Method records for ASP. NET DataTable Export Excel (Third party)

Official website: http://npoi.codeplex.com/

Simple application, the main is to achieve the simple effect we want, hehe

Need to introduce DLL, can be downloaded on the official website, can also be downloaded below

C # code

2. protected void Getexcel (DataTable dt)
4. {
6. Npoi. HSSF. Usermodel.hssfworkbook book = new Npoi. HSSF.  Usermodel.hssfworkbook ();
8. Npoi. Ss. Usermodel.sheet Sheet = Book.  Createsheet ("test_01");
10. Npoi. Ss. Usermodel.row Row = sheet. CreateRow (0);
12. For (int i = 0; i < dt. Columns.count; i++)
14. {
16. Row. Createcell (i). Setcellvalue (dt. Columns[i]. ColumnName);
18. }
22. For (int i = 0; i < dt. Rows.Count; i++)
24. {
26. Npoi. Ss. Usermodel.row row2 = sheet. CreateRow (i + 1);
28. For (int j = 0; j < dt. Columns.count; J + +)
30. Row2. Createcell (j). Setcellvalue (dt. ROWS[I][J]. ToString ());
32. }
38. //write to client
40. System.IO.MemoryStream ms = new System.IO.MemoryStream ();
42. Book. Write (MS);
44. Response.AddHeader ("Content-disposition", string. Format ("attachment;  Filename=emptyworkbook.xls "));
46. Response.BinaryWrite (Ms. ToArray ());
48. book = null;
50. Ms. Close ();
52. Ms. Dispose ();
56. }

Excel Import

C # code

2. Hssfworkbook Hssfworkbook;
4. #region
6. Public DataTable importexcelfile (string filePath)
8. {
10. #region//initialization information
14. Try
16. {
18. using (FileStream file = new FileStream (FilePath, FileMode.Open, FileAccess.Read))
20. {
22. Hssfworkbook = new Hssfworkbook (file);
24. }
26. }
28. catch (Exception e)
30. {
32. throw E;
34. }
38. #endregion
42. Npoi. Ss. Usermodel.sheet Sheet = Hssfworkbook. Getsheetat (0);
44. System.Collections.IEnumerator rows = Sheet. Getrowenumerator ();
48. DataTable dt = new DataTable ();
50. For (int j = 0; J < (sheet. GetRow (0). Lastcellnum); J + +)
52. {
54. Dt. Columns.Add (Convert.tochar (((int)' A ') + j).  ToString ());
56. }
60. While (rows. MoveNext ())
62. {
64. Hssfrow row = (hssfrow) rows. Current;
66. DataRow dr = dt. NewRow ();
70. For (int i = 0; i < row. Lastcellnum; i++)
72. {
74. Npoi. Ss. Usermodel.cell Cell = row. Getcell (i);
80. if (cell = = null)
82. {
84. Dr[i] = null;
86. }
88. Else
90. {
92. Dr[i] = cell. ToString ();
94. }
96. }
98. Dt. Rows.Add (DR);
100. }
102. return DT;
104. }
106. #endregion

This allows you to read an Excel file and return a DataTable