public void ConcatQueryString() { var mockAcsRequest = new MockAcsRequest(); Dictionary <String, String> tmpDic = null; // When parameters is null var result = MockAcsRequest.ConcatQueryString(tmpDic); Assert.Null(result); // when parameters is empty tmpDic = new Dictionary <String, String> { }; result = MockAcsRequest.ConcatQueryString(tmpDic); Assert.NotNull(result); // 非null 但是为空 Assert.Empty(result); // When parammters is not null tmpDic = new Dictionary <String, String> { { "foo", "bar" }, { "a", "A" }, { "n", null } }; result = MockAcsRequest.ConcatQueryString(tmpDic); Assert.Equal("foo=bar&a=A&n", result); }