C#生成DBF文件

摘要:
C#在不注册Microsoft.Jet.OLEDB.1namespaceConsoleApplication2{3classProgram4{5staticvoidMain(string〔〕args)6{7Test();8Console.ReadKey();9}1011privatestaticvoidTest()12{13stringtestPath=AppDomain.Current的情况下生成DBF

C# 生成DBF,无需注册Microsoft.Jet.OLEDB。

 1 namespace ConsoleApplication
 2 {
 3     class Program
 4     {
 5         static void Main(string[] args)
 6         {
 7             Test();
 8             Console.ReadKey();
 9         }
10 
11         private static void Test()
12         {
13             string testPath = AppDomain.CurrentDomain.BaseDirectory;
14             var odbf = new DbfFile(Encoding.GetEncoding(936));
15             odbf.Open(Path.Combine(testPath, "test.dbf"), FileMode.Create);
16 
17             //创建列头
18             odbf.Header.AddColumn(new DbfColumn("编号", DbfColumn.DbfColumnType.Character, 20, 0));
19             odbf.Header.AddColumn(new DbfColumn("名称", DbfColumn.DbfColumnType.Character, 20, 0));
20             odbf.Header.AddColumn(new DbfColumn("地址", DbfColumn.DbfColumnType.Character, 20, 0));
21             odbf.Header.AddColumn(new DbfColumn("时间", DbfColumn.DbfColumnType.Date));
22             odbf.Header.AddColumn(new DbfColumn("余额", DbfColumn.DbfColumnType.Number, 15, 3));
23 
24             var orec = new DbfRecord(odbf.Header) { AllowDecimalTruncate = true };
25             List<User> list = User.GetList();
26             foreach (var item in list)
27             {
28                 orec[0] = item.UserCode;
29                 orec[1] = item.UserName;
30                 orec[2] = item.Address;
31                 orec[3] = item.date.ToString("yyyy-MM-dd HH:mm:ss");
32                 orec[4] = item.money.ToString();
33                 odbf.Write(orec, true);
34             }
35             odbf.Close();
36         }
37     }
38 
39     public class User
40     {
41         public string UserCode { get; set; }
42         public string UserName { get; set; }
43         public string Address { get; set; }
44         public DateTime date { get; set; }
45         public decimal money { get; set; }
46 
47         public static List<User> GetList()
48         {
49             List<User> list = new List<User>();
50             list.Add(new User() { UserCode = "A1", UserName = "张三", Address = "上海杨浦", date = DateTime.Now, money = 1000.12m });
51             list.Add(new User() { UserCode = "A2", UserName = "李四", Address = "湖北武汉", date = DateTime.Now, money = 31000.008m });
52             list.Add(new User() { UserCode = "A3", UserName = "王子龙", Address = "陕西西安", date = DateTime.Now, money = 2000.12m });
53             list.Add(new User() { UserCode = "A4", UserName = "李三", Address = "北京", date = DateTime.Now, money = 3000.12m });
54             return list;
55         }
56     }
57 
58 }

生成的文件截图:

C#生成DBF文件第1张

操作DBF文件的部分代码:

