c#使用账户密码 访问共享文件夹文件

如果共享文件夹需要使用账户密码才能访问，你可以使用 NetworkCredential 类来指定访问共享文件夹的账户和密码。例如：

string path = @"\\COMPUTER_NAME\SHARED_FOLDER\file.txt";
NetworkCredential credential = new NetworkCredential("USERNAME", "PASSWORD");
FileInfo file = new FileInfo(path);

// 使用账户密码访问文件
using (new NetworkConnection(Path.GetDirectoryName(path), credential))
{
    string content = File.ReadAllText(file.FullName);
}

其中，NetworkConnection 是一个自定义类，用于创建网络连接并使用指定的凭据进行身份验证。你需要在代码中添加以下代码：

class NetworkConnection : IDisposable
{
    string _networkName;

    public NetworkConnection(string networkName, NetworkCredential credentials)
    {
        _networkName = networkName;

        var netResource = new NetResource()
        {
            Scope = ResourceScope.GlobalNetwork,
            ResourceType = ResourceType.Disk,
            DisplayType = ResourceDisplaytype.Share,
            RemoteName = networkName
        };

        var result = WNetAddConnection2(netResource, credentials.Password, credentials.UserName, 0);

        if (result != 0)
        {
            throw new Win32Exception(result);
        }
    }

    ~NetworkConnection()
    {
        Dispose(false);
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected virtual void Dispose(bool disposing)
    {
        WNetCancelConnection2(_networkName, 0, true);
    }

    [DllImport("mpr.dll")]
    private static extern int WNetAddConnection2(NetResource netResource, string password, string username, int flags);

    [DllImport("mpr.dll")]
    private static extern int WNetCancelConnection2(string name, int flags, bool force);
}

[StructLayout(LayoutKind.Sequential)]
public class NetResource
{
    public ResourceScope Scope;
    public ResourceType ResourceType;
    public ResourceDisplaytype DisplayType;
    public int Usage;
    public string LocalName;
    public string RemoteName;
    public string Comment;
    public string Provider;
}

public enum ResourceScope : int
{
    Connected = 1,
    GlobalNetwork,
    Remembered,
    Recent,
    Context
};

public enum ResourceType : int
{
    Any = 0,
    Disk = 1,
    Print = 2,
    Reserved = 8,
}

public enum ResourceDisplaytype : int
{
    Generic = 0x0,
    Domain = 0x01,
    Server = 0x02,
    Share = 0x03,
    File = 0x04,
    Group = 0x05,
    Network = 0x06,
    Root = 0x07,
    Shareadmin = 0x08,
    Directory = 0x09,
    Tree = 0x0a,
    Ndscontainer = 0x0b
}

需要注意的是，这段代码使用了 WNetAddConnection2 和 WNetCancelConnection2 API 函数来创建和取消网络连接。因此，你需要在代码中添加 `using System.Runtime.InteropServices;` 来引用该命名空间。