最近由于工程需要开始研发基于Windows的自动录屏软件，很多细节很多功能需要处理，毕竟一个完美的录屏软件不是你随随便便就可以写出来的。首先参考了大部分的录屏软件，在研发的过程中遇到了很多的问题；比如-视频加载、麦克风加载、麦克风音量调节、视频播放进度控、视频音量控制、等等很多细节部分都需要好好规划才能开始做。录屏采用的是视频帧的思维逻辑进行编写的。
目前已经基本上成型，基于WPF采用了Model - View框架进行动态加载，每个线程与线程之间采用Async异步执行，并使用线程等待；录屏基本功能包含了（展示历史录屏记录、删除、录屏、视频编码、视频播放及删除、麦克风调用（音量调节-跟随系统）、加载视频（拖拉-旋转）、系统遮罩 等）；编码的核心是采用FFMPEG（这个工具真的非常强大）;
这边提供几个核心代码仅供参考：
1-难点：系统遮罩核心方法（使用Windows API）:
1 /// <summary>
2 /// 视图模型属性改变
3 /// </summary>
4 /// <param name="sender">
5 /// The sender.
6 /// </param>
7 /// <param name="propertyChangedEventArgs">
8 /// 属性改变事件参数
9 /// </param>
10 private void ViewModelOnPropertyChanged(object sender, PropertyChangedEventArgs propertyChangedEventArgs)
11 {
12 if (propertyChangedEventArgs.PropertyName == "IsRecording")
13 {
14 this.Locked = this.ViewModel.IsRecording;
15 if (this.ViewModel.IsRecording)
16 {
17 var hwnd = new WindowInteropHelper(this).Handle;
18 NativeWindowHelper.SetWindowExTransparent(hwnd);
19 }
20 }
21
22 if (propertyChangedEventArgs.PropertyName == "IsFullScreen")
23 {
24 this.IsFullScreen = this.ViewModel.IsFullScreen;
25 }
26 }
改变属性的时候触发
1 #region Constants
2
3 /// <summary>
4 /// The gw l_ exstyle.
5 /// </summary>
6 [SuppressMessage("StyleCop.CSharp.NamingRules", "SA1310:FieldNamesMustNotContainUnderscore",
7 Justification = "Reviewed. Suppression is OK here.")]
8 private const int GWL_EXSTYLE = -20;
9
10 /// <summary>
11 /// The w s_ e x_ transparent.
12 /// </summary>
13 [SuppressMessage("StyleCop.CSharp.NamingRules", "SA1310:FieldNamesMustNotContainUnderscore",
14 Justification = "Reviewed. Suppression is OK here.")]
15 private const int WS_EX_TRANSPARENT = 0x00000020;
16
17
18
19
20 #endregion
21
22 #region Public Methods and Operators
23
24 /// <summary>
25 /// 窗口前置透明设置命令
26 /// </summary>
27 /// <param name="hwnd">
28 /// The hwnd.
29 /// </param>
30 public static void SetWindowExTransparent(IntPtr hwnd)
31 {
32 var extendedStyle = GetWindowLong(hwnd, GWL_EXSTYLE);
33 SetWindowLong(hwnd, GWL_EXSTYLE, extendedStyle | WS_EX_TRANSPARENT);
34 }
35
36 #endregion
37
38 #region Methods
39
40 /// <summary>
41 /// The get window long.
42 /// </summary>
43 /// <param name="hwnd">
44 /// The hwnd.
45 /// </param>
46 /// <param name="index">
47 /// The index.
48 /// </param>
49 /// <returns>
50 /// The <see cref="int"/>.
51 /// </returns>
52 [DllImport("user32.dll")]
53 private static extern int GetWindowLong(IntPtr hwnd, int index);
54
55 /// <summary>
56 /// The set window long.
57 /// </summary>
58 /// <param name="hwnd">
59 /// The hwnd.
60 /// </param>
61 /// <param name="index">
62 /// The index.
63 /// </param>
64 /// <param name="newStyle">
65 /// The new style.
66 /// </param>
67 /// <returns>
68 /// The <see cref="int"/>.
