不会求指导

[japzt320]

裁剪pictureBox1里800*400的图片显示到pictureBox2里并保存,参数好像不太对
public static void MakeThumbnail(string originalImagePath, string thumbnailPath, int width, int height, string mode, Boolean Replace, Boolean Delete)
{
System.Drawing.Image originalImage = System.Drawing.Image.FromFile(originalImagePath);
int towidth = width;
int toheight = height;
int x = 0;
int y = 0;
int ow = originalImage.Width;
int oh = originalImage.Height;
switch (mode)
{
case "HW":
break;
case "W":
toheight = originalImage.Height * width / originalImage.Width;
break;
case "H":
towidth = originalImage.Width * height / originalImage.Height;
break;
case "Cut":
if ((double)originalImage.Width / (double)originalImage.Height > (double)towidth / (double)toheight)
{
oh = originalImage.Height;
ow = originalImage.Height * towidth / toheight;
y = 0;
x = (originalImage.Width - ow) / 2;
}
else
{
ow = originalImage.Width;
oh = originalImage.Width * height / towidth;
x = 0;
y = (originalImage.Height - oh) / 2;
}
break;
default:
break;
}


System.Drawing.Image bitmap = new System.Drawing.Bitmap(towidth, toheight);
Graphics g = System.Drawing.Graphics.FromImage(bitmap);
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
g.Clear(Color.Transparent);
g.DrawImage(originalImage, new Rectangle(0, 0, 800, 400),
new Rectangle(1100,800,3000,2000),
GraphicsUnit.Pixel);


//originalImage.Dispose();








try
{
bitmap.Save(thumbnailPath, System.Drawing.Imaging.ImageFormat.Jpeg);
}
catch (System.Exception e)
{
throw e;
}
finally
{
originalImage.Dispose();
bitmap.Dispose();
g.Dispose();
}
}


private void button2_Click(object sender, EventArgs e)
{
MakeThumbnail(pictureBox1.Image, pictureBox2.Image,3000,1000,"W", false, true);


}