摘要:FileResult
在ASP.NET MVC 中，若要實現檔案文件等的上下傳，最簡單的就是使用FileResult。
FileResult 是基於檔案文件的一個ActionResult實作，目前在ASP.NET MVC 中定義了如下三個FileResult的實作 :
FileContentResult: Sends the contents of a binary file to the response.
FilePathResult: Sends the contents of a file to the response
FileStreamResult: Sends binary content to the response by using a Stream instance
在ASP.NET MVC 中，若要實現檔案文件等的上下傳，最簡單的就是使用FileResult。
- FileContentResult: Sends the contents of a binary file to the response.
protected virtual FileContentResult File(byte[] fileContents, string contentType, string fileDownloadName);
- FilePathResult: Sends the contents of a file to the response
protected virtual FilePathResult File(string fileName, string contentType, string fileDownloadName);
- FileStreamResult: Sends binary content to the response by using a Stream instance
protected virtual FileStreamResult File(Stream fileStream, string contentType, string fileDownloadName);
public FileContentResult fileContextResult(int productId = 2)
{
var prod = db.Products.FirstOrDefault(q => q.ProductID == productId);
return prod != null ? File(prod.ImageData, prod.ImageMimeType) : null;
}
public FilePathResult filePathResult()
{
ViewBag.Status = "FilePathResult";
string path = Server.MapPath("/Content/Guns/2.png");
return File(path, "image/png", "02.png");
}
public FileStreamResult fileStreamResult()
{
string path = Server.MapPath("/Content/Guns/2.png");
var image = new Bitmap(path);
MemoryStream stream = new MemoryStream();
image.Save(stream, ImageFormat.Jpeg);
stream.Seek(0, SeekOrigin.Begin);
return File(stream, "image/jpeg");
}
View
@ViewBag.Status
@Html.ActionLink("Download", "filePathResult")
上傳實作
Action :
[HttpPost]
public ActionResult Edit(Product product, HttpPostedFileBase image)
{
// 注意這邊須使用 HttpPostedFileBase 來接 multipart/form-data 格式的資料
if (ModelState.IsValid)
{
if (image != null)
{
product.ImageMimeType = image.ContentType;
product.ImageData = new byte[image.ContentLength];
image.InputStream.Read(product.ImageData, 0, image.ContentLength);
}
db.SaveProduct(product);
TempData["message"] = string.Format("{0} has been saved", product.Name);
return RedirectToAction("Index");
}
return View(product);
}
View :
@using (Html.BeginForm("Edit", "Admin", FormMethod.Post, new { enctype= "multipart/form-data" }))
{
@Html.EditorForModel();
@Html.ActionLink("Cancel", "Index") }
這邊的重點在於
Html.BeginForm("Edit", "Admin", FormMethod.Post, new { enctype= "multipart/form-data" })
必須先將 Form 宣告成 multipart，代表此「表單」包含多重欄位。詳細說明請參閱RFC 2388 。
PS:另外若非不得已請儘量避免在View中出現商業邏輯，如上方的 if else ，這邊僅是方便文章作呈現。
參考資訊
蒋金楠（Artech）的博客
RFC 2388
mime-types-full
石頭閒語 --HTML 5 -File API 簡易教學
Blogger : http://inblackbox.blogspot.tw/
幫忙宣傳--推廣的--(賣衣服的)
奇摩拍賣--http://tw.user.bid.yahoo.com/tw/user/Y7925877308&u=:Y7925877308&tp=