是什么導致了這個異常？我正在嘗試Moq用來模擬Microsoft.Office.Interop.Excel.Range. 我想在Range里面嵌套另一個嘲笑。但是當我嘗試訪問嵌套異常時，會拋出異常。例外無法將 [] 索引應(yīng)用于“Castle.Proxies.RangeProxy”類型的表達式代碼[TestMethod]public void RangeProxyIndexTest(){    // creating first range    var cell1 = new Moq.Mock<Range>();    cell1.Setup(c => c.Value2).Returns("1");    var range1Mock = new Moq.Mock<Range>();    range1Mock.SetupGet(r => r[1, Moq.It.IsAny<Object>()]).Returns(cell1.Object);    var range1 = range1Mock.Object;    // creating second range    var cell2 = new Moq.Mock<Range>();    cell2.Setup(c => c.Value2).Returns("2");    var range2Mock = new Moq.Mock<Range>();    range2Mock.SetupGet(r => r[1, Moq.It.IsAny<Object>()]).Returns(cell2.Object);    var range2 = range2Mock.Object;    // merging both ranges into 1    var range3Mock = new Moq.Mock<Range>();    range3Mock.SetupGet(r => r[1, Moq.It.IsAny<Object>()]).Returns(range1);    range3Mock.SetupGet(r => r[2, Moq.It.IsAny<Object>()]).Returns(range2);    var range3 = range3Mock.Object;    // testing succeeds    Assert.AreEqual("1", range1[1].Value2);    Assert.AreSame(range1, range3[1]);    Assert.AreEqual("2", range2[1].Value2);    Assert.AreSame(range2, range3[2]);    // exceptions are thrown here    Assert.AreEqual("1", range3[1][1].Value2);    Assert.AreEqual("2", range3[2][1].Value2);}