C#軟件開發實例.私人訂制自己的屏幕截圖工具（七）添加放大鏡的功能

上一篇：C#軟件開發實例.私人訂制自己的屏幕截圖工具（六）添加配置管理功能

由於截圖時可能需要精確截取某一部分，所以需要放大鏡的功能，這樣截取的時候才更容易定位截圖的位置。

添加PictureBox，name屬性設置為“pictureBox_zoom”；

在“Form1_Load”事件處理函數中添加以下代碼：

//設置放大鏡的大小
            this.pictureBox_zoom.Width = this.ZoomBoxWidth;
            this.pictureBox_zoom.Height = this.ZoomBoxHeight;

在“ExitCutImage”方法中添加代碼：

在“Form1_MouseUp”事件處理函數中添加代碼：

在“ShowForm”方法的else條件最後添加代碼：

if (this.ZoomBoxVisible)
                {
                    UpdateCutInfoLabel(UpdateUIMode.ShowZoomBox);
                    this.pictureBox_zoom.Show();
                }

在“UpdateCutInfoLabel”函數最後添加以下代碼：

if (this.pictureBox_zoom.Visible || (updateUIMode & UpdateUIMode.ShowZoomBox) != UpdateUIMode.None)
            {
                Point zoomLocation = new Point(MousePosition.X + 15, MousePosition.Y + 22);
                if (zoomLocation.Y + this.pictureBox_zoom.Height > this.Height)
                {
                    if (zoomLocation.X + this.pictureBox_zoom.Width > this.Width)
                    {
                        zoomLocation = new Point(MousePosition.X - this.pictureBox_zoom.Width - 10, MousePosition.Y - this.pictureBox_zoom.Height - 10);
                    }
                    else
                    {
                        zoomLocation = new Point(MousePosition.X + 15, MousePosition.Y - this.pictureBox_zoom.Height - 15);
                    }
                }
                else
                {
                    if (zoomLocation.X + this.pictureBox_zoom.Width > this.Width)
                    {
                        zoomLocation = new Point(MousePosition.X - this.pictureBox_zoom.Width - 15, MousePosition.Y);
                    }
                }
                this.pictureBox_zoom.Location = zoomLocation;
                if (!this.pictureBox_zoom.Visible)
                {
                    this.pictureBox_zoom.Show();
                }
            }

在“Form1_KeyUp”事件處理函數中添加以下代碼：

為“pictureBox_zoom”添加“Paint”事件處理程序，代碼如下：

<喎?http://www.Bkjia.com/kf/ware/vc/" target="_blank" class="keylink">vcD48cD48L3A+PHByZSBjbGFzcz0="brush:java;"> ///

/// 放大鏡組件重繪事件處理程序 /// 實時顯示鼠標指針位置放大後的圖像 ///

/// /// private void pictureBox_zoom_Paint(object sender, PaintEventArgs e) { Bitmap bmp_lbl = new Bitmap(e.ClipRectangle.Width, e.ClipRectangle.Height); int srcWidth = (int)(this.ZoomBoxWidth / 10); int srcHeight = (int)(this.ZoomBoxHeight / 10); Bitmap bmp = new Bitmap(srcWidth, srcHeight); Rectangle srcRect = new Rectangle(MousePosition.X - 5, MousePosition.Y - 4, srcWidth, srcHeight); if (!isCuting) { srcRect = new Rectangle(MousePosition.X - 6, MousePosition.Y - 5, srcWidth, srcHeight); } Graphics g = Graphics.FromImage(bmp); g.DrawImage(screenImage, 0, 0, srcRect, GraphicsUnit.Pixel); g.Dispose(); //Zoom int x, y; for (int row = 0; row < bmp.Height; row++) { for (int col = 0; col < bmp.Width; col++) { Color pc = bmp.GetPixel(col, row); for (int h = 0; h < 10; h++) { for (int w = 0; w < 10; w++) { x = col * 10 + w; y = row * 10 + h; if (x < bmp_lbl.Width && y < bmp_lbl.Height) { bmp_lbl.SetPixel(x, y, pc); } } } } } e.Graphics.DrawImage(bmp_lbl, 0, 0); int blockX = e.ClipRectangle.Width / 2; int blockY = e.ClipRectangle.Height / 2; SolidBrush brush = new SolidBrush(Color.FromArgb(10, 124, 202)); Pen pen = new Pen(brush, 2.0F); e.Graphics.DrawLine(pen, new Point(0, blockY), new Point(e.ClipRectangle.Width, blockY)); e.Graphics.DrawLine(pen, new Point(blockX, 0), new Point(blockX, e.ClipRectangle.Height)); g.Dispose(); bmp_lbl.Dispose(); }

編譯，運行，截圖看看效果吧！

下一篇：C#軟件開發實例.私人訂制自己的屏幕截圖工具（八）添加鍵盤操作截圖的功能