C#生成DBF文件第2张C#生成DBF文件第3张
  1 ///
  2 /// Author: Ahmed Lacevic
  3 /// Date: 12/1/2007
  4 /// Desc: 
  5 /// 
  6 /// Revision History:
  7 /// -----------------------------------
  8 ///   Author:
  9 ///   Date:
 10 ///   Desc:
 11 
 12 
 13 using System;
 14 using System.Collections.Generic;
 15 using System.Text;
 16 using System.IO;
 17 using System.Globalization;
 18 
 19 
 20 namespace SocialExplorer.IO.FastDBF
 21 {
 22 
 23     /// <summary>
 24     /// Use this class to create a record and write it to a dbf file. You can use one record object to write all records!!
 25     /// It was designed for this kind of use. You can do this by clearing the record of all data 
 26     /// (call Clear() method) or setting values to all fields again, then write to dbf file. 
 27     /// This eliminates creating and destroying objects and optimizes memory use.
 28     /// 
 29     /// Once you create a record the header can no longer be modified, since modifying the header would make a corrupt DBF file.
 30     /// </summary>
 31     public class DbfRecord
 32     {
 33 
 34         /// <summary>
 35         /// Header provides information on all field types, sizes, precision and other useful information about the DBF.
 36         /// </summary>
 37         private DbfHeader mHeader = null;
 38 
 39         /// <summary>
 40         /// Dbf data are a mix of ASCII characters and binary, which neatly fit in a byte array.
 41         /// BinaryWriter would esentially perform the same conversion using the same Encoding class.
 42         /// </summary>
 43         private byte[] mData = null;
 44 
 45         /// <summary>
 46         /// Zero based record index. -1 when not set, new records for example.
 47         /// </summary>
 48         private int mRecordIndex = -1;
 49 
 50         /// <summary>
 51         /// Empty Record array reference used to clear fields quickly (or entire record).
 52         /// </summary>
 53         private readonly byte[] mEmptyRecord = null;
 54 
 55 
 56         /// <summary>
 57         /// Specifies whether we allow strings to be truncated. If false and string is longer than we can fit in the field, an exception is thrown.
 58         /// </summary>
 59         private bool mAllowStringTruncate = true;
 60 
 61         /// <summary>
 62         /// Specifies whether we allow the decimal portion of numbers to be truncated. 
 63         /// If false and decimal digits overflow the field, an exception is thrown.
 64         /// </summary>
 65         private bool mAllowDecimalTruncate = false;
 66 
 67         /// <summary>
 68         /// Specifies whether we allow the integer portion of numbers to be truncated.
 69         /// If false and integer digits overflow the field, an exception is thrown.
 70         /// </summary>
 71         private bool mAllowIntegerTruncate = false;
 72 
 73 
 74         //array used to clear decimals, we can clear up to 40 decimals which is much more than is allowed under DBF spec anyway.
 75         //Note: 48 is ASCII code for 0.
 76         private static readonly byte[] mDecimalClear = new byte[] {48,48,48,48,48,48,48,48,48,48,48,48,48,48,48,
 77                                                                48,48,48,48,48,48,48,48,48,48,48,48,48,48,48,
 78                                                                48,48,48,48,48,48,48,48,48,48,48,48,48,48,48};
 79 
 80 
 81         //Warning: do not make this one static because that would not be thread safe!! The reason I have 
 82         //placed this here is to skip small memory allocation/deallocation which fragments memory in .net.
 83         private int[] mTempIntVal = { 0 };
 84 
 85 
 86         //Ascii Encoder
 87         private readonly Encoding encoding = Encoding.ASCII;
 88 
 89         /// <summary>
 90         /// Column Name to Column Index map
 91         /// </summary>
 92         private readonly Dictionary<string, int> mColNameToConIdx = new Dictionary<string, int>(StringComparer.InvariantCulture);
 93 
 94 
 95 
 96         /// <summary>
 97         /// 
 98         /// </summary>
 99         /// <param name="oHeader">Dbf Header will be locked once a record is created 
100         /// since the record size is fixed and if the header was modified it would corrupt the DBF file.</param>
101         public DbfRecord(DbfHeader oHeader)
102         {
103             mHeader = oHeader;
104             mHeader.Locked = true;
105 
106             //create a buffer to hold all record data. We will reuse this buffer to write all data to the file.
107             mData = new byte[mHeader.RecordLength];
108             mEmptyRecord = mHeader.EmptyDataRecord;
109             encoding = oHeader.encoding;
110 
111             for (int i = 0; i < oHeader.mFields.Count; i++)
112                 mColNameToConIdx[oHeader.mFields[i].Name] = i;
113         }
114 
115 
116         /// <summary>
117         /// Set string data to a column, if the string is longer than specified column length it will be truncated!
118         /// If dbf column type is not a string, input will be treated as dbf column 
119         /// type and if longer than length an exception will be thrown.
