asp.net (C #) Compressed pictures, you can specify the picture template high-width _ practical skills

Copy Code code as follows:

To generate a thumbnail function
Sequential parameters: Source diagram file flow, thumbnail store address, template width, template high
Note: Thumbnail size is controlled within the stencil area
public static void Makesmallimg (System.IO.Stream fromfilestream, String filesaveurl, System.Double templatewidth, System.Double templateheight)
{
Get a Picture object from a file and use the color management information embedded in the stream
System.Drawing.Image myimage = System.Drawing.Image.FromStream (Fromfilestream, true);
Thumbnail width, height
System.Double newwidth = myimage.width, newheight = myimage.height;
Wide in the template of the horizontal map
if (Myimage.width > Myimage.height | | | myimage.width = = myimage.height)
{
if (Myimage.width > Templatewidth)
{
Wide press template, high scaling
Newwidth = Templatewidth;
Newheight = Myimage.height * (newwidth/myimage.width);
}
}
Taller than the template of the vertical diagram
Else
{
if (Myimage.height > Templateheight)
{
High press stencil, wide scaling
Newheight = Templateheight;
Newwidth = Myimage.width * (newheight/myimage.height);
}
}
Get picture size
System.Drawing.Size mysize = new Size (int) newwidth, (int) newheight);
Create a new BMP picture
System.Drawing.Image bitmap = new System.Drawing.Bitmap (mysize.width, mysize.height);
Create a new artboard
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage (bitmap);
Set high quality interpolation method
G.interpolationmode = System.Drawing.Drawing2D.InterpolationMode.High;
Set high quality, low speed rendering smooth degree
G.smoothingmode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
Clear the canvas.
G.clear (Color.White);
Paint at a specified location
G.drawimage (MyImage, New System.Drawing.Rectangle (0, 0, bitmap.) Width, Bitmap. Height),
New System.Drawing.Rectangle (0, 0, Myimage.width, myimage.height),
System.Drawing.GraphicsUnit.Pixel);
Text watermark
System.Drawing.Graphics g=system.drawing.graphics.fromimage (bitmap);
System.Drawing.Font f=new Font ("Song Body", 10);
System.Drawing.Brush b=new SolidBrush (color.black);
g.DrawString ("Myohmine", f,b,10,10);
G.dispose ();
Picture watermark
System.Drawing.Image copyimage = System.Drawing.Image.FromFile (System.Web.HttpContext.Current.Server.MapPath (" Pic/1.gif "));
Graphics a = graphics.fromimage (bitmap);
A.drawimage (Copyimage, New Rectangle (bitmap). Width-copyimage.width,bitmap. Height-copyimage.height,copyimage.width, Copyimage.height), 0,0, Copyimage.width, Copyimage.height, GraphicsUnit.Pixel);
Copyimage.dispose ();
A.dispose ();
Copyimage.dispose ();
Save thumbnails
Bitmap. Save (Filesaveurl, System.Drawing.Imaging.ImageFormat.Jpeg);
G.dispose ();
Myimage.dispose ();
Bitmap. Dispose ();
}

Copy Code code as follows:

private void button2_click (object sender, EventArgs e)
{
Openfiledi Alog FileDialog = new OpenFileDialog ();
Filedialog.title = "Select Picture file";
//Filedialog.filter = "Excel Files (*.xls) |*.xls";
Filedialog.filterindex = 1;
if (filedialog.showdialog () = System.Windows.Forms.DialogResult.OK)
{

System.IO.FileStream file =sy Stem. Io. File.Open (Filedialog.filename,system.io.filemode.open);
System.IO.Stream strea = file;
file. Close ();
Makesmallimg (strea, thumbnail. jpg, 150, 150);
//file. Close ();

}
}