Build a Release version of BandObjectLib and register it in the Global
Assembly Cache. The easiest way to do this is to open
BandObjectLib.sln in Visual Studio, set the active configuration to
Release and select 'Rebuild Solution' from the 'Build' menu. The
second project in the solution - RegisterLib - is a C++ utility
project that performs the 'gacutil /if BandObjectLib.dll' command that
puts assembly into GAC.
As you probably already know, Band Objects are COM components. And for
the .NET framework to find an assembly that implements a COM component
it must be either be registered in the GAC or located in the directory
of the client application. There are two possible client applications
for Band Objects - explorer.exe and iexplorer.exe. Explorer is located
in the windows directory and IE somewhere inside 'Program Files'. So
GAC is actually the only one option in this case. Thus .NET assemblies
that implement Band Objects should be registered in GAC and all
libraries they depend on - like BandObjectLib.dll - should also be
there.
Assemblies in the GAC must have strong names and thus key pairs are
required. I have provided the BandObjects.snk file with a key pair but
I encourage you to replace it with your own. See the sn.exe tool for
more details.
Create a new Windows Control Library project and call it SampleBars.
We are going to rely on the base functionality of BandObjectLib so we
have to add a reference to BandObjectLib\Relase\bin\BandObjectLib.dll.
As we are developing a 'Hello World Bar', rename UserControl1.cs and
the UserControl1 class inside it appropriately - into HelloWolrdBar.cs
and HelloWorldBar. Also put the following lines at the beginning of
HelloWorldBar.cs:
using BandObjectLib;
using System.Runtime.InteropServices;
Make HelloWorldBar class inherit BandObject instead of
System.Windows.Forms.UserControl. As I mentioned earlier, Band Objects
are COM components so we should use the Guid attribute. Use
guidgen.exe to generate your unique GUID or you can use the one I have
generated for you:
[Guid("AE07101B-46D4-4a98-AF68-0333EA26E113")]
We also have to sign our assembly with a strong name. You can do this
by putting the following line into AssemblyInfo.cs file:
[assembly: AssemblyKeyFile(@"..\..\..\BandObjects.snk")]
Now its time to decide what kind of Band Object we want to develop.
Lets make it an Explorer Toolbar as well as a Horizontal Explorer Bar
(also known as a Browser Communication Band). All we need to do to
implement this decision is to add custom BandObject attribute to our
HelloWorldBar class:
[Guid("AE07101B-46D4-4a98-AF68-0333EA26E113")]
[BandObject("Hello World Bar",
BandObjectStyle.Horizontal | BandObjectStyle.ExplorerToolbar,
HelpText = "Shows bar that says hello.")]
public class HelloWorldBar : BandObject
{ ...
That's enough to make our control available through 'View->Explorer
Bars' and 'View->Toolbars' explorer menus. It also takes care of menu
item text - "Hello World Bar", and hen the menu item is highlighted
status bar displays "Shows bar that says hello.". Don't you like
declarative programming and custom attributes?
Now it is time to open HelloWorldBar.cs in the Visual Studio Designer
and put some controls on it. Although in my version of HelloWorldBar I
decided to put a single button with 'Say Hello' caption on it you are
free to do something more personalized. I made the size of the button
equal to the size of the control's client area and also set its Anchor
property to the combination of all possible styles - 'Top, Bottom,
Left, Right'. The background color is 'HotTrack' and ForeColor is
'Info'.
The BandObject control has several properties specific to the Band
Objects (and so classes derived from it) - Title , MinSize, MaxSize
and IntegralSize. I set Title for HelloWorldBar to "Hello Bar" and
both MinSize and Size to '150, 24'. Oh, and in button's On Click event
handler I put code that displays a message box. This is what my final
code looks like (and most of it was generated by VS.Net):
using System;
using System.ComponentModel;
using System.Windows.Forms;
using BandObjectLib;
using System.Runtime.InteropServices;
namespace SampleBars
{
[Guid("AE07101B-46D4-4a98-AF68-0333EA26E113")]
[BandObject("Hello World Bar", BandObjectStyle.Horizontal
| BandObjectStyle.ExplorerToolbar, HelpText = "Shows bar that says hello.")]
public class HelloWorldBar : BandObject
{
private System.Windows.Forms.Button button1;
private System.ComponentModel.Container components = null;
public HelloWorldBar()
{
InitializeComponent();
}
protected override void Dispose( bool disposing )
{
if( disposing )
{
if( components != null )
components.Dispose();
}
base.Dispose( disposing );
}
#region Component Designer generated code
private void InitializeComponent()
{
this.button1 = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// button1
//
this.button1.Anchor = (((System.Windows.Forms.AnchorStyles.Top
| System.Windows.Forms.AnchorStyles.Bottom)
| System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.button1.BackColor = System.Drawing.SystemColors.HotTrack;
this.button1.ForeColor = System.Drawing.SystemColors.Info;
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(150, 24);
this.button1.TabIndex = 0;
this.button1.Text = "Say Hello";
this.button1.Click += new System.EventHandler(this.button1_Click);
//
// HelloWorldBar
//
this.Controls.AddRange(new System.Windows.Forms.Control[] { this.button1 });
this.MinSize = new System.Drawing.Size(150, 24);
this.Name = "HelloWorldBar";
this.Size = new System.Drawing.Size(150, 24);
this.Title = "Hello Bar";
this.ResumeLayout(false);
}
#endregion
private void button1_Click(object sender, System.EventArgs e)
{
MessageBox.Show("Hello, World!");
}
}
}
Ok, now we are ready to build SampleBars.dll but its not enough to see
it in explorer yet. We have to put our assembly into the GAC as well
as register it as a COM server. There are tools - gacutil.exe and
regasm.exe that do just this. The C++ utility project named Register
in my version of the SampleBars solution liberates me from using these
tools manually. It has no files in it, just the following post-build
command (debug version):
cd $(ProjectDir)..\bin\Debug
gacutil /if SampleBars.dll
regasm SampleBars.dll
Of cause you have to make sure that Register project is the last one
to be built in the solution using Project Dependencies / Build Order.
After building the solution, and executing the gacutil and regasm
commands, we are finally ready to start Explorer and see our toolbar
and explorer bar. And if you did everything right you should be able
to see something like the picture at the top of the article. On this
picture you can also see how HelloWorldBar looks in the Windows
Taskbar. To achieve this all you need to do is to modify BandObject
attribute adding the BandObjectStyle.TaskbarToolBar flag.