120         /// </summary>
121         /// <param name="nColIndex"></param>
122         /// <returns></returns>
123         public string this[int nColIndex]
124         {
125 
126             set
127             {
128 
129                 DbfColumn ocol = mHeader[nColIndex];
130                 DbfColumn.DbfColumnType ocolType = ocol.ColumnType;
131 
132 
133                 //
134                 //if an empty value is passed, we just clear the data, and leave it blank.
135                 //note: test have shown that testing for null and checking length is faster than comparing to "" empty str :)
136                 //------------------------------------------------------------------------------------------------------------
137                 if (string.IsNullOrEmpty(value))
138                 {
139                     //this is like NULL data, set it to empty. i looked at SAS DBF output when a null value exists 
140                     //and empty data are output. we get the same result, so this looks good.
141                     Buffer.BlockCopy(mEmptyRecord, ocol.DataAddress, mData, ocol.DataAddress, ocol.Length);
142 
143                 }
144                 else
145                 {
146 
147                     //set values according to data type:
148                     //-------------------------------------------------------------
149                     if (ocolType == DbfColumn.DbfColumnType.Character)
150                     {
151                         if (!mAllowStringTruncate && value.Length > ocol.Length)
152                             throw new DbfDataTruncateException("Value not set. String truncation would occur and AllowStringTruncate flag is set to false. To supress this exception change AllowStringTruncate to true.");
153 
154                         //BlockCopy copies bytes.  First clear the previous value, then set the new one.
155                         Buffer.BlockCopy(mEmptyRecord, ocol.DataAddress, mData, ocol.DataAddress, ocol.Length);
156                         encoding.GetBytes(value, 0, value.Length > ocol.Length ? ocol.Length : value.Length, mData, ocol.DataAddress);
157 
158                     }
159                     else if (ocolType == DbfColumn.DbfColumnType.Number)
160                     {
161 
162                         if (ocol.DecimalCount == 0)
163                         {
164 
165                             //integers
166                             //----------------------------------
167 
168                             //throw an exception if integer overflow would occur
169                             if (!mAllowIntegerTruncate && value.Length > ocol.Length)
170                                 throw new DbfDataTruncateException("Value not set. Integer does not fit and would be truncated. AllowIntegerTruncate is set to false. To supress this exception set AllowIntegerTruncate to true, although that is not recomended.");
171 
172 
173                             //clear all numbers, set to [space].
174                             //-----------------------------------------------------
175                             Buffer.BlockCopy(mEmptyRecord, 0, mData, ocol.DataAddress, ocol.Length);
176 
177 
178                             //set integer part, CAREFUL not to overflow buffer! (truncate instead)
179                             //-----------------------------------------------------------------------
180                             int nNumLen = value.Length > ocol.Length ? ocol.Length : value.Length;
181                             encoding.GetBytes(value, 0, nNumLen, mData, (ocol.DataAddress + ocol.Length - nNumLen));
182 
183                         }
184                         else
185                         {
186 
187                             ///TODO: we can improve perfomance here by not using temp char arrays cDec and cNum,
188                             ///simply direcly copy from source string using encoding!
189 
190 
191                             //break value down into integer and decimal portions
192                             //--------------------------------------------------------------------------
193                             int nidxDecimal = value.IndexOf('.'); //index where the decimal point occurs
194                             char[] cDec = null; //decimal portion of the number
195                             char[] cNum = null; //integer portion
196 
197                             if (nidxDecimal > -1)
198                             {
199                                 cDec = value.Substring(nidxDecimal + 1).Trim().ToCharArray();
200                                 cNum = value.Substring(0, nidxDecimal).ToCharArray();
201 
202                                 //throw an exception if decimal overflow would occur
203                                 if (!mAllowDecimalTruncate && cDec.Length > ocol.DecimalCount)
204                                     throw new DbfDataTruncateException("Value not set. Decimal does not fit and would be truncated. AllowDecimalTruncate is set to false. To supress this exception set AllowDecimalTruncate to true.");
205 
206                             }
