C＃反射：我如何调用带有输出参数的方法？ [英] c# reflection: How can I invoke a method with an out parameter?

问题描述

我要揭露WebClient.DownloadDataInternal方法象下面这样：

  [标记有​​ComVisible特性（真）]
公共类MyWebClient：Web客户端
{
    私人MethodInfo的_DownloadDataInternal;    公共MyWebClient（）
    {
        _DownloadDataInternal = typeof运算（Web客户端）.GetMethod（DownloadDataInternal，BindingFlags.NonPublic可| BindingFlags.Instance）;
    }    公众的byte [] DownloadDataInternal（URI地址，出的WebRequest请求）
    {
        _DownloadDataInternal.Invoke（这一点，新的对象[] {地址，出请求}）;
    }}
 

WebClient.DownloadDataInternal有一个输出参数，我不知道如何调用它。
帮帮我！

解决方案

 公共类MyWebClient：Web客户端
{
    代表的byte [] DownloadDataInternal（URI地址，WebRequest的出请求）;    DownloadDataInternal downloadDataInternal;    公共MyWebClient（）
    {
        downloadDataInternal =（DownloadDataInternal）Delegate.CreateDelegate（
            typeof运算（DownloadDataInternal）
            这个，
            typeof运算（Web客户端）.GetMethod（
                DownloadDataInternal
                BindingFlags.NonPublic可| BindingFlags.Instance））;
    }    公众的byte [] DownloadDataInternal（URI地址，出的WebRequest请求）
    {
        返回downloadDataInternal（地址，出请求）;
    }
}
 

I want expose WebClient.DownloadDataInternal method like below:

[ComVisible(true)]
public class MyWebClient : WebClient
{
    private MethodInfo _DownloadDataInternal;

    public MyWebClient()
    {
        _DownloadDataInternal = typeof(WebClient).GetMethod("DownloadDataInternal", BindingFlags.NonPublic | BindingFlags.Instance);
    }

    public byte[] DownloadDataInternal(Uri address, out WebRequest request)
    {
        _DownloadDataInternal.Invoke(this, new object[] { address, out request });
    }

}

WebClient.DownloadDataInternal has a out parameter, I don't know how to invoke it. Help!

解决方案

public class MyWebClient : WebClient
{
    delegate byte[] DownloadDataInternal(Uri address, out WebRequest request);

    DownloadDataInternal downloadDataInternal;

    public MyWebClient()
    {
        downloadDataInternal = (DownloadDataInternal)Delegate.CreateDelegate(
            typeof(DownloadDataInternal),
            this,
            typeof(WebClient).GetMethod(
                "DownloadDataInternal",
                BindingFlags.NonPublic | BindingFlags.Instance));
    }

    public byte[] DownloadDataInternal(Uri address, out WebRequest request)
    {
        return downloadDataInternal(address, out request);
    }
}

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