C#窗体程序实现全屏及取消全屏步骤

由于项目需要，需要用vs窗体程序实现播放视频的窗口的全屏和取消全屏。

具体实现界面如图：

这是初始状态，视频框的右上角就是控制全屏的按钮

这是全屏后的状态，此时全屏按钮变成了取消全屏的样式

注：为了界面的美观我的全屏并没有把左边的那些控件也盖住，但是是可以设置的，下边代码部分我会进行讲解。

1、首先说明一下我所用的控件及我的项目中控件的名称，以便大家理解。

显示视频的黑框是一个picturebox即代码中的VideoPlayWnd，全屏/取消全屏是一个button即代码中的button4

2、具体代码如下：

全屏和取消全屏是一个按钮即button4

private Int16 zoom = -1;//用来控制点击此button4的时候，是需要全屏还是取消全屏
//视频窗口的缩放代码
 private void button4_Click(object sender, EventArgs e)
 {
  if(zoom<0)
  {
   float w = this.Width - 210; //为了保证左边的控件不被挡上减了一个210
   float h = this.Height - 50;//为了底下的按钮不被挡上，因为还要用到，因此减了50
   this.VideoPlayWnd.Size = Size.Ceiling(new SizeF(w, h));//重新部署视频框即这个picturebox空间的长宽
   VideoPlayWnd.Location = new System.Drawing.Point(210, 0);//视频框的左上角坐标，会发现与我上边减去的210一致（大家肯定都理解为什么我就不说了）
   button4.Location = new System.Drawing.Point(795, 0);//不能只有picturebox变了，这个button的位置也要保证和视频框同步，所以需要重设坐标
   // button4.BackgroundImage = Image.FromFile(@"E:\lwj\addpersoninfo\addpersoninfo\Resources\退出全屏.png");//绝对路径（这是我测试的时候用的）
   button4.BackgroundImage = Image.FromFile(AppDomain.CurrentDomain.BaseDirectory + @"退出全屏.png");//AppDomain.CurrentDomain.BaseDirectory语句可以获取到你当前项目的bin目录，所以需要把图片放到对应目录下
   zoom = 1;//全屏之后，再点击需要取消全屏，因此要改变zoom的值
  }
  else
  { //以下为取消全屏，即还原自己的视频框和按钮，具体操作类似全屏，就不细致注释了
   VideoPlayWnd.Location = new System.Drawing.Point(495, 360);
   this.VideoPlayWnd.Size = Size.Ceiling(new SizeF(323, 271));
   button4.Location = new System.Drawing.Point(795, 360);
   button4.BackgroundImage = Image.FromFile(AppDomain.CurrentDomain.BaseDirectory + @"全屏.png");
   zoom = -1;//取消全屏后再点击就要进行全屏，因此继续设为-1（保证小于0，以满足全屏操作的if条件）
  }
 }

以上代码中的按钮是给它加了一个全屏样式的背景图片，并在点击时切换背景图片。

补充知识：C# 窗体视频控件进入全屏模式和退出全屏模式

窗体控件进入全屏模式和退出全屏模式，视频播放的时候用到此功能。

工具类代码

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 CvNetVideo.Play
{
class FullScreenHelper
{
 bool m_bFullScreen = false;
 IntPtr m_OldWndParent = IntPtr.Zero;
 WINDOWPLACEMENT m_OldWndPlacement = new WINDOWPLACEMENT();
 Control m_control = null;

public FullScreenHelper(Control c)
 {
  m_control = c;
 }
 struct POINT
 {
  int x;
  int y;
 };
 struct RECT
 {
  public int left;
  public int top;
  public int right;
  public int bottom;
 };
 //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);
  public void FullScreen(bool flag)
 {
  m_bFullScreen = flag;
  if (!m_bFullScreen)
  {
   LockWindowUpdate(m_control.Handle);
   SetParent(m_control.Handle, m_OldWndParent);
   SetWindowPlacement(m_control.Handle, ref m_OldWndPlacement);
   SetForegroundWindow(m_OldWndParent);
   LockWindowUpdate(IntPtr.Zero);
  }
  else
  {
   GetWindowPlacement(m_control.Handle, ref m_OldWndPlacement);
   int nScreenWidth = GetSystemMetrics(0);
   int nScreenHeight = GetSystemMetrics(1);
   m_OldWndParent = GetParent(m_control.Parent.Handle);
   SetParent(m_control.Handle, GetDesktopWindow());
   WINDOWPLACEMENT wp1 = new WINDOWPLACEMENT();
   wp1.length = (uint)Marshal.SizeOf(wp1);
   wp1.showCmd = 1;
   wp1.rcNormalPosition.left = 0;
   wp1.rcNormalPosition.top = 0;
   wp1.rcNormalPosition.right = nScreenWidth;
   wp1.rcNormalPosition.bottom = nScreenHeight;
   SetWindowPlacement(m_control.Handle, ref wp1);
   SetForegroundWindow(GetDesktopWindow());
   SetForegroundWindow(m_control.Handle);
  }
  m_bFullScreen = !m_bFullScreen;
 }
 struct WINDOWPLACEMENT
 {
  public uint length;
  public uint flags;
  public uint showCmd;
  public POINT ptMinPosition;
  public POINT ptMaxPosition;
  public RECT rcNormalPosition;
 };
}
}

