从 Xamarin 读取多部分数据

Question

我们需要将给定目录的 jpeg 文件发送到 Xamarin 应用。

下面是 Web API 中的代码。

public HttpResponseMessage DownloadMutipleFiles()
{
name = "DirectoryName";
var content = new MultipartContent();
var ids = new List<int> { 1,2};
var objectContent = new ObjectContent<List<int>>(ids, new System.Net.Http.Formatting.JsonMediaTypeFormatter());
content.Add(objectContent);
var file1Content = new StreamContent(new FileStream(@"D:Photos" + name+"\"+ "BL1408037_20191031124058_0.jpg", FileMode.Open));
file1Content.Headers.ContentType = System.Net.Http.Headers.MediaTypeHeaderValue.Parse("image/jpeg");
content.Add(file1Content);
var file2Content = new StreamContent(new FileStream(@"D:Photos" + name + "\" + "BL1408037_20191031124058_1.jpg", FileMode.Open));
file2Content.Headers.ContentType = System.Net.Http.Headers.MediaTypeHeaderValue.Parse("image/jpeg");
content.Add(file2Content);
var response = new HttpResponseMessage(HttpStatusCode.OK);
response.Content = content;
return response;
}

有人可以帮助如何从 Xamarin 应用程序阅读吗？提前致谢

Answer 1

这是我能够用来将图像作为多部分数据文件发送的功能！我只是获取了 Xamarin Essentials 图像选择器提供给我的字节数组，并将其传递给此函数：

public async Task SubmitImage(byte[] image, string imageName)
{
using (var client = new HttpClient())
{
string url = $"..."; // URL goes here
var token = Preferences.Get("AccessToken", "");
client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", token);
var stream = new MemoryStream(image);
var content = new StreamContent(stream);
//Without a name we can't actually put the file in IFormFile. We need the equivalent
//"name" value to be "file" (used if you upload via an <input> tag). We could call it
//anything but file is simple
content.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data")
{
FileName = imageName,
Name = "file"
};
content.Headers.ContentType = new MediaTypeHeaderValue("image/jpeg");
var multipartContent = new MultipartFormDataContent();
multipartContent.Add(content);
var result = await client.PostAsync(url, multipartContent);
}
}

您也可以使用控制台应用程序对此进行测试，只需从计算机发送图片，而不是通过应用程序执行此操作