这篇文章将讲述实现WPF的UI和WCF中的双工通信。实现文字部分的聊天功能和实现共享白板的功能。

画WPF的界面其实是一件麻烦的事情。虽然WPF和WindowsForm一样，能将控件拖到哪，它就在哪。我们在开发asp.net项目的时候用从原始的table布局，到现在流行的div+css布局。这些都需要设计人员的仔细设计。这个程序的布局我采用Grid和StackPanel两种方式。Gird类似html的表格布局，StackPanel就就像它的字面意思“堆栈面板”。

WPF的UI实现

首先新建一个wpf的应用程序，改名为ZqlChart。添加一个UserControl，用来实现登陆窗体，这个是用了StackPanel进行布局。XAML代码如下：

<UserControl x:Class="ZqlChart.LoginControl"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"Height="210" Width="350" Loaded="UserControl_Loaded"><StackPanel><Border Height="220" BorderBrush="#FFFFFFFF" BorderThickness="2,2,2,0" CornerRadius="5,5,0,0"><Border.Background><LinearGradientBrush EndPoint="0.713,0.698" StartPoint="0.713,-0.139"><GradientStop Color="#FFFFFFFF" Offset="0.933"/><GradientStop Color="LightBlue" Offset="0.337"/></LinearGradientBrush></Border.Background><StackPanel Name="infoPanel" Orientation="Vertical" Margin="10,10,10,10"><StackPanel Name="typePanel" Orientation="Horizontal"><RadioButton Name="chatTypeServer" FontSize="24" Margin="80,0,20,0" Checked="chatTypeServer_Checked" VerticalContentAlignment="Center">服务端</RadioButton><RadioButton Name="chatTypeClient" FontSize="24" Checked="chatTypeClient_Checked" VerticalContentAlignment="Center">客户端</RadioButton></StackPanel><StackPanel Name="serverPanel" Orientation="Horizontal" Margin="0,10,0,0"><Label Name="lblServer" FontSize="20" Width="120" HorizontalContentAlignment="Right" VerticalContentAlignment="Center">服务端:</Label><TextBox Height="30" Name="txtServer" Width="160" FontSize="20" VerticalContentAlignment="Center" /></StackPanel><StackPanel Name="usernamePanel" Orientation="Horizontal" Margin="0,10,0,10"><Label Name="lblUserName" FontSize="20" Width="120" HorizontalContentAlignment="Right">用户名:</Label><TextBox Height="30" Name="txtUserName" Width="160" FontSize="20" VerticalContentAlignment="Center" /></StackPanel><StackPanel Name="buttonPanel" Orientation="Horizontal" HorizontalAlignment="Center" VerticalAlignment="Center"><Button Name="btnLogin" Width="120" FontSize="20" Margin="10,10,10,10" Click="btnLogin_Click">连接</Button><Button Name="btnCancel" Width="120" FontSize="20" Margin="10,10,10,10" Click="btnCancel_Click">取消</Button></StackPanel></StackPanel></Border></StackPanel>
</UserControl>

界面效果如下：

聊天的主界面，如下图：

大框架是3行3列。XAML代码如下：

<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"x:Name="ZqlChartMainWindow"x:Class="ZqlChart.ZqlChartWindow" Title="麒麟语音聊天室” Height="600" Width="800"Background="#FF3B3737" Loaded="Window_Loaded" MinWidth="800" MinHeight="500"><Grid x:Name="LayoutRoot" ><Grid.RowDefinitions><RowDefinition Height="50" /><RowDefinition Height="261" /><RowDefinition Height="250" /></Grid.RowDefinitions><Grid.ColumnDefinitions><ColumnDefinition Width="150" /><ColumnDefinition Width="580*" /><ColumnDefinition Width="48" /></Grid.ColumnDefinitions><Border Name="BorderUsersList" Grid.Column="0" Grid.Row="1" Grid.RowSpan="2" CornerRadius="8,8,8,8" Background="LightBlue" BorderThickness="0,0,4,4" ><ListView Name="lvUsers" Margin="10" FontSize="20"><ListView.BitmapEffect><DropShadowBitmapEffect /></ListView.BitmapEffect></ListView></Border><Border Name="BorderEditingType" Grid.ColumnSpan="3" CornerRadius="8,8,8,8" Background="LightBlue" BorderThickness="0,4,4,4"><StackPanel Orientation="Horizontal" VerticalAlignment="Center"><Button Margin="0,0,0,0"  Height="28" Width="121" Click="Button_Click" Background="White">与其语音聊天

