VSTO学习笔记（四）从SharePoint 2010中下载文件

上一次我们开发了一个简单的64位COM加载项，虽然功能很简单，但是包括了开发一个64位COM加载项的大部分过程。本次我们来给COM加载项添加一些功能：从SharePoint 2010的文档库中下载一个Excel文档到本地。

示例代码下载

本系列所有示例代码均在 Visual Studio 2010 Ultimate RC + Office 2010 Professional Plus Beta x64 上测试通过。

1、首先创建一个Shared AddIn项目（具体细节请参阅上一篇文章）：

2、添加引用：

Microsoft.SharePoint

System.Windows.Forms

System.Drawing

System.DirectoryServices

3、在Connect类中创建Application和COMAddIn的实例：

代码

    /// <summary>
    ///   The object for implementing an Add-in.
    /// </summary>
    /// <seealso class='IDTExtensibility2' />
    [GuidAttribute("6D3788F4-9529-429E-BA5D-09695F85687A"), ProgId("SimpleExcelServicesDemo.Connect")]
    public class Connect : Object, Extensibility.IDTExtensibility2
    {
        private Microsoft.Office.Interop.Excel.Application app;
        private Microsoft.Office.Core.COMAddIn addIn;

3、在OnConnection事件里初始化：

代码

        public void OnConnection(object application, Extensibility.ext_ConnectMode connectMode, object addInInst, ref System.Array custom)
        {
            this.app = application as Microsoft.Office.Interop.Excel.Application;
            this.addIn = addInInst as Microsoft.Office.Core.COMAddIn;
        }

4、在OnStartupComplete事件中设置一个按钮，关联事件处理逻辑：

代码

        public void OnStartupComplete(ref System.Array custom)
        {
            CommandBars commandBars;
            CommandBar standardBar下载数据;
            CommandBarButton simpleButton下载数据;
            commandBars = this.app.CommandBars;

            // Get the standard CommandBar from Word
            standardBar下载数据 = commandBars["Standard"];

            try
            {
                // try to reuse the button is hasn't already been deleted
                simpleButton下载数据 = (CommandBarButton)standardBar下载数据.Controls["下载数据"];
            }
            catch (System.Exception)
            {
                // If it's not there add a new button
                simpleButton下载数据 = (CommandBarButton)standardBar下载数据.Controls.Add(1);
                simpleButton下载数据.Caption = "下载数据";
                simpleButton下载数据.Style = MsoButtonStyle.msoButtonCaption;
            }

            // Make sure the button is visible
            simpleButton下载数据.Visible = true;
            simpleButton下载数据.Click += new _CommandBarButtonEvents_ClickEventHandler(btnDownload_Click);

            standardBar下载数据 = null;
            commandBars = null;
        }

5、做一个域用户验证，当用户输入了合法的与用户名和密码后，才允许下载。这里添加了一个WindowsForm到项目中:

6、域用户验证逻辑，我本机是一台域控制器BROOKS.COM，使用的静态IP: 192.168.1.100，【LDAP://192.168.1.100/DC=BROOKS,DC=com】是LDAP的路径语法：

代码

        private bool fn数据验证()
        {
            if (this.txt用户名.Text.Trim() == string.Empty)
            {
                MessageBox.Show("用户名不能为空！");
                this.txt用户名.Focus();
                return true;
            }

            if (this.txt密码.Text.Trim() == string.Empty)
            {
                MessageBox.Show("密码不能为空！");
                this.txt密码.Focus();
                return true;
            }

            if (this.fn域用户验证(@"LDAP://192.168.1.100/DC=BROOKS,DC=com", this.txt用户名.Text.Trim(), this.txt密码.Text.Trim()))
            {
                MessageBox.Show("您输入的用户名或密码错误，请重新输入！");
                this.txt密码.Clear();
                this.txt密码.Focus();
                return true;
            }
            return false;
        }

        private bool fn域用户验证(string path, string username, string pwd)
        {
            try
            {
                DirectoryEntry entry = new DirectoryEntry(path, username, pwd);
                DirectorySearcher search = new DirectorySearcher(entry);
                search.Filter = "(SAMAccountName=" + username + ")";
                SearchResult result = search.FindOne();

                if (null == result)
                {
                    return true;
                }
                else
                {
                    return false;
                }
            }
            catch
            {
                return true;
            }
        }

7、使用Windows Server 2008 R2的AD管理器创建一个域用户：test

8、在Connect中编写下载文件逻辑：

SharePoint 2010 网站是：http://brookspc/sites/doc，我们要下载的就是其Document库中的Excel Services Test.xlsx。

代码

        private void fn下载文件()
        {
            //保存文件
            using (SPSite site = new SPSite("http://brookspc/sites/doc"))
            {
                SPWeb web = site.OpenWeb();
                string __fileName = "http://brookspc/sites/doc/Documents/Excel Services Test.xlsx";
                SPFile file = web.GetFile(__fileName);
                string __localFilePath = @"C:\ExcelServices.xlsx";
                //将文件下载到本地
                byte[] content = file.OpenBinary();
                if (File.Exists(__localFilePath))
                {
                    File.Delete(__localFilePath);
                }
                FileStream fs = new FileStream(__localFilePath, FileMode.Create);
                fs.Write(content, 0, content.Length);
                fs.Flush();
                fs.Close();
            }
        }

9、按钮事件处理逻辑：

代码

        public void btnDownload_Click(CommandBarButton sender, ref bool cancelDefault)
        {
            FrmLogin login = new FrmLogin();
            if (login.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                this.fn下载文件();
            }
        }

10、编译一下，安装生成的setup.exe：