如何调用ManagementBaseObject方法或获取ManagementObject？

Question

TL/DR：

主要问题是:我得到一个ManagementBaseObject作为返回值。但是我不能调用它的方法，因为它没有InvokeMethod()成员，就像ManagementObject一样。那么，我如何调用它的成员方法呢？

阐述：

我打开一个BcdStore对象：

var bcdCls = new ManagementClass(@"root\WMI", "BcdStore", null); // OpenStore is a static method
var methodParams = bcdCls.GetMethodParameters("OpenStore");
methodParams["file"] = ""; // the default store
var results = bcdCls.InvokeMethod("OpenStore", methodParams, null);
Assert.IsNotNull(results);
var store = results["store"] as ManagementBaseObject;
Assert.IsNotNull(store);

但是这个对象是无用的：

// unfortunately, it is not a ManagementObject, so no InvokeMethod() is possible :-(
Assert.IsNull(store as ManagementObject);
store.InvokeMethod("EnumerateObjects", new object[] { 0 }); // Compilation error!
// ManagementBaseObject doesn't have an InvokeMethod member method!

Answer 1

可能是一个bug，因为PropertyData总是返回ManagementBaseObject，如果Type的值是CimType.Object (来源)，那么InvokeMethod的返回值也是ManagementBaseObject(来源)，除非使用ManagementOperationObserver。

没有观察者的例子：

// result is ManagementBaseObject
// result["__GENUS"] == 2
var result = bcdCls.InvokeMethod("OpenStore", methodParams, null);

一个观察者的例子：

var observer = new ManagementOperationObserver();

observer.ObjectReady += ObjectReady;
bcd.InvokeMethod(observer, "OpenStore", methodParams, null);

void ObjectReady(object sender, ObjectReadyEventArgs e)
{
    // e.NewObject is ManagementObject
    // e.NewObject["__GENUS"] == 2
}

在第二个片段中，我们有一个ManagementObject，因为ManagementBaseObject.GetBaseObject方法是在内部使用的(来源)。这样你就可以向微软汇报了。

最后，解决办法是：

var bcd = new ManagementClass(@"root\WMI", "BcdStore", null);
var openStoreParams = bcd.GetMethodParameters("OpenStore");

openStoreParams["File"] = "";

var openStoreResult = bcd.InvokeMethod("OpenStore", openStoreParams, null);
var openedStore = (ManagementObject)typeof(ManagementBaseObject)
    .GetMethod("GetBaseObject", BindingFlags.Static | BindingFlags.NonPublic)
    .Invoke(
        null,
        new object[]
        {
            typeof(ManagementBaseObject)
                .GetField("_wbemObject", BindingFlags.Instance | BindingFlags.NonPublic)
                .GetValue(openStoreResult["Store"]),
            bcd.Scope
        }
    );
var enumObjectsParams = openedStore.GetMethodParameters("EnumerateObjects");

enumObjectsParams["Type"] = 0;

var enumObjectsResult = openedStore.InvokeMethod("EnumerateObjects", enumObjectsParams, null);
var enumObjects = (ManagementBaseObject[])enumObjectsResult["Objects"];

foreach (var enumObject in enumObjects)
{
    // Do something
}