CODEWITHSUNDEEP
asp.netwebforms
TheHvidsten
TheHvidsten

Reputation: 4418

GridView with CheckBox, CheckedChanged always true the first time

I have a pretty standard GridView. This includes a TemplateField with a checkbox. I set the checkboxes to checked/unchecked based on values in a database. The checkboxes have a CheckedChanged event. After the page has loaded the first time I click a checkbox that is checked. The CheckedChanged event fires, but the CheckBox always has Checked = true. Any subsequent clicks on checkboxes, and the information in the event is correct.

What is causing this?

.aspx

<asp:UpdatePanel runat="server">
    <ContentTemplate>
        <asp:GridView ID="MyGV" runat="server" DataKeyNames="Id" OnRowCreated="MyGV_RowCreated" AutoGenerateColumns="false">
            <Columns>
                <asp:TemplateField HeaderText="My checkboxes">
                    <ItemTemplate>
                        <asp:CheckBox ID="MyCheckBox" runat="server" OnCheckedChanged="MyCheckBox_CheckedChanged" AutoPostBack="true" />
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        </asp:GridView>
    </ContentTemplate>
</asp:UpdatePanel>

Code behind

protected void Page_Load(object sender, EventArgs e) {
    if (!IsPostBack) {
        MyGV.DataSource = myfetcheddata;
        MyGV.DataBind();
    }
}

protected void MyGV_RowCreated(object sender, GridViewRowEventArgs e) {
    CheckBox MyCheckBox = (CheckBox)e.Row.FindControl("MyCheckBox");
    if (isSomethingMarkedInDatabase) {
        MyCheckBox.Checked = true;
    }
}

protected void MyCheckBox_CheckedChanged(object sender, EventArgs e) {
    CheckBox MyCheckBox = (CheckBox)sender;
    if (MyCheckBox.Checked) {
        // This is always run the first time a checkbox is clicked, whether or not it was checked or not in the first place. Any subsequent clicks on checkboxes has correct behaviour here.
    } else {
    }
}

Upvotes: 1

Views: 896

Answers (1)

Tim Schmelter
Tim Schmelter

Reputation: 460028

Why do you use RowCreated instead of RowDataBound? RowCreated is always triggered, so on each and every postback, before the events are triggered. So maybe it is fixed if you move that code to RowDataBound which is only called after grid.DataBind().

protected void MyGV_RowDataBound(object sender, GridViewRowEventArgs e) {
    if (row.RowType == DataControlRowType.DataRow){
        CheckBox MyCheckBox = (CheckBox)e.Row.FindControl("MyCheckBox");
        MyCheckBox.Checked = isSomethingMarkedInDatabase;
    }
}

You can access the datasource in RowDataBound. If you want to evaluate a field in the record you have to cast e.Row.DataItem to the actual type(f.e. a DataRowView).

Upvotes: 1

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