Thursday, June 13, 2013

Customizing the Header

The page header is displayed at the top of every page in a web application. By default, the application namespace is displayed in the header, along with the standard theme logo.

Default page header and logo in a Code On Time web app.

Let’s customize the header.

Changing Header Text and Icon

Start the web app generator. Click on the project name, select settings, and press Features. In the Page Header text box, paste the following:

Property Value
Page Header
<span style="color:darkred;">Code On Time</span>

Press Finish and continue to regenerate the web app. When complete, click on the project name and press Develop to open the project in Visual Studio.

In the Solution Explorer, drop your logo image into ~\App_Themes\MyCompany folder.

Dropping the logo file into MyCompany theme folder.

Next, right-click on ~\App_Themes\MyCompany and press Add | Style Sheet. Leave the default name and press OK to create the file “StyleSheet.css”.

Adding a style sheet to the MyCompany theme folder.

Replace the contents with the following:

div#PageHeaderBar {
    background-image: url(colorlogo.png);
    height:42px;
    padding-top:30px;
}
    div#PageHeaderBar span {
        margin-left: 110px;
        font-size:32px;
    }
Save the file, and refresh the browser window. The new logo and header will be visible.

Code On Time web app with customized header text and logo.

Placing a Custom User Control in the Header

Sometimes it may be necessary to place dynamic content in the header area. Let’s create custom user control that will be displayed in the header on the Customers page.

Start the Project Designer. In the Project Explorer, right-click on Customers page node and press New Container.

Adding a new container to the Customers page.

Press OK to save the container with default settings. In the Project Explorer, right-click on Customers / c101 container and press Rename.

Renaming the new container.

Change the container name to “page”, and press Enter key to save.

User controls in the container “page” will be placed in special placeholders on the page when the app is generated. The name of the control instance determines the placeholder.

Right-click on Customers / page, and press New Control.

Adding a new control to the 'page' container.

Next to the User Control lookup on the form, click the New User Control icon.

Creating a new user control.

Assign a name to the new user control.

Property Value
Name CustomerHeader

Press OK to create the new user control. Press OK to save the properties of the control instance and have it added to the Customers / page container.

Right-click on Customers / page / control1 – CustomerHeader and press Rename.

Renaming the new control in the 'page' container.

Change the name to “header” and press Enter key to apply the change.

On the toolbar, press Browse. When generation is complete, navigate to the Customers page. The page will look like the picture below if there are no style sheet rules affecting the header area.

Unchanged custom user control replacing the default header text.

Dynamically Updating the Page Header

Let’s change the custom user control to make it display the primary key value from the selected data row of the Customers master data view.

Right-click on Customers / page / header – CustomerHeader and press Edit in Visual Studio.

Editing the control in Visual Studio.

Replace the existing code base after the <%@ Control %> element with the following:

<asp:UpdatePanel ID="UpdatePanel1" runat="server">
    <ContentTemplate>
        <asp:Button ID="Button1" runat="server" style="margin-left:120px;"
            Text="Get Customer Info" OnClick="Button1_Click" />
        <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
    </ContentTemplate>
</asp:UpdatePanel>

Right-click anywhere in the file, and press View Code. Add the following method:

C#:

protected void Button1_Click(object sender, EventArgs e)
{
    Control dataViewExtender = Parent.NamingContainer
        .FindControl("PageContentPlaceHolder").FindControl("view1Extender");
    Label1.Text = ((MyCompany.Web.DataViewExtender)dataViewExtender).SelectedValue;
}

Visual Basic:

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs)
    Dim dataViewExtender As Control = Parent.NamingContainer.
        FindControl("PageContentPlaceholder").FindControl("view1Extender")
    Label1.Text = CType(dataViewExtender, MyCompany.Web.DataViewExtender).SelectedValue
End Sub

Save the file. The event handler will respond to a click on the button “Button1”. First, it will find the instance of “view1Extender”. Next, the selected value will be copied to the label “Label1”.

Switch back to the browser. Navigate to the Customers page, and notice that the header text has been replaced with a button and a label.

Customized user control replacing the header element.

Select a customer, and press Get Customer Info button. The label will be updated with the selected Customer ID.

The header label is dynamically updated with the selected CustomerID.

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