我正在使用ASP.Net MVC 5，我想为我的用户个人资料创建一个头像。我不确定到目前为止我所做的事情是否正确，特别是出于安全考虑，所以我想得到一些建议。
在视图中：
@using (Html.BeginForm("ManageUser", "Account", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
<input type="file" name="file" />
<input type="submit" value="Add Avatar" />
}
在控制器中：
internal static bool SaveAvatar(User user, HttpPostedFileBase file)
{
if (file == null || file.ContentLength <= 0 || file.ContentLength > MAX_LENGTH)
return false;
//I think I should convert the file somehow instead of saving it
var path = HostingEnvironment.MapPath("~/img/avatar/") + string.Format("{0}.png", user.UserName);
file.SaveAs(path);
user.HasAvatar = true;
return true;
}
我有几个问题：
如果我正在做的是 TOTALLY 错误，并且您知道更好的来源以正确的方式学习，请指出我正确的方向。感谢。
答案 0 :(得分：8)
您可以使用此类将文件上传到服务器：
public static class FileUpload
{
public static char DirSeparator = System.IO.Path.DirectorySeparatorChar;
public static string FilesPath = HttpContext.Current.Server.MapPath("~\\Content" + DirSeparator + "Uploads" + DirSeparator);
public static string UploadFile(HttpPostedFileBase file)
{
// Check if we have a file
if (null == file) return "";
// Make sure the file has content
if (!(file.ContentLength > 0)) return "";
string fileName =DateTime.Now.Millisecond+ file.FileName;
string fileExt = Path.GetExtension(file.FileName);
// Make sure we were able to determine a proper extension
if (null == fileExt) return "";
// Check if the directory we are saving to exists
if (!Directory.Exists(FilesPath))
{
// If it doesn't exist, create the directory
Directory.CreateDirectory(FilesPath);
}
// Set our full path for saving
string path = FilesPath + DirSeparator + fileName;
// Save our file
file.SaveAs(Path.GetFullPath(path));
// Save our thumbnail as well
ResizeImage(file, 70, 70);
// Return the filename
return fileName;
}
public static void DeleteFile(string fileName)
{
// Don't do anything if there is no name
if (fileName.Length == 0) return;
// Set our full path for deleting
string path = FilesPath + DirSeparator + fileName;
string thumbPath = FilesPath + DirSeparator + "Thumbnails" + DirSeparator + fileName;
RemoveFile(path);
RemoveFile(thumbPath);
}
private static void RemoveFile(string path)
{
// Check if our file exists
if (File.Exists(Path.GetFullPath(path)))
{
// Delete our file
File.Delete(Path.GetFullPath(path));
}
}
public static void ResizeImage(HttpPostedFileBase file, int width, int height)
{
string thumbnailDirectory = String.Format(@"{0}{1}{2}", FilesPath, DirSeparator, "Thumbnails");
// Check if the directory we are saving to exists
if (!Directory.Exists(thumbnailDirectory))
{
// If it doesn't exist, create the directory
Directory.CreateDirectory(thumbnailDirectory);
}
// Final path we will save our thumbnail
string imagePath = String.Format(@"{0}{1}{2}", thumbnailDirectory, DirSeparator, file.FileName);
// Create a stream to save the file to when we're done resizing
FileStream stream = new FileStream(Path.GetFullPath(imagePath), FileMode.OpenOrCreate);
// Convert our uploaded file to an image
Image OrigImage = Image.FromStream(file.InputStream);
// Create a new bitmap with the size of our thumbnail
Bitmap TempBitmap = new Bitmap(width, height);
// Create a new image that contains are quality information
Graphics NewImage = Graphics.FromImage(TempBitmap);
NewImage.CompositingQuality = CompositingQuality.HighQuality;
NewImage.SmoothingMode = SmoothingMode.HighQuality;
NewImage.InterpolationMode = InterpolationMode.HighQualityBicubic;
// Create a rectangle and draw the image
Rectangle imageRectangle = new Rectangle(0, 0, width, height);
NewImage.DrawImage(OrigImage, imageRectangle);
// Save the final file
TempBitmap.Save(stream, OrigImage.RawFormat);
// Clean up the resources
NewImage.Dispose();
TempBitmap.Dispose();
OrigImage.Dispose();
stream.Close();
stream.Dispose();
}
}
您还可以使用ResizeImage方法保存照片的缩略图。在控制器中，我将以这种方式将文件名保存在数据库中：
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create(User user, HttpPostedFileBase file)
{
// TODO: Add insert logic here
user.Pictuer = FileUpload.UploadFile(file);
db.User.Add(user);
db.SaveChanges();
return RedirectToAction("Index");
}
对于转换上传的图片，您可以在UploadFile方法中使用this code：
System.Drawing.Image image1 = System.Drawing.Image.FromFile(@"C:\test.bmp");
// Save the image in JPEG format.
image1.Save(@"C:\test.jpg", System.Drawing.Imaging.ImageFormat.Jpeg);
// Save the image in GIF format.
image1.Save(@"C:\test.gif", System.Drawing.Imaging.ImageFormat.Gif);
// Save the image in PNG format.
image1.Save(@"C:\test.png", System.Drawing.Imaging.ImageFormat.Png);
答案 1 :(得分：0)
我发现这篇文章非常有用，我想分享我对Sirwan Afifi的优秀答案的实施。我需要调整大小功能来拍摄和返回图像，所以它有点不同。但是，我还添加了一个布尔值来保留图像的纵横比。
public static Image ResizeImage(Image img, int width, int height, bool preserveAspectRatio = false)
{
int newWidth;
int newHeight;
if (preserveAspectRatio)
{
int originalWidth = img.Width;
int originalHeight = img.Height;
float percentWidth = (float)width / (float)originalWidth;
float percentHeight = (float)height / (float)originalHeight;
float percent = percentHeight < percentWidth ? percentHeight : percentWidth;
//Rounding to get the set width to the exact pixel
newWidth = (float)originalWidth * percent < (float)width ? (int)(Math.Ceiling((float)originalWidth * percent)) : (int)((float)originalWidth * percent);
//Rounding to get the set height to the exact pixel
newHeight = (float)originalHeight * percent < (float)height ? (int)(Math.Ceiling((float)originalHeight * percent)) : (int)((float)originalHeight * percent);
}
else
{
newWidth = width;
newHeight = height;
}
// Create a new bitmap with the size
Bitmap TempBitmap = new Bitmap(newWidth, newHeight);
// Create a new image that contains are quality information
Graphics NewImage = Graphics.FromImage(TempBitmap);
NewImage.CompositingQuality = CompositingQuality.HighQuality;
NewImage.SmoothingMode = SmoothingMode.HighQuality;
NewImage.InterpolationMode = InterpolationMode.HighQualityBicubic;
// Create a rectangle and draw the image
Rectangle imageRectangle = new Rectangle(0, 0, newWidth, newHeight);
NewImage.DrawImage(img, imageRectangle);
return TempBitmap;
}