[C#]DropBox開發系列 - 使用DropNet下載DropBox內存放的檔案 | Level Up - 點部落

2012-08-13

[C#]DropBox開發系列 - 使用DropNet下載DropBox內存放的檔案

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C#

[C#]DropBox開發系列 - 使用DropNet下載DropBox內存放的檔案

要使用DropNet下載DropBox內存放的檔案，我們可以透過DropNetClient.GetFile來做，將我們想要下載的檔案位置帶入該函式，會將指定檔案的內容回傳，因此成式撰寫起來會像下面這樣：

			var selectedNode = treeView1.SelectedNode;
			if (selectedNode == null)
				return;

			var metaData = selectedNode.Tag as MetaData;
			if(metaData == null)
				return;

			using (var saveFileDialog = new SaveFileDialog())
			{
				saveFileDialog.FileName = metaData.Name;

				if(saveFileDialog.ShowDialog() == DialogResult.OK)
				{
					var fileData = m_DropNetClient.GetFile(metaData.Path);
					File.WriteAllBytes(saveFileDialog.FileName, fileData);
				}
			}
			...

實際運作起來會像下面這樣，假設我嚐試要抓取的是Batch目錄下的Close.bat檔。

下載時會先詢問要存放的檔案位置，這邊為了方便就先將檔案放在桌面上。

按下儲存後桌面上會有我們剛剛所選取的檔案，將檔案開起來查驗，可以看到檔案確確實實的下載下來了。

筆者在撰寫時為了方便都是以同步的方式下去做說明，實際使用時若有需要可以考慮用非同步的方式叫用，將程式改呼叫GetFileAsync就可以了。

最後一樣附上完整的使用範例：

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;
using System.IO;

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
				};

				FillTreeView();
				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();

				FillTreeView();
			}
		}

		private void FillTreeView()
		{
			treeView1.Nodes.Clear();
			var metaData = m_DropNetClient.GetMetaData("/");

			FillDirOrFileToTreeView(null, metaData);
		}

		private void FillDirOrFileToTreeView(TreeNode parentNode, MetaData metaData)
		{
			if (metaData.Contents == null)
				return;

			var nodes = (parentNode == null) ? treeView1.Nodes : parentNode.Nodes;
			try
			{
				treeView1.BeginUpdate();
				foreach (var childMetaData in metaData.Contents)
				{
					if (childMetaData.Is_Dir)
					{
						var node = nodes.Add(childMetaData.Name);
						node.Tag = childMetaData;
						node.Nodes.Add(string.Empty);
					}
					else
					{
						nodes.Add(childMetaData.Name).Tag = childMetaData;
					}
				}
			}
			finally
			{
				treeView1.EndUpdate();
			}
		}

		private void treeView1_BeforeExpand(object sender, TreeViewCancelEventArgs e)
		{
			var node = e.Node;

			if (!(node.Nodes.Count == 1 && node.Nodes[0].Tag == null))
				return;

			node.Nodes.Clear();

			FillDirOrFileToTreeView(node, m_DropNetClient.GetMetaData("/" + node.FullPath));
		}

		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;
		}

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

		private void treeView1_MouseDoubleClick(object sender, MouseEventArgs e)
		{
			var selectedNode = treeView1.SelectedNode;
			if (selectedNode == null)
				return;

			var metaData = selectedNode.Tag as MetaData;
			if(metaData == null)
				return;

			using (var saveFileDialog = new SaveFileDialog())
			{
				saveFileDialog.FileName = metaData.Name;

				if(saveFileDialog.ShowDialog() == DialogResult.OK)
				{
					var fileData = m_DropNetClient.GetFile(metaData.Path);
					File.WriteAllBytes(saveFileDialog.FileName, fileData);
				}
			}
		}
	}
}

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