构建插件式的应用程序框架(三)－动态加载

using System;
using System.Collections.Generic;
using System.Text;
using PluginFramework;
using System.Windows.Forms;
namespace FirstPlugin
{
public class FirstPlugin : IPlugin
{
private IApplication application = null;
private String name = "";
private String description = "";
        #region IPlugin Members

public IApplication Application
{
get { return application; }
set { application = value; }
}
public string Name
{
get { return name; }
set { name = value; }
}
public string Description
{
get { return description; }
set { description = value; }
}
public void Load()
{
if (application != null && application.BottomToolPanel != null)
{
//创建一个向主程序添加的ToolStrip
                ToolStrip sampleToolStrip = new ToolStrip();
ToolStripButton button = new ToolStripButton("Click Me");
button.Click += new EventHandler(button_Click);
sampleToolStrip.Items.Add(button);
//在主程序的底端添加ToolStrip
                application.BottomToolPanel.Controls.Add(sampleToolStrip);
}
}
void button_Click(object sender, EventArgs e)
{
MessageBox.Show("The first plugin");
}
//相关的文章主要讲动态加载，所以卸载就不实现了
        public void UnLoad()
{
throw new Exception("The method or operation is not implemented.");
}
public event EventHandler<EventArgs> Loading;

#endregion
    }
}

private void toolStripButton1_Click(object sender, EventArgs e)
{
//动态加载插件，为了方便起见，我直接给出插件所在的位置
    String pluginFilePath = Path.GetDirectoryName(Application.ExecutablePath)
+ """plugins""FirstPlugin.dll";
Assembly assembly = Assembly.LoadFile(pluginFilePath);
//得到Assembly中的所有类型
    Type[] types = assembly.GetTypes();
//遍历所有的类型，找到插件类型，并创建插件实例并加载
    foreach (Type type in types)
{
if (type.GetInterface("IPlugin") != null)//判断类型是否派生自IPlugin接口
        {
IPlugin plugin = (IPlugin)Activator.CreateInstance(type);//创建插件实例
            plugin.Application = this;
plugin.Load();
}
}
}