Question

如何用C# 打开和保存BMP文件

思路：使用MenuStrip控件，当点击下拉菜单中的打开时，弹出打开对话框，点击另存为时，弹出另存为对话框
做法：建立Form1窗体，pictureBox1图片框，menuSrip1下拉列表控件
private void 打开图像ToolStripMenuItem_Click(object sender, EventArgs e)
{
Stream myStream;
OpenFileDialog openFileDialog1 = new OpenFileDialog();

openFileDialog1.InitialDirectory = "C:\\Documents and Settings\\Administrator\\My Documents\\My Pictures";
openFileDialog1.Filter = "BMP图形文件 (*.bmp)|*.bmp";
openFileDialog1.FilterIndex = 1;
openFileDialog1.RestoreDirectory = true;

if (openFileDialog1.ShowDialog() == DialogResult.OK)
{
if ((myStream = openFileDialog1.OpenFile()) != null)
{
pictureBox1.Image = new Bitmap(openFileDialog1.FileName);
/*至此可以打开图片，并显示在图片框控件当中，但是如果要对图片的二进制数据做进一步的操作，应该如何做？比如，打开的是一幅8位灰度图像，如何将它存入数组？*/
myStream.Close();
}
}

}

private void 另存为ToolStripMenuItem_Click(object sender, EventArgs e)
{

SaveFileDialog saveFileDialog1 = new SaveFileDialog();
saveFileDialog1.InitialDirectory = "C:\\Documents and Settings\\Administrator\\My Documents\\My Pictures";
saveFileDialog1.Filter = "Bitmap Image|*.bmp";
saveFileDialog1.Title = "保存图像";
saveFileDialog1.ShowDialog();

if(saveFileDialog1.FileName != "")
{

{

/*点击另存为按钮会引发对话框，但是不知道如何实际存入文件系统，此处应该写什么代码才能将图片存入磁盘内？*/
}
}

private void 保存图像ToolStripMenuItem_Click(object sender, EventArgs e)
{
//这里如何才能只点击保存按钮，就把当前的图像直接保存？
}

Answer 1

　　操作如下：
　　Bitmap _Bitmap = (Bitmap)Image.FromFile(@"c:\1.BMP");
BitmapData _BitmapData = _Bitmap.LockBits(new Rectangle(0, 0, _Bitmap.Width, _Bitmap.Height), ImageLockMode.ReadWrite, _Bitmap.PixelFormat);
byte[] _Value = new byte[_BitmapData.Stride * _BitmapData.Height];
Marshal.Copy(_BitmapData.Scan0, _Value, 0, _Value.Length);
写回去还是用 Marshal.Copy.

Answer 2

image to byte[]

Image photo = new Bitmap(selectPictureFile);
System.IO.MemoryStream ms = new System.IO.MemoryStream();
photo.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
byte[] imagedata = ms.GetBuffer();

byte[] to image

System.IO.MemoryStream ms = New IO.MemoryStream(imagedata)
Bitmap b = new Bitmap(ms);

后面的 保存
pictureBox2.Image.Save(saveFileDialog1.FileName , System.Drawing.Imaging.ImageFormat.Bmp);

至于你后面的直接保存，就留下前面的saveFileDialog1.FileName，然后
pictureBox2.Image.Save(保存的变量, System.Drawing.Imaging.ImageFormat.Bmp);
完了