我在使用FormData API上传的网站中有一个canvas
元素。下面是我如何做到这一点:ReadAsMultipartAsync如何实际工作?
upload: function (e) {
var file = this.imagePreview.ui.canvas.get(0).toDataURL("image/jpeg")
.replace('data:image/jpeg;base64,', '');
if (file) {
var formData = new FormData();
formData.append('file', file);
$.ajax({
url: app.getApiRoot + 'UserFiles/',
type: "post",
data: formData,
processData: false,
contentType: false,
error: function() {
$("#file_upload_result").html('there was an error while submitting');
}
});
}
}
在那里我更换整个data:image/jpeg;base64,
业务按this post。
在后端我有以下多控制器:
public async Task<IHttpActionResult> PostUserFile()
{
string imageDir = ConfigurationManager.AppSettings["UploadedImageDir"];
var PATH = HttpContext.Current.Server.MapPath("~/" + imageDir);
var rootUrl = Request.RequestUri.AbsoluteUri.Replace(Request.RequestUri.AbsolutePath, String.Empty);
if (Request.Content.IsMimeMultipartContent())
{
var streamProvider = new CustomMultipartFormDataStreamProvider(PATH);
await Request.Content.ReadAsMultipartAsync(streamProvider).ContinueWith(t =>
{
if (t.IsFaulted || t.IsCanceled)
{
throw new HttpResponseException(HttpStatusCode.InternalServerError);
}
var files = streamProvider.FileData.Select(i =>
{
var info = new FileInfo(i.LocalFileName);
return new UserFile(User.Identity.GetUserId(), info.Name, rootUrl + "/" + imageDir + "/" + info.Name, info.Length/1024);
});
db.UserFiles.AddRange(files);
db.SaveChangesAsync();
});
return Ok();
}
else
{
throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotAcceptable, "This request is not properly formatted"));
}
}
我在哪里实现CustomMultipartFormDataStreamProvider
如下:
public class CustomMultipartFormDataStreamProvider : MultipartFormDataStreamProvider
{
public CustomMultipartFormDataStreamProvider(string path)
: base(path)
{ }
public override string GetLocalFileName(Headers.HttpContentHeaders headers)
{
var name = !string.IsNullOrWhiteSpace(headers.ContentDisposition.FileName) ?
headers.ContentDisposition.FileName :
"NoName";
// This is here because Chrome submits files in quotation
// marks which get treated as part of the filename and get escaped
return name.Replace("\"\"", string.Empty);
}
}
不幸的是,在供给到ReadAsMultipartAsync
方法streamProvider
的FileData
是空:
而且我觉得有趣的另一件事是,上传的二进制文件被转义,因为我从监视窗口中看到:
的%2f
对于/
字符转义序列。
我简直不能查明问题。任何人有任何建议?
请解释回答更多的细节。 –
请尝试学习如何使用Stackoverflow。编辑答案,不要在评论中添加信息。阅读此:https://stackoverflow.com/help/how-to-answer –
听起来很合理。让我今天晚些时候实施它,并回到你身边。 – seebiscuit