Question

有没有办法删除try-catch和使用if ???

进行相同的工作

    try
    {
        StorageFile sessionFile = await ApplicationData.Current.LocalFolder.CreateFileAsync(GUID, CreationCollisionOption.OpenIfExists);
        if (sessionFile == null)
            return Guid.Empty;

        using (IInputStream sessionInputStream = await sessionFile.OpenReadAsync())
        {
            var sessionSerializer = new DataContractSerializer(typeof(Guid));
            return (Guid)sessionSerializer.ReadObject(sessionInputStream.AsStreamForRead());
        }
    }
    catch (System.Xml.XmlException e)
    {
        return Guid.Empty;
    }

如果文件不是XML格式，或者??

，我认为我得到了Exception

Answer 1

不，基本上。没有TryReadObject方法，大多数序列化程序都不具备这种方法。您当然可以添加 TryReadObject 扩展名方法，即

public static T TryReadObject<T>(this IInputStream sessionInputStream, out T value)
{
    try
    {
        var serializer = new DataContractSerializer(typeof(T));
        using(var stream = sessionInputStream.AsStreamForRead())
        {
            value = (T)serializer.ReadObject(stream);
            return true;
        }
    }
    catch
    {
        value = default(T);
        return false;
    }
}

但这只会移动异常处理。但是你可以使用：

StorageFile sessionFile = await ApplicationData.Current.LocalFolder.CreateFileAsync(GUID, CreationCollisionOption.OpenIfExists);
if (sessionFile == null)
    return Guid.Empty;

using (IInputStream sessionInputStream = await sessionFile.OpenReadAsync())
{
    Guid val;
    return sessionInputStream.TryReadObject<Guid>(out val) ? val : Guid.Empty;
}

序列化XML，删除try-catch插入而不是if

1 个答案: