winform下实现pictureBox全屏播放

最近开发一个项目，需要通过双击pictureBox实现全屏的功能，网上查找资料，加上一点摸索，最终实现了。做一下记录，以备以后需要。

主要功能都在下面这个类里面

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace UAVRadar
{
    /// <summary>  
    /// 定义全屏抽象类  
    /// </summary>  
    public abstract class FullScreenObject
    {
        public abstract void FullScreen(bool flag);
    }
    /// <summary>  
    /// 桌面全屏  
    /// </summary>  
    public unsafe class FullScreenHelper : FullScreenObject
    {
        public bool m_bFullScreen = false;

        WINDOWPLACEMENT m_OldWndPlacement = new WINDOWPLACEMENT();

        Control m_control = null;

        public FullScreenHelper(Control control)
        {
            m_control = control;
        }

        private IntPtr m_OldWndParent = IntPtr.Zero;

        DockStyle old_docker_style;
        int old_left;
        int old_width;
        int old_height;
        int old_top;

        public override void FullScreen(bool flag)
        {
            m_bFullScreen = flag;
            if (!m_bFullScreen)
            {                
                // 取消全屏设置  
                m_control.Dock = old_docker_style;
                m_control.Left = old_left;
                m_control.Top = old_top;
                m_control.Width = old_width;
                m_control.Height = old_height;
                ShellSDK.SetParent(m_control.Handle, m_OldWndParent);
               
            }
            else
            {
               
                // 记录原来的数据  
                old_docker_style = m_control.Dock;
                old_left = m_control.Left;
                old_width = m_control.Width;
                old_height = m_control.Height;
                old_top = m_control.Top;
                m_OldWndParent = ShellSDK.GetParent(m_control.Handle);
                // 设置全屏数据  
                int nScreenWidth = ShellSDK.GetSystemMetrics(0);
                int nScreenHeight = ShellSDK.GetSystemMetrics(1);
                m_control.Dock = DockStyle.None;
                m_control.Left = 0;
                m_control.Top = 0;
                m_control.Width = nScreenWidth;
                m_control.Height = nScreenHeight;
                ShellSDK.SetParent(m_control.Handle, ShellSDK.GetDesktopWindow());
                ShellSDK.SetWindowPos(m_control.Handle, -1, 0, 0, m_control.Right - m_control.Left, m_control.Bottom - m_control.Top, 0);
                
            }
            m_bFullScreen = !m_bFullScreen;
        }

    }

    /// <summary>  
    /// 在容器内部全屏  
    /// </summary>  
    public class FullScreenInContainerHelper : FullScreenObject
    {
        bool m_bFullScreen = false;

        Control m_control = null;

        public FullScreenInContainerHelper(Control control)
        {
            m_control = control;
        }

        private IntPtr m_OldWndParent = IntPtr.Zero;
        private IntPtr m_father_hwnd;
        private RECT m_rect = new RECT();

        public override void FullScreen(bool flag)  
        {  
            m_bFullScreen = flag;  
            if (!m_bFullScreen)  
            {  
                ShellSDK.SetParent(m_control.Handle, m_father_hwnd);  
                ShellSDK.SetWindowPos(m_control.Handle, 0, m_rect.left, m_rect.top, m_rect.right - m_rect.left, m_rect.bottom - m_rect.top, 0);  
                ShellSDK.SetForegroundWindow(m_father_hwnd);  
            }  
            else  
            {  
                m_father_hwnd = ShellSDK.GetParent(m_control.Handle);  
                RECT rect;
                RECT rect_fature;
                ShellSDK.GetWindowRect(m_control.Handle, out rect);  
                POINT pt = new POINT();  
                pt.x = rect.left;  
                pt.y = rect.top;  
                ShellSDK.ScreenToClient(m_father_hwnd, ref pt);  
                rect.right = rect.right - rect.left + pt.x;  
                rect.bottom = rect.bottom - rect.top + pt.y;  
                rect.left = pt.x;  
                rect.top = pt.y;  
                m_rect = rect;  
                ShellSDK.GetWindowRect(m_father_hwnd, out rect_fature);  
                ShellSDK.SetWindowPos(m_control.Handle, 0, 0, 0, rect_fature.right - rect_fature.left, rect_fature.bottom - rect_fature.top, 0);  
            }  
            m_bFullScreen = !m_bFullScreen;  
        }
    }

    /// <summary>  
    /// Windows系统API-SDK  
    /// </summary>  
    public class ShellSDK
    {
        //锁定指定窗口，禁止它更新。同时只能有一个窗口处于锁定状态。锁定指定窗口，禁止它更新。同时只能有一个窗口处于锁定状态  
        [DllImport("User32.dll")]
        public static extern bool LockWindowUpdate(IntPtr hWndLock);

        //函数来设置弹出式窗口，层叠窗口或子窗口的父窗口。新的窗口与窗口必须属于同一应用程序  
        [DllImport("User32.dll")]
        public static extern IntPtr SetParent(IntPtr hWndChild, IntPtr hWndNewParent);

        //函数设置指定窗口的显示状态和恢复，最大化，最小化位置。函数功能： 函及原型     
        [DllImport("User32.dll")]
        public static extern bool SetWindowPlacement(IntPtr hWnd, ref WINDOWPLACEMENT lpwndpl);

        //函数将创建指定窗口的线程设置到前台，并且激活该窗口。键盘输入转向该窗口，并为用户改各种可视的记号  
        [DllImport("User32.dll")]
        public static extern bool SetForegroundWindow(IntPtr hWnd);

        //该函数返回桌面窗口的句柄。桌面窗口覆盖整个屏幕。桌面窗口是一个要在其上绘制所有的图标和其他窗口的区域  
        [DllImport("User32.dll")]
        public static extern IntPtr GetDesktopWindow();

        //函数名。该函数返回指定窗口的显示状态以及被恢复的、最大化的和最小化的窗口位置  
        [DllImport("User32.dll")]
        public static extern bool GetWindowPlacement(IntPtr hWnd, ref WINDOWPLACEMENT lpwndpl);

        //是用于得到被定义的系统数据或者系统配置信息的一个专有名词    
        [DllImport("User32.dll")]
        public static extern int GetSystemMetrics(int nIndex);

        [DllImport("user32.dll", EntryPoint = "GetParent", SetLastError = true)]
        public static extern IntPtr GetParent(IntPtr hWnd);
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern int SetWindowPos(IntPtr hWnd, int hWndInsertAfter, int x, int y, int Width, int Height, int flags);
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        public static extern System.IntPtr GetForegroundWindow();
        [DllImport("user32")]
        public static extern bool GetWindowRect(IntPtr hwnd, out RECT lpRect);
        [DllImport("user32.dll")]
        public static extern uint ScreenToClient(IntPtr hwnd, ref POINT p);
    }

    /// <summary>  
    /// 图像窗口对象  
    /// </summary>  
    public struct WINDOWPLACEMENT
    {
        public uint length;
        public uint flags;
        public uint showCmd;
        public POINT ptMinPosition;
        public POINT ptMaxPosition;
        public RECT rcNormalPosition;
    }
    /// <summary>  
    /// 图像点位位置  
    /// </summary>  
    public struct POINT
    {
        public int x;
        public int y;
    }

    /// <summary>  
    /// 图像区域对象  
    /// </summary>  
    public struct RECT
    {
        public int left;
        public int top;
        public int right;
        public int bottom;
    }
}

然后界面调用就比较简单了，pictureBox控件定义一个DoubleClick事件，然后调用如下代码即可

private FullScreenHelper fullScreenHelper = null;
private void pictureBox2_DoubleClick(object sender, EventArgs e)
        {
            if (fullScreenHelper == null)
            {
                fullScreenHelper = new FullScreenHelper(pictureBox2);
                fullScreenHelper.FullScreen(true);
            }
            else
            {
                fullScreenHelper.FullScreen(false);
                fullScreenHelper = null;
            }
        }