调用方式

/// <summary>
 /// 全屏事件
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 private void UCVideo_DoubleClick(object sender, EventArgs e)
 {
  //全屏设置
  //sdlVideo.SDL_MaximizeWindow();
  fullScreenHelper = new CvNetVideo.Play.FullScreenHelper(this);
  fullScreenHelper.FullScreen(true);
  Console.WriteLine("Entrance FullScreen Mode");
 }
 /// <summary>
 /// 按键弹起事件
 /// </summary>
 private void UCVideo_KeyUp(object sender, KeyEventArgs e)
 {
  // ESC 退出全屏
  if (e.KeyCode == Keys.Escape&& fullScreenHelper!=null)
  {
   fullScreenHelper.FullScreen(false);
   fullScreenHelper = null;
   Console.WriteLine("Exit FullScreen Mode");
  }  
 }

测试效果图

注意：在使用SDL的全屏操作过程中设置是无效的，播放视频过程中不能实现修改。代码如下：

public void SDL_MaximizeWindow()
 {
  Console.WriteLine("设置全屏");

SDL.SDL_MaximizeWindow(screen);
  SDL.SDL_SetWindowFullscreen(screen, SDL.SDL_GetWindowFlags(screen));
  SDL.SDL_ShowWindow(screen);

//int width, height;
   获取最大窗口值
  //SDL2.SDL.SDL_GetWindowMaximumSize(screen, out width, out height);
   设置最大窗口值
  //if (width>0&&height>0)
  //{
  // SDL2.SDL.SDL_SetWindowMaximumSize(screen, width, height);
  // Console.WriteLine("设置全屏......成功!width=" + width + ",height=" + height);
  //}
  //else
  //{
  // Console.WriteLine("设置全屏......失败!width=" + width + ",height=" + height);
  // SDL2.SDL.SDL_SetWindowMaximumSize(screen, w, h);
  //}
 }

工具代码功能改进

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 CvNetVideo.Play
{
/// <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
{
 bool m_bFullScreen = false;

WINDOWPLACEMENT m_OldWndPlacement = new WINDOWPLACEMENT();

UCVideo m_control = null;

public FullScreenHelper(UCVideo 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)
  {
   #region 方式一：窗体容积改变时不能全屏，未能解决IE全屏显示不全问题
   //ShellSDK.LockWindowUpdate(m_control.Handle);
   //ShellSDK.SetParent(m_control.Handle, m_OldWndParent);
   //ShellSDK.SetWindowPlacement(m_control.Handle, ref m_OldWndPlacement);
   //ShellSDK.SetForegroundWindow(m_OldWndParent);
   //ShellSDK.LockWindowUpdate(IntPtr.Zero);
   #endregion

#region 方式二：在容器改变时可以实现全屏，未能解决IE全屏显示不全问题
   // 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);
   #endregion
  }
  else
  {
   #region 方式一：窗体容积改变时不能全屏，未能解决IE全屏显示不全问题
   //ShellSDK.GetWindowPlacement(m_control.Handle, ref m_OldWndPlacement);
   //int nScreenWidth = ShellSDK.GetSystemMetrics(0);
   //int nScreenHeight = ShellSDK.GetSystemMetrics(1);
   //m_OldWndParent = ShellSDK.GetParent(m_control.Handle);
   //ShellSDK.SetParent(m_control.Handle, ShellSDK.GetDesktopWindow());
   //WINDOWPLACEMENT wp1 = new WINDOWPLACEMENT();
   //wp1.length = (uint)Marshal.SizeOf(wp1);
   //wp1.showCmd = 1;
   //wp1.rcNormalPosition.left = 0;
   //wp1.rcNormalPosition.top = 0;
   //wp1.rcNormalPosition.right = Screen.PrimaryScreen.Bounds.Width/*nScreenWidth*/;
   //wp1.rcNormalPosition.bottom = Screen.PrimaryScreen.WorkingArea.Height/* nScreenHeight*/;
   //ShellSDK.SetWindowPlacement(m_control.Handle, ref wp1);
   //ShellSDK.SetForegroundWindow(ShellSDK.GetDesktopWindow());
   //ShellSDK.SetForegroundWindow(m_control.Handle);
   #endregion

#region 方式二：在容器改变时可以实现全屏，未能解决IE全屏显示不全问题
   // 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);
   #endregion
  }
  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);
   ShellSDK.GetWindowRect(m_control.Handle, out RECT 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 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>
/// 图像区域对象
/// </summary>
public struct RECT
{
 public int left;
 public int top;
 public int right;
 public int bottom;
}

/// <summary>
/// 图像点位位置
/// </summary>
public struct POINT
{
 public int x;
 public int y;
}

/// <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;
}
}

来源：https://blog.csdn.net/weixin_39638351/article/details/81512795