c# winform pictureBox

1：

c# winform pictureBox如何突出显示，放大并给pictureBox边框变色

PictureBox old = null;
        private void pictureBox2_Click(object sender, EventArgs e)
        {
            PictureBox p = (PictureBox)sender;
            if (p == old) return;

            if (old != null)
            {
                old.Width -= 10;
                old.Height -= 10;
                old.Location = new Point(old.Location.X + 5, old.Location.Y + 5);
            }

            old = p;
            p.Width += 10;
            p.Height += 10;
            p.Location = new Point(p.Location.X - 5, p.Location.Y - 5);
            p.BringToFront();
          

        }

        private void pictureBox2_Paint(object sender, PaintEventArgs e)
        {
            PictureBox p = (PictureBox)sender;
            if (p == old)
            {
                Pen pp = new Pen(Color.Red);
                e.Graphics.DrawRectangle(pp, e.ClipRectangle.X, e.ClipRectangle.Y, e.ClipRectangle.X + e.ClipRectangle.Width - 1, e.ClipRectangle.Y + e.ClipRectangle.Height - 1);
            }
        }

转载：http://heisetoufa.iteye.com/blog/227802

2：

/*
 * 主要是对 PictureBox 的操作
 * 截取屏幕图像
 * 获取屏幕指定像素颜色
 * 旋转和翻转图片
 * 虚拟选择框绘制
 * 控件绘图
 *
 * 为了方便，所有步骤在一个方法中完成
 * 创建了一个新的 Form 对象
 * 在该 Form 中添加了一个 PictureBox 对象
*/
// 在 Form_Load 中调用
private void CSDNSample_PictureBoxHandle()
{
    // 复制屏幕，创建原始图片
    Bitmap image = new Bitmap(
        Screen.PrimaryScreen.Bounds.Width,
        Screen.PrimaryScreen.Bounds.Height);
    using (Graphics g = Graphics.FromImage(image))
    {
        g.CopyFromScreen(
            0, 0, 0, 0,
            image.Size,
            CopyPixelOperation.SourceCopy);
        g.Save();
    }
    // 创建 PictureBox 对象
    PictureBox box = new PictureBox();
    box.Location = new Point(0, 0);
    box.SizeMode = PictureBoxSizeMode.StretchImage;
    box.Size = image.Size;
    box.Image = image;
    // 创建 Form 对象
    Form f = new Form();
    f.AutoScroll = true; // 自动滚动
    f.Size = new Size(800, 600);
    // From_FormClosed 用于释放资源
    f.FormClosed += (sender, e) => { image.Dispose(); };
    // From_MouseWheel 用于缩放图片
    // 由于滚动条和缩放同时进行 会有点不爽
    // 建议右键菜单或 Control/Shift/Alt + 鼠标滚轮组合实现
    f.MouseWheel += (sender, e) =>
    {
        if (e.Delta > 0)
        {
            // 限制放大效果 600% 以内
            if (box.Width / image.Width < 6)
            {
                box.Size = new Size(
                    (int)(box.Width * 1.1),
                    (int)(box.Height * 1.1));
            }
        }
        else
        {
            // 限制缩小效果 15% 以内
            if ((float)box.Width / (float)image.Width > 0.15f)
            {
                box.Size = new Size(
                    (int)(box.Width * 0.9),
                    (int)(box.Height * 0.9));
            }
        }
    };
    // 用于记录鼠标按下时的位置
    Point pt = Point.Empty;
    // PictureBox_MouseDown 用于记录鼠标位置 绘制屏幕十字标记
    box.MouseDown += (sender, e) =>
    {
        if (e.Button == MouseButtons.Left)
        {
            pt = e.Location;
            // Cursor.Position 获取全局鼠标位置(屏幕位置)
            // CopyFromScreen 拷贝 1 个屏幕像素并生成图片
            // Bitmap.GetPixel 获取图片上指定像素的颜色
            using (Bitmap bitmap = new Bitmap(1, 1))
            {
                using (Graphics g = Graphics.FromImage(bitmap))
                {
                    g.CopyFromScreen(
                        Cursor.Position.X, Cursor.Position.Y, 0, 0,
                        bitmap.Size, CopyPixelOperation.SourceCopy);
                    g.Save();
                }
                // 设置窗口文本
                // 显示鼠标当前位置和鼠标位置的像素颜色
                Color color = bitmap.GetPixel(0, 0);
                f.Text = string.Format("Pos: {0}, Color: {1}",
                    e.Location, color);
            }
            using (Graphics g = Graphics.FromHwnd(box.Handle))
            {
                using (Pen p = new Pen(Color.IndianRed, 3))
                {
                    g.DrawLine( // 画十字图形的 X 轴
                        p, new Point(e.X - 10, e.Y), new Point(e.X + 10, e.Y));
                    g.DrawLine( // 画十字图形的 Y 轴
                        p, new Point(e.X, e.Y - 10), new Point(e.X, e.Y + 10));
                }
            }
        }
    };
    // PictureBox_MouseUp 用于清除鼠标位置信息和屏幕十字标记
    box.MouseUp += (sender, e) =>
    {
        if (e.Button == MouseButtons.Left)
        {
            pt = Point.Empty;
            box.Refresh();
        }
    };
    // PictureBox_MouseMove 用于绘制选择框
    box.MouseMove += (sender, e) =>
    {
        // 设置窗口文本 显示鼠标当前位置
        f.Text = string.Format("Pos: {0}", e.Location);
        if (e.Button == MouseButtons.Left && pt != Point.Empty)
        {
            using (Graphics g = Graphics.FromHwnd(box.Handle))
            {
                using (Pen p = new Pen(Color.IndianRed, 1))
                {
                    // pt1 用于判断鼠标是否离开了 PictureBox
                    // 如果离开则重设 pt1
                    // 如此可保证被绘制的矩形一定出现在 PictureBox 中
                    Point pt1 = e.Location;
                    if (pt1.X < 0) pt1.X = 0;
                    if (pt1.Y < 0) pt1.Y = 0;
                    if (pt1.X > box.Width - 1) pt1.X = box.Width - 1;
                    if (pt1.Y > box.Height - 1) pt1.Y = box.Height - 1;
                    box.Refresh(); // 不刷新的话 会出现N个矩形
                    p.DashStyle = System.Drawing.Drawing2D.DashStyle.Dash;
                    g.DrawPolygon(p, new Point[] {
                        pt,
                        new Point (pt1.X, pt.Y),
                        pt1,
                        new Point(pt.X, pt1.Y) });
                }
            }
        }
    };
    // 记录当前翻转样式
    int rotate = 0;
    // PictureBox_MouseDoubleClick 用于翻转图片
    box.MouseDoubleClick += (sender, e) =>
    {
        if (e.Button == MouseButtons.Left)
        {
            // 由于是对 PictureBox 进行的操作
            // 图片只是进行了翻转，但大小未变
            // 所以需要通过图片的某个边判断
            // 图片是否因翻转而导致 Width / Height 互换
            int imgWidth = box.Image.Width;
            box.Image.RotateFlip((RotateFlipType)rotate);
            if (++rotate > 7) rotate = 0;
            if (imgWidth == box.Image.Width) return;
            box.Size = new Size(box.Height, box.Width);
        }
    };
    f.Controls.Add(box);
    f.Show();
}

转载：http://blog.csdn.net/qqamoon/article/details/6079697