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使用C#将图像上传到Web API

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我试图通过POST将图像上传到Web服务 .

API文档说“通过POST上传文件,编码为"multipart/form-data"并包含一个名为"image"的POST文件,其中包含图像数据 . 图像必须是PNG,JPG或GIF类型 . ”

这是我的代码:

Bitmap    myImage = new Bitmap("myImage.jpg");
byte[] myFileData = (byte[])(new ImageConverter()).ConvertTo(myImage, typeof(byte[]));
string myBoundary = "------------------------" + DateTime.Now.Ticks;
var       newLine = Environment.NewLine;
string myContent = 
  "--" + myBoundary + newLine + 
  "content-disposition: form-data; name=\"image\"; filename=\"myImage.jpg\"" + newLine + 
  "Content-Type: image/jpeg" + newLine +
  "Content-Transfer-Encoding: binary" + newLine +
  newLine +
  Encoding.Default.GetString(myFileData) + newLine + 
  "--" + myBoundary + "--";

try {
    using (var httpClient = new HttpClient()) 
    using (var content = new StringContent(myContent, Encoding.Default, "multipart/form-data, boundary=" + myBoundary)) 
    using (var response = await httpClient.PostAsync("http://my_API_URL", content)) {
        string responseData = await response.Content.ReadAsStringAsync();
    }
}
catch (Exception myExp) { }

此代码尝试创建StringContent对象时引发异常 .

我对任何建议都没问题 . 我需要使用的API需要身份验证,通常使用WebClient和此语句解决:

client.Headers["Authorization"] = "Basic " + Convert.ToBase64String(Encoding.Default.GetBytes("my_API_key:"));

我可以使用任何其他形式的POST,如WebClient或HttpClient .

1 回答

  • 0

    最终有效的代码,万一有人在寻找相同的答案:

    Bitmap    myImage = new Bitmap("myImage.jpg");
    byte[] myFileData = (byte[])(new ImageConverter()).ConvertTo(myImage, typeof(byte[]));
    string myBoundary = "---------------------------7df3c13714f0ffc";
    var       newLine = Environment.NewLine;
    string  myContent =
      "--" + myBoundary + newLine + 
      "Content-Disposition: form-data; name=\"image\"; filename=\"myImage.jpg\"" + newLine +
      "Content-Type: image/jpeg" + newLine +
      newLine +
      Encoding.Default.GetString(myFileData) + newLine +
      "--" + myBoundary + "--";
    
    using (var client = new WebClient()) {
        try {
            client.Headers["Authorization"] = "Basic xxxxxx";
            client.Headers["Content-Type"]  = "multipart/form-data; boundary=" + myBoundary;
            client.UploadString(new Uri(myURL), "POST", myContent);
            totalAPICalls++;
        }
        catch { }
    }
    

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