C# 影象處理(一)（影象縮放、螢幕擷取、影象合併、儲存影象）
轉自https://www.cnblogs.com/MRRAOBX/articles/6184646.html Image screen = getScreen(); // 擷取螢幕 saveImage(screen, screen.Size, @"d:\截圖.jpg"); // 儲存截圖
# region 影象處理功能函式
/// <summary>
/// 按指定尺寸對影象pic進行非拉伸縮放
/// </summary>
public static Bitmap shrinkTo(Image pic, Size S, Boolean cutting)
{
//建立影象
Bitmap tmp = new Bitmap(S.Width, S.Height); //按指定大小建立點陣圖
//繪製
Graphics g = Graphics.FromImage(tmp); //從點陣圖建立Graphics物件
g.Clear(Color.FromArgb(0, 0, 0, 0)); //清空
Boolean mode = (float)pic.Width / S.Width > (float)pic.Height / S.Height; //zoom縮放
if (cutting) mode = !mode; //裁切縮放
//計算Zoom繪製區域
if (mode)
S.Height = (int)((float)pic.Height * S.Width / pic.Width);
else
S.Width = (int)((float)pic.Width * S.Height / pic.Height);
Point P = new Point((tmp.Width - S.Width) / 2, (tmp.Height - S.Height) / 2);
g.DrawImage(pic, new Rectangle(P, S));
return tmp; //返回構建的新影象
}
//儲存影象pic到檔案fileName中，指定影象儲存格式
public static void SaveToFile(Image pic, string fileName, bool replace, ImageFormat format) //ImageFormat.Jpeg
{
//若影象已存在，則刪除
if (System.IO.File.Exists(fileName) && replace)
System.IO.File.Delete(fileName);
//若不存在則建立
if (!System.IO.File.Exists(fileName))
{
if (format == null) format = getFormat(fileName); //根據拓展名獲取影象的對應儲存型別
if (format == ImageFormat.MemoryBmp) pic.Save(fileName);
else pic.Save(fileName, format); //按給定格式儲存影象
}
}
//根據檔案拓展名，獲取對應的儲存型別
public static ImageFormat getFormat(string filePath)
{
ImageFormat format = ImageFormat.MemoryBmp;
String Ext = System.IO.Path.GetExtension(filePath).ToLower();
if (Ext.Equals(".png")) format = ImageFormat.Png;
else if (Ext.Equals(".jpg") || Ext.Equals(".jpeg")) format = ImageFormat.Jpeg;
else if (Ext.Equals(".bmp")) format = ImageFormat.Bmp;
else if (Ext.Equals(".gif")) format = ImageFormat.Gif;
else if (Ext.Equals(".ico")) format = ImageFormat.Icon;
else if (Ext.Equals(".emf")) format = ImageFormat.Emf;
else if (Ext.Equals(".exif")) format = ImageFormat.Exif;
else if (Ext.Equals(".tiff")) format = ImageFormat.Tiff;
else if (Ext.Equals(".wmf")) format = ImageFormat.Wmf;
else if (Ext.Equals(".memorybmp")) format = ImageFormat.MemoryBmp;
return format;
}
[DllImport("user32.dll")]
static extern bool GetCursorInfo(out CURSORINFO pci);
private const Int32 CURSOR_SHOWING = 0x00000001;
[StructLayout(LayoutKind.Sequential)]
struct POINT
{
public Int32 x;
public Int32 y;
}
[StructLayout(LayoutKind.Sequential)]
struct CURSORINFO
{
public Int32 cbSize;
public Int32 flags;
public IntPtr hCursor;
public POINT ptScreenPos;
}
/// <summary>
/// 擷取螢幕指定區域為Image，儲存到路徑savePath下，haveCursor是否包含滑鼠
/// </summary>
public static Image getScreen(int x = 0, int y = 0, int width = -1, int height = -1, String savePath = "", bool haveCursor = true)
{
if (width == -1) width = SystemInformation.VirtualScreen.Width;
if (height == -1) height = SystemInformation.VirtualScreen.Height;
Bitmap tmp = new Bitmap(width, height); //按指定大小建立點陣圖
Graphics g = Graphics.FromImage(tmp); //從點陣圖建立Graphics物件
g.CopyFromScreen(x, y, 0, 0, new Size(width, height)); //繪製
// 繪製滑鼠
if (haveCursor)
{
try
{
CURSORINFO pci;
pci.cbSize = Marshal.SizeOf(typeof(CURSORINFO));
GetCursorInfo(out pci);
System.Windows.Forms.Cursor cur = new System.Windows.Forms.Cursor(pci.hCursor);
cur.Draw(g, new Rectangle(pci.ptScreenPos.x, pci.ptScreenPos.y, cur.Size.Width, cur.Size.Height));
}
catch (Exception ex) { } // 若獲取滑鼠異常則不顯示
}
//Size halfSize = new Size((int)(tmp.Size.Width * 0.8), (int)(tmp.Size.Height * 0.8)); // 按一半尺寸儲存影象
if (!savePath.Equals("")) saveImage(tmp, tmp.Size, savePath); // 儲存到指定的路徑下
return tmp; //返回構建的新影象
}
/// <summary>
/// 縮放icon為指定的尺寸，並儲存到路徑PathName
/// </summary>
public static void saveImage(Image image, Size size, String PathName)
{
Image tmp = shrinkTo(image, size, false);
SaveToFile(tmp, PathName, true, null);
}
# endregion