sdk/samples/WFSamples/Technologies/Hosting/PersistenceHost/CS/HostApplication/Mainform.cs

   1 //---------------------------------------------------------------------
   2 //  This file is part of the Windows Workflow Foundation SDK Code Samples.
   3 //
   4 //  Copyright (C) Microsoft Corporation.  All rights reserved.
   5 //
   6 //This source code is intended only as a supplement to Microsoft
   7 //Development Tools and/or on-line documentation.  See these other
   8 //materials for detailed information regarding Microsoft code samples.
   9 //
  10 //THIS CODE AND INFORMATION ARE PROVIDED AS IS WITHOUT WARRANTY OF ANY
  11 //KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
  12 //IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
  13 //PARTICULAR PURPOSE.
  14 //---------------------------------------------------------------------
  15
  16 using System;
  17 using System.Collections.Generic;
  18 using System.Collections.Specialized;
  19 using System.ComponentModel;
  20 using System.Data;
  21 using System.Drawing;
  22 using System.IO;
  23 using System.Text;
  24 using System.Windows.Forms;
  25 using System.Workflow.Activities;
  26 using System.Workflow.Runtime;
  27 using System.Xml;
  28
  29 namespace Microsoft.Samples.Workflow.PersistenceHost
  30 {
  31     public partial class Mainform : Form
  32     {
  33         private WorkflowRuntime runtime;
  34         private DocumentApprovalService documentService;
  35         const string instanceFilename = "workflowInstances.xml";
  36
  37         public Mainform()
  38         {
  39             InitializeComponent();
  40
  41             this.runtime = new WorkflowRuntime();
  42
  43             runtime.WorkflowCompleted += new EventHandler<WorkflowCompletedEventArgs>(runtime_WorkflowCompleted);
  44
  45             // Set up runtime to unload workflow instance from memory to file using FilePersistenceService
  46             FilePersistenceService filePersistence = new FilePersistenceService(true);
  47             runtime.AddService(filePersistence);
  48
  49             // Add document approval service
  50             ExternalDataExchangeService dataService = new ExternalDataExchangeService();
  51             runtime.AddService(dataService);
  52             documentService = new DocumentApprovalService(this);
  53             dataService.AddService(documentService);
  54
  55             // Search for workflows that have previously been persisted to file, and load into the listview control.
  56             // These workflows will be reloaded by the runtime when events are raised against them.
  57             LoadWorkflowData();
  58
  59             // Start the runtime
  60             runtime.StartRuntime();
  61         }
  62
  63         internal void DocumentRequested(Guid instanceId, String approver)
  64         {
  65             AddListViewItem addListItem = new AddListViewItem(AddListViewItemAsync);
  66             Invoke(addListItem, instanceId, approver);
  67         }
  68
  69         void runtime_WorkflowCompleted(object sender, WorkflowCompletedEventArgs e)
  70         {
  71             // Remove completed workflow from list view
  72             RemoveListViewItem remove = new RemoveListViewItem(RemoveListViewItemAsync);
  73             Invoke(remove, e.WorkflowInstance.InstanceId);
  74
  75             // Remove completed workflow persistence file
  76             FileInfo file = new FileInfo(e.WorkflowInstance.InstanceId.ToString());
  77             file.Delete();
  78         }
  79
  80         #region Workflow Data Persistence
  81
  82         void LoadWorkflowData()
  83         {
  84             XmlTextReader reader = new XmlTextReader(instanceFilename);
  85             try
  86             {
  87                 while (reader.Read())
  88                 {
  89                     if (reader.Name.Equals("WorkflowInstance"))
  90                     {
  91                         ListViewExistingRequests.Items.Add(
  92                             new ListViewItem(
  93                                 new String[] { reader.GetAttribute("Approver"),
  94                                             reader.GetAttribute("InstanceId") }));
  95                     }
  96                 }
  97                 reader.Close();
  98             }
  99             catch (FileNotFoundException) { }
 100
 101         }
 102         void SaveWorkflowData()
 103         {
 104             XmlTextWriter writer = new XmlTextWriter(instanceFilename, Encoding.Unicode);
 105             writer.WriteStartElement("WorkflowInstances");
 106             foreach (ListViewItem item in ListViewExistingRequests.Items)
 107             {
 108                 writer.WriteStartElement("WorkflowInstance");
 109                 writer.WriteAttributeString("Approver", item.SubItems[0].Text);
 110                 writer.WriteAttributeString("InstanceId", item.SubItems[1].Text);
 111                 writer.WriteEndElement();
 112             }
 113             writer.WriteEndElement();
 114             writer.Flush();
 115             writer.Close();
 116         }
 117         #endregion
 118
 119         #region Asynchronous control accessors
 120
 121         // Accessing the list view control from other threads (such as are created when the workflow raises an event)
 122         // requires use of Invoke so that the calls are threadsafe
 123         private delegate void RemoveListViewItem(Guid instanceId);
 124         private void RemoveListViewItemAsync(Guid instanceId)
 125         {
 126             foreach (ListViewItem item in ListViewExistingRequests.Items)
 127             {
 128                 if (item.SubItems[1].Text.Equals(instanceId.ToString()))
 129                     ListViewExistingRequests.Items.Remove(item);
 130             }
 131         }
 132
 133         private delegate void AddListViewItem(Guid instanceId, String approver);
 134         private void AddListViewItemAsync(Guid instanceId, String approver)
 135         {
 136             ListViewExistingRequests.Items.Add(new ListViewItem(new String[] { approver, instanceId.ToString() }));
 137         }
 138
 139         #endregion
 140
 141         #region Form Events
 142         private void Mainform_FormClosing(object sender, FormClosingEventArgs e)
 143         {
 144             SaveWorkflowData();
 145             runtime.StopRuntime();
 146             runtime.Dispose();
 147         }
 148
 149         private void ButtonCreateNewRequest_Click(object sender, EventArgs e)
 150         {
 151             Dictionary<String, Object> parameters = new Dictionary<String, Object>();
 152             parameters.Add("Approver", TextBoxApprover.Text);
 153             WorkflowInstance instance = runtime.CreateWorkflow(typeof(DocumentApprovalWorkflow), parameters);
 154
 155             instance.Start();
 156
 157             TextBoxApprover.Text = String.Empty;
 158         }
 159
 160         private void ApproveDocumentToolStripMenuItem_Click(object sender, EventArgs e)
 161         {
 162             if (ListViewExistingRequests.SelectedItems.Count == 1)
 163             {
 164                 documentService.ApproveDocument(
 165                     new Guid(ListViewExistingRequests.SelectedItems[0].SubItems[1].Text),
 166                     ListViewExistingRequests.SelectedItems[0].SubItems[0].Text
 167                     );
 168             }
 169         }
 170         #endregion
 171     }
 172 }