                </Button><RadioButton Name="rbInk" Content="墨水" Margin="15,0,0,0" VerticalAlignment="Center" FontSize="20" IsChecked="True" Tag="{x:Static InkCanvasEditingMode.Ink}" Click="rbInkType_Checked"></RadioButton><RadioButton Name="rbEraserByStroke" Content="一笔一笔清除" Margin="15,0,0,0" VerticalAlignment="Center" FontSize="20" Tag="{x:Static InkCanvasEditingMode.EraseByStroke}" Click="rbInkType_Checked"></RadioButton><RadioButton Name="rbEraserByPoint" Content="一点一点清除" Margin="15,0,0,0" VerticalAlignment="Center" FontSize="20" Tag="{x:Static InkCanvasEditingMode.EraseByPoint}" Click="rbInkType_Checked"></RadioButton><TextBlock Margin="25,0,10,0" VerticalAlignment="Center" FontSize="20" >选择颜色:</TextBlock><Button Margin="0,0,0,0" Background="White" Height="28" Width="64" Click="OnSetFill"><Rectangle Width="54" Height="20" Stroke="Black" StrokeThickness="2"><Rectangle.Fill><SolidColorBrush Color="{Binding ElementName=ZqlChartMainWindow, Path=FillColor}" /></Rectangle.Fill></Rectangle></Button></StackPanel></Border><Border Name="BorderInkCanvas" Grid.Column="1" Grid.Row="1" Background="LightBlue" BorderThickness="4,4,4,4" CornerRadius="8,8,8,8" Grid.ColumnSpan="2"><InkCanvas x:Name="inkCanv" Margin="10" Background="White" StrokeCollected="inkCanv_StrokeCollected" StrokeErasing="inkCanv_StrokeErasing" StrokeErased="inkCanv_StrokeErased" VerticalAlignment="Top" ></InkCanvas></Border><Border Name="BorderInkMessage" Grid.Column="1" Grid.Row="2" Background="LightBlue" BorderThickness="0,0,4,4" CornerRadius="8,8,8,8" Grid.ColumnSpan="2"><Grid ><Grid.RowDefinitions><RowDefinition /><RowDefinition  Height="30" /></Grid.RowDefinitions><Grid.ColumnDefinitions><ColumnDefinition Width="500*" /><ColumnDefinition Width="62*" /><ColumnDefinition Width="62*" /></Grid.ColumnDefinitions><Border  Grid.Column="1" Grid.Row="1" Background="LightBlue" BorderThickness="4,4,4,4" CornerRadius="8,8,8,8" ><Button Content="发送"  Height="23"  Name="btnSend"  Click="btnSend_Click" /></Border><Border  Grid.ColumnSpan="3" Background="LightBlue" BorderThickness="4,4,4,4" CornerRadius="8,8,8,8" ><TextBox   Name="txtAllMessage" ><TextBox.BitmapEffect><DropShadowBitmapEffect /></TextBox.BitmapEffect></TextBox></Border><Border  Grid.Row="1" Background="LightBlue" BorderThickness="4,4,4,4" CornerRadius="8,8,8,8" ><TextBox Grid.Row="1" Name="txtMessage" /></Border><Border  Grid.Column="2" Grid.Row="1"  Background="LightBlue" BorderThickness="4,4,4,4" CornerRadius="8,8,8,8" ><Button  Content="关闭" Name="btnLeave"  Height="23" FontSize="10" Click="btnLeave_Click"></Button></Border></Grid></Border><Canvas Name="loginCanvas" Grid.Column="1" Grid.Row="1" Width="500" Height="300" VerticalAlignment="Top" HorizontalAlignment="Center" Margin="39,78,41,0" Grid.RowSpan="2" /></Grid>
</Window>窗体就设计好了。

WCF双工通信：

双工通信能允许服务通知用户当前的进度情况。我们可以通过使用指定CallbackContract的ServiceContract属性的服务使用双工，如服务器端的代码如下：

