C# 5.0 Programmer's Reference

726 ❘ APPENDIX A Solutions to Exercises
imagePictureBox.ClientSize.Width,
imagePictureBox.ClientSize.Height);
imagePictureBox.Image = Picture;
// Look for assemblies.
foreach (string filename in
Directory.GetFiles(Application.StartupPath, "*.dll"))
{
// Load this assembly.
Assembly dll = Assembly.LoadFile(filename);
// Look for classes that have Draw methods.
foreach (Type type in dll.GetTypes())
{
// Make sure this is a class.
if (!type.IsClass) continue;
// Find the Draw method.
MethodInfo methodInfo = type.GetMethod("Draw");
if (methodInfo == null) continue;
// Make sure it's a static method.
if (!methodInfo.IsStatic) continue;
// Make sure it takes a Graphics object as a parameter.
ParameterInfo[] parameters = methodInfo.GetParameters();
if (parameters.Length != 1) continue;
if (parameters[0].ParameterType != typeof(Graphics)) continue;
// We can use this method!
// Get the class's DisplayName atttribute.
Attribute attribute =
type.GetCustomAttribute(typeof(DisplayNameAttribute));
string toolName;
if (attribute == null) toolName = type.Name;
else
{
DisplayNameAttribute attr = attribute as DisplayNameAttribute;
toolName = attr.DisplayName;
}
// Create a menu item for this method.
ToolStripItem item = toolsMenu.DropDownItems.Add(toolName);
item.Tag = methodInfo;
}
}
}
// Set a Click event handler for the menu item.
item.Click += item_Click;
www.it-ebooks.info