源码:处理文件格式和字符集的相关代码(3-3)
总入口:源码:处理文件格式和字符集的相关代码(3-1)-CSDN博客
目录
六、预览(正确显示文本文件)
6.1 总体逻辑
6.2 二进制显示
6.3 文本显示
六、预览(正确显示文本文件)
6.1 总体逻辑
首先区分了二进制显示和文本显示,这是两种完全不同的方法。
文本显示默认根据检测到的编码来显示,如果指定了编码,则跳过BOM,否则系统会根据BOM来显示(这样指定的编码就没有意义了)。
public static string makeFileContent(string file, bool bHex, Encoding encoding, ref string state, ref Encoding realEncoding){if (bHex){。。。。。。二进制显示}else{。。。。。。文本显示}}
6.2 二进制显示
二进制显示根据检测到的格式来处理回车换行。每个回车和换行都导致换行显示(当然,这是我懒了)。
state = "HEX";FileResult fileResult = ProcessFile(file, true);FileStream filestream = new FileStream(file, FileMode.Open, FileAccess.Read);byte[] data = new byte[filestream.Length];filestream.Read(data, 0, (int)filestream.Length);filestream.Close();StringBuilder sb = new StringBuilder();bool linehead = true;int charWidth = 1;int pos = 0;if (fileResult.isUTF16){charWidth = 2;pos = (fileResult.isBigEndian ? charWidth - 1 : 0);}if (fileResult.isUTF32){charWidth = 4;pos = (fileResult.isBigEndian ? charWidth - 1 : 0);}for (int i = 0; i < data.Length; i += charWidth){int sum = 0;for (int j = 0; j < charWidth; ++j){string str = Convert.ToString(data[i + j], 16);if (!linehead) sb.Append(" ");if (str.Length == 1) sb.Append("0");sb.Append(str);linehead = false;sum += data[i + j];}if (sum == '\r' && data[i + pos] == '\r'){sb.Append(Environment.NewLine);linehead = true;}if (sum == '\n' && data[i + pos] == '\n'){sb.Append(Environment.NewLine);linehead = true;}}return sb.ToString();
6.3 文本显示
文本显示利用的是系统的处理文本的功能。
FileResult fileResult = ProcessFile(file, true);FileStream fileStream = new FileStream(file, FileMode.Open, FileAccess.Read);Encoding tryencoding;if (null == encoding){if (fileResult.isUTF8) tryencoding = Encoding.UTF8;else if (fileResult.isUTF16) tryencoding = Encoding.Unicode;else if (fileResult.isUTF32) tryencoding = Encoding.UTF32;else tryencoding = Encoding.Default;if (fileResult.isBigEndian){if (fileResult.isUTF16) tryencoding = Encoding.GetEncoding(1201);if (fileResult.isUTF32) tryencoding = Encoding.GetEncoding(12001);}}else{//指定编码时跳过BOM,以免自动根据BOM改变编码tryencoding = encoding;int BOMsize = 0;if (fileResult.withBOM){if (fileResult.isUTF8) BOMsize = 3;if (fileResult.isUTF16) BOMsize = 2;if (fileResult.isUTF32) BOMsize = 4;}for (int i = 0; i < BOMsize; ++i){fileStream.ReadByte();}}StreamReader streamReader = new StreamReader(fileStream, tryencoding);StringBuilder sb = new StringBuilder();string content;while ((content = streamReader.ReadLine()) != null){sb.AppendLine(content);}realEncoding = streamReader.CurrentEncoding;state = streamReader.CurrentEncoding.EncodingName;if (fileResult.BOM.Length > 0) state += " BOM: " + fileResult.BOM;else state += " BOM: NONE";streamReader.Close();fileStream.Close();return sb.ToString();}
(这里是文档结束)