对非托管代码的调用
跨平台调用
l 把非托管 API 显示给托管代码
l 集成原有的系统和操作系统
Ø 存取注册表
Ø 播放声音
Ø 存取系统信息
§内存
§电池剩余时间

| Platform Invoke is not limited to calling COM components. In fact, you can use Platform Invoke to call any unmanaged API. Common uses for Platform Invoke include integrating legacy C DLLs into a managed application and making calls to the operating system to perform tasks not directly supported by the Compact Framework.
| Some examples of such tasks include accessing and modifying the registry, playing sounds, and interrogating system metrics like memory and remaining battery life.