[英]Xamarin.Forms Upload Multiple Images with Data
我找到了幾個關於如何在 Xamarin 中上傳一個或多個圖像的教程。 但是,我還沒有找到如何發送包含一些衛星數據的每個圖像的多個圖像。
這是模型在服務器上的樣子:
public class AppFileDTO
{
public IFormFile File { get; set; }
public string CategoryName { get; set; }
public string CategoryDescription { get; set; }
public string Detail { get; set; }
}
但是控制器需要一個數據列表。 這是 Asp.Net Web Api 端點:
[HttpPost("UploadAppFiles/{id}")]
public async Task<IActionResult> UploadAppFiles(int id, IEnumerable<AppFileDTO> appFileDTOs)
{
...
}
我怎樣才能上傳這樣的東西?
我在堆棧溢出中找到了有關如何上傳帶有衛星數據的單個圖像的內容:
MultipartFormDataContent multiContent = new MultipartFormDataContent();
// Image 1
HttpContent fileStreamContent = new StreamContent(vm[0].File);
fileStreamContent.Headers.ContentDisposition = new
System.Net.Http.Headers.ContentDispositionHeaderValue("form-data")
{
Name = "File",
FileName = vm[0].File.FileName
};
fileStreamContent.Headers.ContentType = new
System.Net.Http.Headers.MediaTypeHeaderValue("application/octet-stream");
multiContent.Add(fileStreamContent );
// Satellite data, image 1
multiContent.Add(new StringContent(vm[0].CategoryName), "CategoryName");
multiContent.Add(new StringContent(vm[0].CategoryDescription), "CategoryDescription");
multiContent.Add(new StringContent(vm[0].Detail), "Detail");
// Send
var response = await client.PostAsync(url, multiContent);
你會如何上傳多個?
這就是我在 Postman 上上傳圖像以進行測試的方式,效果很好:
我認為您可以使用MultipartFormDataContent
添加多個圖像,並使用ContentDispositionHeaderValue.Parameters添加數據的值。
例如:
using (var content = new MultipartFormDataContent())
{
content.Add(CreateFileContent(vm[0]);
content.Add(CreateFileContent(vm[1]);
var response = await client.PostAsync(url, content);
response.EnsureSuccessStatusCode();
}
private StreamContent CreateFileContent(AppFileDTO appFileDTO)
{
var fileContent = new StreamContent(appFileDTO.File.Stream);//your file stream
fileContent.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data")
{
Name = "\"files\"",
FileName = "\"" + appFileDTO.File.FileName + "\"",
}; // the extra quotes are key here
fileContent.Headers.ContentType = new MediaTypeHeaderValue("image/jpeg");
fileContent.Headers.ContentDisposition.Parameters.Add(new NameValueHeaderValue("CategoryName",appFileDTO.CategoryName));
fileContent.Headers.ContentDisposition.Parameters.Add(new NameValueHeaderValue("CategoryDescription", appFileDTO.CategoryDescription));
fileContent.Headers.ContentDisposition.Parameters.Add(new NameValueHeaderValue("Detail", appFileDTO.Detail));
return fileContent;
}
並獲取 Content-Disposition 參數參考https://stackoverflow.com/a/30193961/10768653
我最終這樣做了:
MultipartFormDataContent multiContent = new MultipartFormDataContent();
// appFileDTOs[] contains the data that I am going to submit (image and satellite data)
// ------------------------ Object 1 -----------------------------------
// Image 1
HttpContent fileStreamContent1 = new StreamContent(image);
fileStreamContent1.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("form-data")
{
Name = "appFileDTOs[0].File",
FileName = "YourFileName.something" // e.g. image1.jpg
};
fileStreamContent1.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/octet-stream");
multiContent.Add(fileStreamContent1);
// Additional data for image 1
multiContent.Add(new StringContent(appFileDTOs[0].CategoryName), "appFileDTOs[0].CategoryName");
multiContent.Add(new StringContent(appFileDTOs[0].CategoryDescription), "appFileDTOs[0].CategoryDescription");
multiContent.Add(new StringContent(appFileDTOs[0].Detail), "appFileDTOs[0].Detail");
// ------------------------ Object 2 -----------------------------------
// Image 2
HttpContent fileStreamContent2 = new StreamContent(image);
fileStreamContent2.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("form-data")
{
Name = "appFileDTOs[1].File",
FileName = "YourFileName.something" // e.g. image2.jpg
};
fileStreamContent2.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/octet-stream");
multiContent.Add(fileStreamContent2);
// Additional data for image 2
multiContent.Add(new StringContent(appFileDTOs[1].CategoryName), "appFileDTOs[1].CategoryName");
multiContent.Add(new StringContent(appFileDTOs[1].CategoryDescription), "appFileDTOs[1].CategoryDescription");
multiContent.Add(new StringContent(appFileDTOs[1].Detail), "appFileDTOs[1].Detail");
// Send (url = url of api)
var response = await client.PostAsync(url, multiContent);
一次選擇一張圖像並將其與 CategoryName、CategoryDescription、Detail 一起添加到列表中,最后將其作為列表發送。
現在您可以發布包含多個圖像以及其他數據的列表
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