207                             else
208                                 cNum = value.ToCharArray();
209 
210 
211                             //throw an exception if integer overflow would occur
212                             if (!mAllowIntegerTruncate && cNum.Length > ocol.Length - ocol.DecimalCount - 1)
213                                 throw new DbfDataTruncateException("Value not set. Integer does not fit and would be truncated. AllowIntegerTruncate is set to false. To supress this exception set AllowIntegerTruncate to true, although that is not recomended.");
214 
215 
216 
217                             //clear all decimals, set to 0.
218                             //-----------------------------------------------------
219                             Buffer.BlockCopy(mDecimalClear, 0, mData, (ocol.DataAddress + ocol.Length - ocol.DecimalCount), ocol.DecimalCount);
220 
221                             //clear all numbers, set to [space].
222                             Buffer.BlockCopy(mEmptyRecord, 0, mData, ocol.DataAddress, (ocol.Length - ocol.DecimalCount));
223 
224 
225 
226                             //set decimal numbers, CAREFUL not to overflow buffer! (truncate instead)
227                             //-----------------------------------------------------------------------
228                             if (nidxDecimal > -1)
229                             {
230                                 int nLen = cDec.Length > ocol.DecimalCount ? ocol.DecimalCount : cDec.Length;
231                                 encoding.GetBytes(cDec, 0, nLen, mData, (ocol.DataAddress + ocol.Length - ocol.DecimalCount));
232                             }
233 
234                             //set integer part, CAREFUL not to overflow buffer! (truncate instead)
235                             //-----------------------------------------------------------------------
236                             int nNumLen = cNum.Length > ocol.Length - ocol.DecimalCount - 1 ? (ocol.Length - ocol.DecimalCount - 1) : cNum.Length;
237                             encoding.GetBytes(cNum, 0, nNumLen, mData, ocol.DataAddress + ocol.Length - ocol.DecimalCount - nNumLen - 1);
238 
239 
240                             //set decimal point
241                             //-----------------------------------------------------------------------
242                             mData[ocol.DataAddress + ocol.Length - ocol.DecimalCount - 1] = (byte)'.';
243 
244 
245                         }
246 
247 
248                     }
249                     else if (ocolType == DbfColumn.DbfColumnType.Integer)
250                     {
251                         //note this is a binary Integer type!
252                         //----------------------------------------------
253 
254                         ///TODO: maybe there is a better way to copy 4 bytes from int to byte array. Some memory function or something.
255                         mTempIntVal[0] = Convert.ToInt32(value);
256                         Buffer.BlockCopy(mTempIntVal, 0, mData, ocol.DataAddress, 4);
257 
258                     }
259                     else if (ocolType == DbfColumn.DbfColumnType.Memo)
260                     {
261                         //copy 10 digits...
262                         ///TODO: implement MEMO
263 
264                         throw new NotImplementedException("Memo data type functionality not implemented yet!");
265 
266                     }
267                     else if (ocolType == DbfColumn.DbfColumnType.Boolean)
268                     {
269                         if (String.Compare(value, "true", true) == 0 || String.Compare(value, "1", true) == 0 ||
270                             String.Compare(value, "T", true) == 0 || String.Compare(value, "yes", true) == 0 ||
271                             String.Compare(value, "Y", true) == 0)
272                             mData[ocol.DataAddress] = (byte)'T';
273                         else if (value == " " || value == "?")
274                             mData[ocol.DataAddress] = (byte)'?';
275                         else
276                             mData[ocol.DataAddress] = (byte)'F';
277 
278                     }
279                     else if (ocolType == DbfColumn.DbfColumnType.Date)
280                     {
281                         //try to parse out date value using Date.Parse() function, then set the value
282                         DateTime dateval;
283                         if (DateTime.TryParse(value, out dateval))
284                         {
285                             SetDateValue(nColIndex, dateval);
286                         }
287                         else
288                             throw new InvalidOperationException("Date could not be parsed from source string! Please parse the Date and set the value (you can try using DateTime.Parse() or DateTime.TryParse() functions).");
289 
290                     }
291                     else if (ocolType == DbfColumn.DbfColumnType.Binary)
292                         throw new InvalidOperationException("Can not use string source to set binary data. Use SetBinaryValue() and GetBinaryValue() functions instead.");