[ServiceContract(CallbackContract = typeof(IService1Callback))]
public interface IService1
{[OperationContract]string GetData(int value);
}[ServiceContract]
public interface IService1Callback
{[OperationContract]void Reply(string message);
}

客户端代码：

class Program
{static void Main(string[] args){var callback = new Service1Callback();var proxy = new Service1Client(new InstanceContext(callback));Console.WriteLine(proxy.GetData(42));Console.ReadLine();}
}class Service1Callback : IService1Callback
{public void Reply(string message){Console.WriteLine(message);}
}

这篇文章中我将利用WCF的双工通信实现文字聊天的功能和共享白板的功能。

定义协议：

    public interface IZqlChartService{[OperationContract()]bool Join(ChatUser chatUser);[OperationContract()]void Leave(ChatUser chatUser);[OperationContract]void SendBroadcastMessage(string strUserName, string message);[OperationContract()]bool IsUserNameTaken(string strUserName);[OperationContract()]void SendInkStrokes(MemoryStream memoryStream);}

定义回调：

    public interface IZqlChartServiceCallback{[OperationContract(IsOneWay = true)]void NotifyMessage(string message);[OperationContract(IsOneWay = true)]void UpdateUsersList(List<ChatUser> listChatUsers);[OperationContract(IsOneWay = true)]void OnInkStrokesUpdate(ChatUser chatUser, byte[] bytesStroke);[OperationContract(IsOneWay = true)]void ServerDisconnected();}

实现服务：

    public class ZqlChartService : IZqlChartService{public static Dictionary<IZqlChartServiceCallback, ChatUser> s_dictCallbackToUser = new Dictionary<IZqlChartServiceCallback, ChatUser>();public ZqlChartService(){}public bool Join(ChatUser chatUser){IZqlChartServiceCallback client = OperationContext.Current.GetCallbackChannel<IZqlChartServiceCallback>();if (s_dictCallbackToUser.ContainsValue(chatUser) == false){s_dictCallbackToUser.Add(client, chatUser);}foreach (IZqlChartServiceCallback callbackClient in s_dictCallbackToUser.Keys){callbackClient.UpdateUsersList(s_dictCallbackToUser.Values.ToList());}return true;}public void Leave(ChatUser chatUser){IZqlChartServiceCallback client = OperationContext.Current.GetCallbackChannel<IZqlChartServiceCallback>();if (s_dictCallbackToUser.ContainsKey(client)){s_dictCallbackToUser.Remove(client);}foreach (IZqlChartServiceCallback callbackClient in s_dictCallbackToUser.Keys){if (chatUser.IsServer){if (callbackClient != client){//server user logout, disconnect clientscallbackClient.ServerDisconnected();}}else{//normal user logoutcallbackClient.UpdateUsersList(s_dictCallbackToUser.Values.ToList());}}if (chatUser.IsServer){s_dictCallbackToUser.Clear();}}public bool IsUserNameTaken(string strNickName){foreach (ChatUser chatUser in s_dictCallbackToUser.Values){if (chatUser.NickName.ToUpper().CompareTo(strNickName) == 0){return true;}}return false;}public void SendInkStrokes(MemoryStream memoryStream){IZqlChartServiceCallback client = OperationContext.Current.GetCallbackChannel<IZqlChartServiceCallback>();foreach (IZqlChartServiceCallback callbackClient in s_dictCallbackToUser.Keys){if (callbackClient != OperationContext.Current.GetCallbackChannel<IZqlChartServiceCallback>()){callbackClient.OnInkStrokesUpdate(s_dictCallbackToUser[client], memoryStream.GetBuffer());}}}public void SendBroadcastMessage(string clientName, string message){IZqlChartServiceCallback client =OperationContext.Current.GetCallbackChannel<IZqlChartServiceCallback>();if (client != null){foreach (IZqlChartServiceCallback callbackClient in s_dictCallbackToUser.Keys){if (callbackClient != OperationContext.Current.GetCallbackChannel<IZqlChartServiceCallback>()){callbackClient.NotifyMessage(clientName + ": " + message);}}}}}

