在NUnit 2.5.8中使用TestContext时出现NullReferenceException

using NUnit.Framework;

[TestFixture]
public class MyTestClass
{
    private TestContext testContext;

    [TestFixtureSetUp]
    public void Initialize()
    {
        testContext = TestContext.CurrentContext;
    }

    [Test]
    public void MyTestMethod()
    {
        // 使用testContext对象进行测试
    }
}

using NUnit.Framework;

[TestFixture]
public class MyTestClass
{
    private TestContext testContext;

    [SetUp]
    public void SetUp()
    {
        testContext = TestContext.CurrentContext;
    }

    [Test]
    public void MyTestMethod()
    {
        // 使用testContext对象进行测试
    }
}