Good Man: Windows Phone

Windows Phone SDK 是不支援 BIG5 編碼的，它只支援三種編碼。

BigEndianUnicode、Unicode、UTF8

因此若要讀取 BIG5 的網頁，就必須自行將 BIG5 轉換為 Unicode，實作的主要重點在於：

取得 BIG5 –> Unicode 轉換表。(BIG5.TXT)
將轉換表改用 Dictionary 型態儲存。
讀取網頁時，用 stream，不要用 WebClient！

使用 WebClient 來讀取網頁，得到的並非是 raw data，而是已被 default encoding 轉換過的 data。更進一步解釋，就是使用了 UTF8 –> Unicode 轉換表來轉換 BIG5 的資料，這會導致資料整個變成不可用的亂碼。

實作

將 BIG5.TXT 加入專案

在 ContentPanel 加入一個 textBlock

MainPage.xaml.cs

using System;using System.Collections.Generic;using System.Linq;using System.Net;using System.Windows;using System.Windows.Controls;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Animation;using System.Windows.Shapes;using Microsoft.Phone.Controls; using System.IO;using System.Globalization;using System.Diagnostics;using System.Text; namespace PhoneApp2{    public partial class MainPage : PhoneApplicationPage    {        // async http        delegate void DownDelegate(string content);        DownDelegate downDelegate;         // Big5 to Unicode mapping table        private static Dictionary<int, int> mBIG5_Unicode_MAP = new Dictionary<int, int>();         // 建構函式        public MainPage()        {            InitializeComponent();            createBig5ToUnicodeDictionary();            readBig5WebPage();        }         private void setConent(string content)        {            textBlock1.Text = content;        }         private void createBig5ToUnicodeDictionary()        {            var resource = Application.GetResourceStream(new Uri("BIG5.TXT", UriKind.Relative));            StreamReader sr = new StreamReader(resource.Stream);            string line;            while ((line = sr.ReadLine()) != null)            {                // 忽略註解                if (line.StartsWith("#")) continue;                string[] lTokens = line.Split(new char[] {'\t'});                mBIG5_Unicode_MAP.Add(hexToInt(lTokens[0].Substring(2)), hexToInt(lTokens[1].Substring(2)));            }        }         private void readBig5WebPage()        {            textBlock1.Text = "讀取中...";            string url = "http://www.businessweekly.com.tw/feednews.php";            downDelegate = setConent;            System.Net.WebRequest request = HttpWebRequest.Create(url);            IAsyncResult result = request.BeginGetResponse(ResponseCallback, request);        }         private void ResponseCallback(IAsyncResult result)        {            HttpWebRequest request = (HttpWebRequest)result.AsyncState;            WebResponse response = request.EndGetResponse(result);            Stream s = response.GetResponseStream();            Dispatcher.BeginInvoke(downDelegate, big5ToUnicode(s).ToString());        }         private StringBuilder big5ToUnicode(Stream s)        {            StringBuilder lSB = new StringBuilder();            byte[] big5Buffer = new byte[2];            int input;            while ((input = s.ReadByte()) != -1)            {                if (input > 0x81 && big5Buffer[0] == 0)                {                    big5Buffer[0] = (byte)input;                }                else if (big5Buffer[0] != 0)                {                    big5Buffer[1] = (byte)input;                    int Big5Char = (big5Buffer[0] << 8) + big5Buffer[1];                    try                    {                        int UTF8Char = mBIG5_Unicode_MAP[Big5Char];                        lSB.Append((char)UTF8Char);                    }                    catch (Exception)                    {                        lSB.Append((char)mBIG5_Unicode_MAP[0xA148]);                    }                     big5Buffer = new byte[2];                }                else                {                    lSB.Append((char)input);                }            }            return lSB;        }         private int hexToInt(string hexString)        {            return int.Parse(hexString, NumberStyles.HexNumber);        }    }}