69 /// </returns>
70 [DllImport("user32.dll")]
71 private static extern int SetWindowLong(IntPtr hwnd, int index, int newStyle);
72
73 #endregion
API方法
2-难点：麦克风获取及控制
<Slider x:Name="volumeSlider" Grid.Column="7" Grid.ColumnSpan="3" Grid.Row="1" Width="100" Height="20" Minimum="0" Maximum="100" Value="100" VerticalAlignment="Center" />
1 //定义一个获取之前拉动时候的value值，然后跟当前的value对比，选择触发
2 private bool isUserChangeVolume = true;
3 private VolumeControl volumeControl;
4 //private DispatcherTimer volumeControlTimer;
5
6 /// <summary>
7 /// 加载拖动条的事件
8 /// </summary>
9 /// <param name="sender"></param>
10 /// <param name="e"></param>
11 private void volumeSlider_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
12 {
13 if (isUserChangeVolume)
14 {
15 volumeControl.MasterVolume = volumeSlider.Value;
16 }
17 }
18
19 private void InitializeAudioControl()
20 {
21 volumeControl = VolumeControl.Instance;
22 volumeControl.OnAudioNotification += volumeControl_OnAudioNotification;
23 volumeControl_OnAudioNotification(null, new AudioNotificationEventArgs() { MasterVolume = volumeControl.MasterVolume });
24
25 //volumeControlTimer = new DispatcherTimer();
26 //volumeControlTimer.Interval = TimeSpan.FromTicks(150);
27 //volumeControlTimer.Tick += volumeControlTimer_Tick;
28 }
29
30 void volumeControl_OnAudioNotification(object sender, AudioNotificationEventArgs e)
31 {
32 this.isUserChangeVolume = false;
33 try
34 {
35 this.Dispatcher.Invoke(new Action(() => { volumeSlider.Value = e.MasterVolume; }));
36 }
37 catch { }
38 this.isUserChangeVolume = true;
39 }
40
41 void volumeControlTimer_Tick(object sender, EventArgs e)
42 {
43 //获取系统主声道、左声道、右声道音量值
44 //double[] information = volumeControl.AudioMeterInformation;
45 //mMasterPBar.Value = information[0];
46 //mLeftPBar.Value = information[1];
47 //mRightPBar.Value = information[2];
48 }
3-难点：系统遮罩（其实也不能算难点，这个是API调用的时候颜色控制）;
4-难点：视频旋转核心代码
1 /// <summary>
2 /// 旋转视频
3 /// </summary>
4 /// <param name="sender"></param>
5 /// <param name="e"></param>
6 private void RotateCamera_bt(object sender, RoutedEventArgs e)
7 {
8 if (AnAngle > 360 || AnAngle == 0)
9 {
10 AnAngle = 90;
11 }
12 TransformGroup transformGroup = new TransformGroup();
13
14 ScaleTransform scaleTransform = new ScaleTransform();
15 scaleTransform.ScaleX = -1;
16 transformGroup.Children.Add(scaleTransform);
17
18 RotateTransform rotateTransform = new RotateTransform(AnAngle);
19 transformGroup.Children.Add(rotateTransform);
20 videoPlayer.RenderTransform = transformGroup;
21 AnAngle += 90;
22 }
旋转视频代码
5-难点：录屏核心代码（这部分代码视频格式可以自行调整，颜色代码原理已经理解。）
1 /// <summary>
2 /// Starts the recording.
3 /// </summary>
4 public void StartRecording()
5 {
6 this.notifyIcon.HideBalloonTip();
7 this.IsRecording = true;
8
9
10 var fileName = string.Format("Recording {0}.mp4", DateTime.Now.ToString("yy-MM-dd HH-mm-ss"));
11 var outputFilePath = Path.Combine(this.settings.StoragePath, fileName);
12 this.fileViewModel = new ScreenGunFileViewModel(outputFilePath, RecordingStage.DoingNothing);
13
14 var opts = new ScreenRecorderOptions(this.RecordingRegion)
15 {
16 DeleteMaterialWhenDone = true,
17 OutputFilePath = outputFilePath,
18 RecordMicrophone = this.UseMicrophone,
19 AudioRecordingDeviceNumber = this.settings.RecordingDeviceNumber
20 };
21
22 var progress = new Progress<RecorderState>(state => this.fileViewModel.RecordingStage = state.Stage);
23 this.recorder.Start(opts, progress);
24 }
录屏代码
6-难点：屏幕画框代码(采集X,Y坐标及遮幕的宽,高)
1 /// <summary>
2 /// 设置初始区域
3 /// </summary>
4 private void SetupInitialRegion()
5 {
6 var cursorPos = System.Windows.Forms.Cursor.Position;
7 foreach (var screen in Screen.AllScreens)
8 {
9 if (screen.Bounds.Contains(cursorPos) == false)
10 {
11 continue;
12 }
13
14 var regionWidth = (double)screen.Bounds.Width / 2;
15 var regionHeight = (double)screen.Bounds.Height / 2;
16 double x = ((double)screen.Bounds.Width / 2) - (regionWidth / 2);
17 double y = ((double)screen.Bounds.Height / 2) - (regionHeight / 2);
18 x -= this.virtualScreen.X - screen.Bounds.X;
19 y -= this.virtualScreen.Y - screen.Bounds.Y;
20
21 this.startPosition = new Point(x, y);
22 this.endPosition = new Point(x + regionWidth, y + regionHeight);
23 this.UpdatePosition();
24 break;
25 }
26 }
以上是这几天研究的成果，目前还在进一步研究中，效果图如下：
时间： 2024-10-23 01:24:27