客户端：

    [System.Diagnostics.DebuggerStepThroughAttribute()][System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "3.0.0.0")]public partial class ZqlChartServiceClient : System.ServiceModel.DuplexClientBase<IZqlChartService>, IZqlChartService{public ZqlChartServiceClient(System.ServiceModel.InstanceContext callbackInstance) :base(callbackInstance){}public ZqlChartServiceClient(System.ServiceModel.InstanceContext callbackInstance, string endpointConfigurationName) :base(callbackInstance, endpointConfigurationName){}public ZqlChartServiceClient(System.ServiceModel.InstanceContext callbackInstance, string endpointConfigurationName, string remoteAddress) :base(callbackInstance, endpointConfigurationName, remoteAddress){}public ZqlChartServiceClient(System.ServiceModel.InstanceContext callbackInstance, string endpointConfigurationName, System.ServiceModel.EndpointAddress remoteAddress) :base(callbackInstance, endpointConfigurationName, remoteAddress){}public ZqlChartServiceClient(System.ServiceModel.InstanceContext callbackInstance, System.ServiceModel.Channels.Binding binding, System.ServiceModel.EndpointAddress remoteAddress) :base(callbackInstance, binding, remoteAddress){}public bool Join(ZqlChartObjects.ChatUser chatUser){return base.Channel.Join(chatUser);}public void Leave(ZqlChartObjects.ChatUser chatUser){base.Channel.Leave(chatUser);}public bool IsUserNameTaken(string strUserName){return base.Channel.IsUserNameTaken(strUserName);}public void SendInkStrokes(System.IO.MemoryStream memoryStream){base.Channel.SendInkStrokes(memoryStream);}public void SendBroadcastMessage(string strUserName, string message){base.Channel.SendBroadcastMessage(strUserName, message);}}

客户端回调类：

    public class ClientCallBack : IZqlChartServiceCallback{public static ClientCallBack Instance;private SynchronizationContext m_uiSyncContext = null;private ZqlChartWindow m_mainWindow;//ActiveCallWindow _activeCallForm;//CallManager _callManager;public ClientCallBack(SynchronizationContext uiSyncContext, ZqlChartWindow mainWindow){m_uiSyncContext = uiSyncContext;m_mainWindow = mainWindow;}public void OnInkStrokesUpdate(ZqlChartObjects.ChatUser chatUser, byte[] bytesStroke){SendOrPostCallback callback =delegate(object state){m_mainWindow.OnInkStrokesUpdate(state as byte[] );};m_uiSyncContext.Post(callback, bytesStroke);SendOrPostCallback callback2 =delegate(object objchatUser){m_mainWindow.LastUserDraw(objchatUser as ZqlChartObjects.ChatUser);};m_uiSyncContext.Post(callback2, chatUser);}public void UpdateUsersList(List<ZqlChartObjects.ChatUser> listChatUsers){SendOrPostCallback callback =delegate(object objListChatUsers){m_mainWindow.UpdateUsersList(objListChatUsers as List<ZqlChartObjects.ChatUser>);};m_uiSyncContext.Post(callback, listChatUsers);}public void ServerDisconnected(){SendOrPostCallback callback =delegate(object dummy){m_mainWindow.ServerDisconnected();};m_uiSyncContext.Post(callback, null);}public void NotifyMessage(string message){SendOrPostCallback callback =delegate(object dummy){m_mainWindow.NotifyMessage(message);};m_uiSyncContext.Post(callback, message);}public bool AcceptCall(string username){//调獭?用?线?程ì必?须?为a STA，?因皑?为a许í多à UI 组哩?件t都?需è要癮。￡return MessageBox.Show(String.Format("Accep call from \"{0}\" ", username), "Incomming Call", MessageBoxButton.YesNo, MessageBoxImage.Information) == MessageBoxResult.Yes;}}
效果：

1、服务端登陆：

2、客户端登录：

3、文字聊天

4、共享白板：

总结：这篇文章实现了WPF的UI界面以及文字聊天和共享白板的功能。下一篇文章中将在此基础上实现语音通话的功能。

参考文章：

WXWinter的Silverlight例子_多人手写讨论板

Tim Callaghan, Alvin Lim的DrawMeWCF

附代码下载：http://files.cnblogs.com/zhuqil/ZqlChart.rar

（全文完）

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