293 
294                     else
295                         throw new InvalidDataException("Unrecognized data type: " + ocolType.ToString());
296 
297                 }
298 
299             }
300 
301             get
302             {
303                 DbfColumn ocol = mHeader[nColIndex];
304                 return new string(encoding.GetChars(mData, ocol.DataAddress, ocol.Length));
305 
306             }
307         }
308 
309         /// <summary>
310         /// Set string data to a column, if the string is longer than specified column length it will be truncated!
311         /// If dbf column type is not a string, input will be treated as dbf column 
312         /// type and if longer than length an exception will be thrown.
313         /// </summary>
314         /// <param name="nColName"></param>
315         /// <returns></returns>
316         public string this[string nColName]
317         {
318             get
319             {
320                 if (mColNameToConIdx.ContainsKey(nColName))
321                     return this[mColNameToConIdx[nColName]];
322                 throw new InvalidOperationException(string.Format("There's no column with name '{0}'", nColName));
323             }
324             set
325             {
326                 if (mColNameToConIdx.ContainsKey(nColName))
327                     this[mColNameToConIdx[nColName]] = value;
328                 else
329                     throw new InvalidOperationException(string.Format("There's no column with name '{0}'", nColName));
330             }
331         }
332 
333         /// <summary>
334         /// Get date value.
335         /// </summary>
336         /// <param name="nColIndex"></param>
337         /// <returns></returns>
338         public DateTime GetDateValue(int nColIndex)
339         {
340             DbfColumn ocol = mHeader[nColIndex];
341 
342             if (ocol.ColumnType == DbfColumn.DbfColumnType.Date)
343             {
344                 string sDateVal = encoding.GetString(mData, ocol.DataAddress, ocol.Length);
345                 return DateTime.ParseExact(sDateVal, "yyyyMMdd", CultureInfo.InvariantCulture);
346 
347             }
348             else
349                 throw new Exception("Invalid data type. Column '" + ocol.Name + "' is not a date column.");
350 
351         }
352 
353 
354         /// <summary>
355         /// Get date value.
356         /// </summary>
357         /// <param name="nColIndex"></param>
358         /// <returns></returns>
359         public void SetDateValue(int nColIndex, DateTime value)
360         {
361 
362             DbfColumn ocol = mHeader[nColIndex];
363             DbfColumn.DbfColumnType ocolType = ocol.ColumnType;
364 
365 
366             if (ocolType == DbfColumn.DbfColumnType.Date)
367             {
368 
369                 //Format date and set value, date format is like this: yyyyMMdd
370                 //-------------------------------------------------------------
371                 encoding.GetBytes(value.ToString("yyyyMMdd"), 0, ocol.Length, mData, ocol.DataAddress);
372 
373             }
374             else
375                 throw new Exception("Invalid data type. Column is of '" + ocol.ColumnType.ToString() + "' type, not date.");
376 
377 
378         }
379 
380 
381         /// <summary>
382         /// Clears all data in the record.
383         /// </summary>
384         public void Clear()
385         {
386             Buffer.BlockCopy(mEmptyRecord, 0, mData, 0, mEmptyRecord.Length);
387             mRecordIndex = -1;
388 
389         }
390 
391 
392         /// <summary>
393         /// returns a string representation of this record.
394         /// </summary>
395         /// <returns></returns>
396         public override string ToString()
397         {
398             return new string(encoding.GetChars(mData));
399         }
400 
401 
402         /// <summary>
403         /// Gets/sets a zero based record index. This information is not directly stored in DBF. 
404         /// It is the location of this record within the DBF. 
405         /// </summary>
406         /// <remarks>
407         /// This property is managed from outside this object,
408         /// CDbfFile object updates it when records are read. The reason we don't set it in the Read() 
409         /// function within this object is that the stream can be forward-only so the Position property 
410         /// is not available and there is no way to figure out what index the record was unless you 
411         /// count how many records were read, and that's exactly what CDbfFile does.
412         /// </remarks>
413         public int RecordIndex
414         {
415             get
416             {
417                 return mRecordIndex;
418             }
419             set
420             {
421                 mRecordIndex = value;
422             }
423         }
424 
425 
426         /// <summary>
427         /// Returns/sets flag indicating whether this record was tagged deleted. 
428         /// </summary>
429         /// <remarks>Use CDbf4File.Compress() function to rewrite dbf removing records flagged as deleted.</remarks>
