为什么这个DateTime解析总是失败？

Question

谁能看到我在这里做错了什么？该Assert.IsTrue(parses)总是失败.

    [TestMethod]
    public void Can_Parse_To_DateTime()
    {
        DateTime expected = new DateTime(2011, 10, 19, 16, 01, 59);
        DateTime actual;

        string value = "Wed Oct 19 16:01:59 PDT 2011";
        string  mask = "ddd MMM dd HH:mm:ss xxx YYYY";

        bool parses = DateTime.TryParseExact(value, mask, 
                                             CultureInfo.InvariantCulture, 
                                             DateTimeStyles.None, 
                                             out actual);

        Assert.IsTrue(parses);
        Assert.AreEqual(expected, actual);
    }

我也这样尝试过,结果相同:

    [TestMethod]
    public void parsing()
    {
        DateTime expected = new DateTime(2011, 10, 19, 16, 01, 59);
        DateTime actual;

        string value = "Wed Oct 19 16:01:59 PDT 2011";
        string  mask = "ddd MMM dd HH:mm:ss YYYY"; // note removal of "xxx "

        value = value.Remove(20, 4);  // removal of the "PDT "
        bool parses = DateTime.TryParseExact(value, mask, 
                                             CultureInfo.InvariantCulture, 
                                             DateTimeStyles.None, 
                                             out actual);

        Assert.IsTrue(parses);
        Assert.AreEqual(expected, actual);
    }

Answer 1

正如马特·汉密尔顿所指出的，yyyy必须是小写。并且xxx完全无效。您始终可以使用反向方法测试您的格式字符串DateTime.ToString(format,CultureInfo.InvariantCulture)。