C#检测网络的连接状态

 

1. 方法定义

[DllImport("wininet.dll")]
private extern static bool InternetGetConnectedState( out int connectionDescription, int reservedValue ) ;

2. 方法说明
参数:
connectionDescription : 连接说明
reservedValue : 保留值
返回值:
true: On Line
false: Off Line

3. 调用方法
a. 你必须在你的code里引用System.Runtime.InteropServices,否则,会有编译错误
b. 定义一个变量 int I = 0;
c. 调用bool state = InternetGetConnectedState(out I,0);

完整的代码:
using System.Runtime.InteropServices;
namespace internet
{
public class Class1
{
[DllImport("wininet.dll")]
private extern static bool InternetGetConnectedState( out int connectionDescription, int reservedValue ) ;
public Class1(){}
private bool IsConnected()
{
int I=0;
bool state = InternetGetConnectedState(out I,0);
return state;
}
}
}