430         /// <seealso cref="CDbf4File.Compress() function"/>
431         public bool IsDeleted
432         {
433             get { return mData[0] == '*'; }
434             set { mData[0] = value ? (byte)'*' : (byte)' '; }
435         }
436 
437 
438         /// <summary>
439         /// Specifies whether strings can be truncated. If false and string is longer than can fit in the field, an exception is thrown.
440         /// Default is True.
441         /// </summary>
442         public bool AllowStringTurncate
443         {
444             get { return mAllowStringTruncate; }
445             set { mAllowStringTruncate = value; }
446         }
447 
448         /// <summary>
449         /// Specifies whether to allow the decimal portion of numbers to be truncated. 
450         /// If false and decimal digits overflow the field, an exception is thrown. Default is false.
451         /// </summary>
452         public bool AllowDecimalTruncate
453         {
454             get { return mAllowDecimalTruncate; }
455             set { mAllowDecimalTruncate = value; }
456         }
457 
458 
459         /// <summary>
460         /// Specifies whether integer portion of numbers can be truncated.
461         /// If false and integer digits overflow the field, an exception is thrown. 
462         /// Default is False.
463         /// </summary>
464         public bool AllowIntegerTruncate
465         {
466             get { return mAllowIntegerTruncate; }
467             set { mAllowIntegerTruncate = value; }
468         }
469 
470 
471         /// <summary>
472         /// Returns header object associated with this record.
473         /// </summary>
474         public DbfHeader Header
475         {
476             get
477             {
478                 return mHeader;
479             }
480         }
481 
482 
483         /// <summary>
484         /// Get column by index.
485         /// </summary>
486         /// <param name="index"></param>
487         /// <returns></returns>
488         public DbfColumn Column(int index)
489         {
490             return mHeader[index];
491         }
492 
493         /// <summary>
494         /// Get column by name.
495         /// </summary>
496         /// <param name="index"></param>
497         /// <returns></returns>
498         public DbfColumn Column(string sName)
499         {
500             return mHeader[sName];
501         }
502 
503         /// <summary>
504         /// Gets column count from header.
505         /// </summary>
506         public int ColumnCount
507         {
508             get
509             {
510                 return mHeader.ColumnCount;
511             }
512         }
513 
514         /// <summary>
515         /// Finds a column index by searching sequentially through the list. Case is ignored. Returns -1 if not found.
516         /// </summary>
517         /// <param name="sName">Column name.</param>
518         /// <returns>Column index (0 based) or -1 if not found.</returns>
519         public int FindColumn(string sName)
520         {
521             return mHeader.FindColumn(sName);
522         }
523 
524         /// <summary>
525         /// Writes data to stream. Make sure stream is positioned correctly because we simply write out the data to it.
526         /// </summary>
527         /// <param name="osw"></param>
528         protected internal void Write(Stream osw)
529         {
530             osw.Write(mData, 0, mData.Length);
531 
532         }
533 
534 
535         /// <summary>
536         /// Writes data to stream. Make sure stream is positioned correctly because we simply write out data to it, and clear the record.
537         /// </summary>
538         /// <param name="osw"></param>
539         protected internal void Write(Stream obw, bool bClearRecordAfterWrite)
540         {
541             obw.Write(mData, 0, mData.Length);
542 
543             if (bClearRecordAfterWrite)
544                 Clear();
545 
546         }
547 
548 
549         /// <summary>
550         /// Read record from stream. Returns true if record read completely, otherwise returns false.
551         /// </summary>
552         /// <param name="obr"></param>
553         /// <returns></returns>
554         protected internal bool Read(Stream obr)
555         {
556             return obr.Read(mData, 0, mData.Length) >= mData.Length;
557         }
558 
559         protected internal string ReadValue(Stream obr, int colIndex)
560         {
561             DbfColumn ocol = mHeader[colIndex];
562             return new string(encoding.GetChars(mData, ocol.DataAddress, ocol.Length));
563 
564         }
565 
566     }
567 }
View Code

完整代码下载(含FastDBF源代码):下载

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Java switch 枚举

Switch可以使用int.short、char、Enum和String其中,Enum是1.5之后的新特性,String是java8的新特性。所以正确的写作应该如下。...

无法将您的Kindle连接到Wi-Fi网络怎么办-kindle无法连接wifi-kindle无法连接手机热点

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微信支付服务商模式支付与普通微信支付的配置区别

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Oracle11g温习-第七章:redo日志

thread:线程,在单实例的环境下,thread#永远是1sequence:日志序列号。在日志切换时会递增。FIRST_CHANGE#:在当前日志中记录的首个数据块的scn。...