Corp and thumbnail of any size of image

Normally when we are writing a code for making image a Thumbnail actually we are loosing certain Quality of the picture but if we will follow below mentioned code then without loosing clarity of the image we can get it by given two method, In my case I had to upload the image in the server and show them in the gallery...



protected void btnUpload_Click(object sender, EventArgs e)
{
// Initialize variables
string sSavePath;
string sThumbExtension;
int intThumbWidth;
int intThumbHeight;

// Set constant values

sSavePath = "uploadedImages/";
sThumbExtension = "_thumb";
intThumbWidth = 160;
intThumbHeight = 120;

// If file field is not empty

if (fileUploader.PostedFile != null)
{
// Check file size (must not be 0)

HttpPostedFile myFile = fileUploader.PostedFile;
int nFileLen = myFile.ContentLength;
if (nFileLen == 0)
{
lblOutput.Visible = true;
lblOutput.Text = "No file was uploaded.";
return;
}

// Check file extension (must be JPG)

if (System.IO.Path.GetExtension(myFile.FileName).ToLower() != ".jpg")
{
lblOutput.Visible = true;
lblOutput.Text = "The file must have an extension of JPG";
return;
}

// Read file into a data stream

byte[] myData = new Byte[nFileLen];
myFile.InputStream.Read(myData, 0, nFileLen);

// Make sure a duplicate file does not exist.  If it does, keep on appending an

// incremental numeric until it is unique

string sFilename = System.IO.Path.GetFileName(myFile.FileName);

int file_append = 0;
while (System.IO.File.Exists(Server.MapPath(sSavePath + sFilename)))
{
file_append++;
sFilename = System.IO.Path.GetFileNameWithoutExtension(myFile.FileName)
+ file_append.ToString() + ".jpg";
}

// Save the stream to disk

System.IO.FileStream newFile
= new System.IO.FileStream(Server.MapPath(sSavePath + sFilename),
System.IO.FileMode.Create);
newFile.Write(myData, 0, myData.Length);
newFile.Close();

// Check whether the file is really a JPEG by opening it

System.Drawing.Image.GetThumbnailImageAbort myCallBack =
new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);
Bitmap myBitmap;
try
{
myBitmap = new Bitmap(Server.MapPath(sSavePath + sFilename));

// If jpg file is a jpeg, create a thumbnail filename that is unique.

file_append = 0;
string sThumbFile = System.IO.Path.GetFileNameWithoutExtension(myFile.FileName)
+ sThumbExtension + ".jpg";
while (System.IO.File.Exists(Server.MapPath(sSavePath + sThumbFile)))
{
file_append++;
sThumbFile = System.IO.Path.GetFileNameWithoutExtension(myFile.FileName) +
file_append.ToString() + sThumbExtension + ".jpg";
}

// Save thumbnail and output it onto the webpage

System.Drawing.Image myThumbnail
= myBitmap.GetThumbnailImage(intThumbWidth,
intThumbHeight, myCallBack, IntPtr.Zero);
myThumbnail.Save(Server.MapPath(sSavePath + sThumbFile));
filename = sThumbFile;
imgUser.ImageUrl = sSavePath + sThumbFile;
fileURL = sSavePath + sThumbFile;
// Displaying success information
lblOutput.Visible = true;
lblOutput.Text = "File uploaded successfully!";

// Destroy objects

myThumbnail.Dispose();
myBitmap.Dispose();
}
catch (ArgumentException errArgument)
{
// The file wasn't a valid jpg file
lblOutput.Visible = true;
lblOutput.Text = "The file wasn't a valid jpg file.";
System.IO.File.Delete(Server.MapPath(sSavePath + sFilename));
}
}

}


public bool ThumbnailCallback()
{
return false;
}