将 HttpResponseMessage 转换为字节数组

Question

我在将图像上传到服务器时遇到了一些麻烦

这是代码：

var uploadServer = api.Photo.GetUploadServer(123);

var c = new HttpClient();

var formData = new MultipartFormDataContent();
var requestContent = new MultipartFormDataContent();
var fileContent = new ByteArrayContent(File.ReadAllBytes("images/amogus.jpg"));
fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
{
    FileName = "amogus.jpg"
};
formData.Add(fileContent);


var responseFile = Encoding.ASCII.GetString(await c.PostAsync(uploadServer.UploadUrl, formData));

首先我得到了一个在那里上传图片的链接，然后我将图片添加到formData并尝试使用PostAync发送，在这一步我遇到了麻烦，因为PostAsync希望uploadUrl是byte []，但它是一个HttpResponseMessage。 我如何转换它？

这里还有错误信息：

参数 1：无法从 'System.Net.Http.HttpResponseMessage' 转换为 'byte[]'

Answer 1

您可以使用ReadAsStreamAsync然后将其传递给StreamReader以读取字符串。

您还缺少各种using块，您也可以 stream 将您的文件直接放入ByteArrayContent 。 requestContent似乎在这里没有使用。

static HttpClient c = new HttpClient();  // always keeps static or you could get socket exhaustion

using (var formData = new MultipartFormDataContent())
using (var fileContent = new StreamContent(File.Open("images/amogus.jpg", FileMode.Open, FileAccess.Read)))
{
    fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
    {
        FileName = "amogus.jpg"
    };
    formData.Add(fileContent);

    using (var response = await c.PostAsync(uploadServer.UploadUrl, formData))
    using (var responseStream = await response.Content.ReadAsStreamAsync())
    using (var reader = new StreamReader(responseStream, Encoding.ASCII))
    {
        var yourString = await responseStream.ReadToEndAsync();
        // do stuff with string
    }
}

你确定你想要ASCII而不是UTF8吗？ 如果是这样，您可以将整个事情缩短到这个

using (var formData = new MultipartFormDataContent())
using (var fileContent = new StreamContent(File.Open("images/amogus.jpg", FileMode.Open, FileAccess.Read)))
{
    fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
    {
        FileName = "amogus.jpg"
    };
    formData.Add(fileContent);

    using (var response = await c.PostAsync(uploadServer.UploadUrl, formData))
    {
        var yourString = await response.ReadAsStringAsync();
        // do stuff with string
    }
}