我正在尝试使用 ImageShack API 上传图片。要使用它,我应该使用 multipart/form-data
POST
图像。我这样做了......
var postData = "";
var req = HttpWebRequest.Create("http://www.imageshack.us/upload_api.php");
req.Method = "POST";
req.ContentType = "multipart/form-data";
postData += "key=my_key_here&";
postData += "type=base64&";
// get base64 data from image
byte[] bytes = File.ReadAllBytes(@"D:\tmp\WpfApplication1\WpfApplication1\Images\Icon128.gif");
string encoded = Convert.ToBase64String(bytes);
postData += "fileupload=" + encoded;
byte[] reqData = Encoding.UTF8.GetBytes(postData);
using (Stream dataStream = req.GetRequestStream())
{
dataStream.Write(reqData, 0, reqData.Length);
}
var res = (HttpWebResponse)req.GetResponse();
var resStream = res.GetResponseStream();
var reader = new StreamReader(resStream);
string resString = reader.ReadToEnd();
txt1.Text = resString;
但是 ImageShack 提示说
<links>
<error id="parameter_missing">Sorry, but we've detected that unexpected data is received. Required parameter 'fileupload' is missing or your post is not multipart/form-data</error>
</links>
FileUpload 存在,我正在使用 multipart/form-data
怎么了?
更新:
新代码 http://pastebin.com/TN6e0CD8
发布数据 http://pastebin.com/fYE9fsxs
更新 2
我看了另一个问题Multipart forms from C# client .用边界修改了我的代码,删除了 expect 100 header ,我仍然无法让它工作......
ServicePointManager.Expect100Continue = false;
var boundary = "-----------------------------28520690214962";
var newLine = Environment.NewLine;
var propFormat = boundary + newLine +
"Content-Disposition: form-data; name=\"{0}\"" + newLine + newLine +
"{1}" + newLine + newLine;
var fileHeaderFormat = boundary + newLine +
"Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"" + newLine;
var req = (HttpWebRequest)HttpWebRequest.Create("http://jm/php/upload.php");
req.Method = WebRequestMethods.Http.Post;
req.ContentType = "multipart/form-data; boundary=" + boundary;
using (var reqStream = req.GetRequestStream()) {
var reqWriter = new StreamWriter(reqStream);
var tmp = string.Format(propFormat, "str1", "hello world");
reqWriter.Write(tmp);
tmp = string.Format(propFormat, "str2", "hello world 2");
reqWriter.Write(tmp);
reqWriter.Write(boundary + "--");
reqWriter.Flush();
}
var res = req.GetResponse();
using (var resStream = res.GetResponseStream()) {
var reader = new StreamReader(resStream);
txt1.Text = reader.ReadToEnd();
}
最佳答案
终于用下面的代码搞定了……
var boundary = "------------------------" + DateTime.Now.Ticks;
var newLine = Environment.NewLine;
var propFormat = "--" + boundary + newLine +
"Content-Disposition: form-data; name=\"{0}\"" + newLine + newLine +
"{1}" + newLine;
var fileHeaderFormat = "--" + boundary + newLine +
"Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"" + newLine;
var req = (HttpWebRequest)HttpWebRequest.Create("http://jm/php/upload.php");
req.Method = WebRequestMethods.Http.Post;
req.ContentType = "multipart/form-data; boundary=" + boundary;
using (var reqStream = req.GetRequestStream()) {
var reqWriter = new StreamWriter(reqStream);
var tmp = string.Format(propFormat, "str1", "hello world");
reqWriter.Write(tmp);
tmp = string.Format(propFormat, "str2", "hello world 2");
reqWriter.Write(tmp);
reqWriter.Write("--" + boundary + "--");
reqWriter.Flush();
}
var res = req.GetResponse();
using (var resStream = res.GetResponseStream()) {
var reader = new StreamReader(resStream);
txt1.Text = reader.ReadToEnd();
}
注意边界必须以 --
{boundary declared in ContentType} 开始,结束边界必须以 --
开始和结束。就我而言,我最初使用
var propFormat = boundary + newLine +
"Content-Disposition: form-data; name=\"{0}\"" + newLine + newLine +
"{1}" + newLine;
替换为
var propFormat = "--" + boundary + newLine +
"Content-Disposition: form-data; name=\"{0}\"" + newLine + newLine +
"{1}" + newLine;
一切正常
关于c# - 使用 HttpWebRequest POST 数据/使用 multipart/form-data 上传图像,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/3890754/