指定的转换无效使用后期绑定从 MailItem.AddressEntry 获取 MAPIOBJECT

Question

我正在尝试使用 Outlook 的后期绑定来获取 MailItem.AddressEntry 的 MAPIOBJECT。

我不断收到“调用目标已引发异常”和“指定的演员无效”的内部异常，我不知道为什么。 Google 搜索等上没有任何结果。

首先，我知道 MAPIOBJECT 已被弃用，并且通过智能感知不可见，但可以使用。

我可以毫无问题地获取对象，而无需后期绑定。

这是代码：

/// <summary>
/// Gets the MAPI Object from the AddressEntry of the new recipient.
/// </summary>
/// <param name="senderName">The name of the sender to add to the recipients.</param>
/// <param name="outlookApplication">The Outlook Application instance.</param>
private static object GetMapiObject(string senderName, object outlookApplication)
{
    var mailItem = InvokeMember("CreateItem", outlookApplication, new object[] { 0 });
    var recipients = GetProperty("Recipients", mailItem);
    var recipient = InvokeMember("Add", recipients, new object[] { senderName });

    InvokeMember("Resolve", recipient, new object[] {});
    var addressEntry = GetProperty("AddressEntry", recipient);

    var mapiObject = GetProperty("MAPIOBJECT", addressEntry); // Error occurs here.
    return mapiObject;
}

/// <summary>
/// Gets a property of an instance by its name
/// </summary>
/// <param name="propertyName">The property name to get.</param>
/// <param name="instance">The object to get the property from.</param>
/// <returns>The resulting object.</returns>
private static object GetProperty(string propertyName, object instance)
{
    Type type = instance.GetType();
    return type.InvokeMember(propertyName, BindingFlags.GetProperty, null, instance, new object[] { });
}

/// <summary>
/// Invoke an object by its method and type - takes parameters.
/// </summary>
/// <param name="method">The method to invoke.</param>
/// <param name="instance">The object that contains the method to invoke.</param>
/// <param name="parameters">The parameters to pass to the method.</param>
/// <returns>The resulting object.</returns>
private static object InvokeMember(string method, object instance, object[] parameters)
{
    try
    {
        Type type = instance.GetType();
        return type.InvokeMember(method, BindingFlags.InvokeMethod, null, instance, parameters);
    }
    catch (Exception ex)
    {
        switch (method)
        {
           case "SaveAsFile":
                throw new System.IO.IOException("Error occurred during \"SaveAsFile\" for attachments. Attachment filename may be too long. ", ex);                                                

            default:
                throw new TargetInvocationException("Handled error at Invoke Member. Method Name: " + method, ex);
        }
    }
}

Answer 1

除非您必须按原样使用 MAPI 界面，否则我强烈建议使用 MAPIEx 项目。

这使得我们的 MAPI 集成进行得非常非常顺利。

而且，最坏的情况是，源代码可以阐明特定问题，例如这个。

Answer 2

首先，MAPIOBJECT 并未被弃用，只是不可见。
其次，你的代码在哪里运行？如果它是 Outlook.exe 以外的 exe（即您的代码不在 COM 加载项中），则必须调用 MAPIInitialize()。