[C#]DropBox開發系列 - 使用DropNet進行DropBox的二次登入

筆者在[C#]DropBox開發系列 - 使用DropNet進行DropBox的OAuth認證這篇稍稍介紹了一下怎樣用DropNet去登入DropBox帳號，並授權給應用程式存取DropBox。這樣的登入與授權的動作在應用程式中不會每次都做，通常是第一次做了取得Token後，再次登入時就改成用帶入Token的方式去做認證，只要Token尚未過期基本上都不會再次要求授權。

使用DropNet進行這樣的處理很簡單，DropNetClient類別有兩個建構子，有個建構子允許我們帶入userToken與userSecret。 public DropNetClient(string apiKey, string appSecret); public DropNetClient(string apiKey, string appSecret, string userToken, string userSecret);

而我們再做完OAuth認證後取得的AccessToken就內含userToken與userSecret這兩個值，我們只需要在第一次做完認證時將這兩個值儲存起來，在下次認證時一併帶入建構子中建立DropNetClient就可以了。或是後續再透過DropNetClient.UserLogin來設定也可以。

像是下面這樣：

		...
		if (!String.IsNullOrEmpty(Properties.Settings.Default.SECRET) && !String.IsNullOrEmpty(Properties.Settings.Default.TOKEN))
		{
			m_DropNetClient.UserLogin = new UserLogin() 
			{
				Secret = Properties.Settings.Default.SECRET,
				Token = Properties.Settings.Default.TOKEN
			};

			return;
		}
		
		...
		if (DoOAuth(callbackUrl, cancelCallbackUrl, size) == DialogResult.OK)
		{
			var accessToken = m_DropNetClient.GetAccessToken();
			Properties.Settings.Default.SECRET = accessToken.Secret;
			Properties.Settings.Default.TOKEN = accessToken.Token;
			Properties.Settings.Default.Save();
		}

這邊的程式筆者是在取得AccessToken後將Secret與Token存入設定檔中，下次認證時若是設定檔中有就直接取用。

最後一樣附上完整的範例程式：

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using DropNet; using DropNetDemo.Properties; using DropNet.Models;

namespace DropNetDemo { public partial class Form1 : Form { #region Var private DropNetClient _dropNetClient; #endregion

	#region Private Property
	private DropNetClient m_DropNetClient
	{
		get
		{
			return _dropNetClient ?? (_dropNetClient = new DropNetClient(tbxAppKey.Text, tbxAppSecret.Text));
		}
		set
		{
			_dropNetClient = value;
		}
	}
	#endregion

	public Form1()
	{
		InitializeComponent();
	}

	private void SetSecretAndToken(string secret, string token)
	{
		Settings.Default.SECRET = secret;
		Settings.Default.TOKEN = token;
	}

	private void btnLogin_Click(object sender, EventArgs e)
	{
		if (!String.IsNullOrEmpty(Properties.Settings.Default.SECRET) && !String.IsNullOrEmpty(Properties.Settings.Default.TOKEN))
		{
			m_DropNetClient.UserLogin = new UserLogin() 
			{
				Secret = Properties.Settings.Default.SECRET,
				Token = Properties.Settings.Default.TOKEN
			};
			return;
		}

		var callbackUrl = "https://www.dropbox.com/1/oauth/authorize";
		var cancelCallbackUrl = "https://www.dropbox.com/home";
		var size = new Size(1024, 600);

		if (DoOAuth(callbackUrl, cancelCallbackUrl, size) == DialogResult.OK)
		{
			var accessToken = m_DropNetClient.GetAccessToken();
			Properties.Settings.Default.SECRET = accessToken.Secret;
			Properties.Settings.Default.TOKEN = accessToken.Token;
			Properties.Settings.Default.Save();
		}
	}

	private DialogResult DoOAuth(string callbackUrl, string cancelCallbackUrl, System.Drawing.Size size)
	{
		using (var dialog = new Form())
		{
			var browesr = new WebBrowser()
			{
				Dock = DockStyle.Fill
			};

			var token = m_DropNetClient.GetToken();
			var authUrl = m_DropNetClient.BuildAuthorizeUrl();
			browesr.Navigated += (s, ex) =>
			{
				var url = ex.Url.ToString();
				if (url.Equals(callbackUrl))
				{
					dialog.DialogResult = DialogResult.OK;
				}
				else if (url.Equals(cancelCallbackUrl))
				{
					dialog.DialogResult = DialogResult.Cancel;
				}
			};
			browesr.Navigate(authUrl);

			dialog.Size = size;
			dialog.Controls.Add(browesr);

			return dialog.ShowDialog();
		}
	}

	private void tbxAppKey_TextChanged(object sender, EventArgs e)
	{
		m_DropNetClient = null;
	}
}

}