.ContinueWith()和对象状态

Question

我在谈论哪一种更好(在美学、习惯性和性能方面)：

public async Task<string> DecryptAsync(string encrypted)
{
    SymmetricAlgorithm aes = this.GetAes();

    return await this.DecryptAsync(aes, encrypted).ContinueWith(
        (decryptTask, objectState) =>
        {
            (objectState as IDisposable)?.Dispose();
            return decryptTask.Result;
        },
        aes);
}

或

public async Task<string> DecryptAsync(string encrypted)
{
    SymmetricAlgorithm aes = this.GetAes();

    return await this.DecryptAsync(aes, encrypted).ContinueWith(decryptTask =>
    {
        aes.Dispose();
        return decryptTask.Result;
    });
}

主要区别在于，第二个变量在lambda中捕获aes变量，而第一个变量将其作为参数传递，然后将其转换为适当的类型。

第三个考虑，受Oxald和Servy的启发

public async Task<string> DecryptAsync(string encrypted)
{
    using (SymmetricAlgorithm aes = this.GetAes())
    {
        return await this.DecryptAsync(aes, encrypted);
    }
}

Answer 1

考虑使用“等待”代替ContinueWith。等待的结果等于Task.Result。可以使用using语句来处理aes：

public async Task<string> DecryptAsync(string encrypted)
{
    using (SymmetricAlgorithm aes = this.GetAes())
    {
        string decryptedText = await this.DecryptAsync(aes, encrypted);
        return decryptedText;
    };
}