parameters collection. OnrowUpdating Event of Gridview we can call Object datasource;s Update() method to invoke business logic Update method.

OnrowUpdating Event of Gridview we can call Object datasource;s Update() method to invoke business logic Update method.

protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
        ObjectDataSource1.Update();
}

Points of Interest

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