不调用Excel，DataTable导出Excel

  1 class ExportToExcel
  2    {
  3
  4        public void SaveExcel(DataTable dt, string Filter, string FileName, string SheetName)
  5        {
  6
  7            if (FileName == "")
  8            {
  9                SaveFileDialog a = new SaveFileDialog();
 10                a.Filter = "Excel 工作簿 (*.xls)|*.xls";
 11                if (a.ShowDialog() == DialogResult.OK)
 12                {
 13                    FileName = a.FileName;
 14                }
 15                else
 16                {
 17                    return;
 18                }
 19            }
 20
 21            try
 22            {
 23                System.IO.File.Delete(FileName);
 24            }
 25            catch (Exception)
 26            {
 27                MessageBox.Show("该文件已经存在，删除文件时出错！", "错误", MessageBoxButtons.OK, MessageBoxIcon.Error);
 28                return;
 29            }
 30
 31            string ConnStr;
 32            ConnStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=\"" + FileName + "\";Extended Properties=\"Excel 8.0;HDR=YES\"";
 33
 34            OleDbConnection conn_excel = new OleDbConnection();
 35            conn_excel.ConnectionString = ConnStr;
 36
 37            OleDbCommand cmd_excel = new OleDbCommand();
 38
 39            string sql;
 40            sql = SqlCreate(dt, SheetName);
 41
 42            conn_excel.Open();
 43            cmd_excel.Connection = conn_excel;
 44            cmd_excel.CommandText = sql;
 45            cmd_excel.ExecuteNonQuery();
 46
 47            conn_excel.Close();
 48
 49            OleDbDataAdapter da_excel = new OleDbDataAdapter("Select * From [" + SheetName + "$]", conn_excel);
 50            DataTable dt_excel = new DataTable();
 51            da_excel.Fill(dt_excel);
 52
 53            da_excel.InsertCommand = SqlInsert(SheetName, dt, conn_excel);
 54
 55            DataRow dr_excel;
 56            string ColumnName;
 57
 58            foreach (DataRow dr in dt.Select(Filter))
 59            {
 60                dr_excel = dt_excel.NewRow();
 61
 62                foreach (DataColumn dc in dt.Columns)
 63                {
 64                    ColumnName = dc.ColumnName; 
 65                    dr_excel[ColumnName] = dr[ColumnName];
 66
 67                }
 68                dt_excel.Rows.Add(dr_excel);
 69
 70            }
 71
 72            da_excel.Update(dt_excel);
 73            conn_excel.Close();
 74
 75            if (MessageBox.Show("数据成功导出到『" + FileName + "』，是否现在打开？", "导出",
 76                MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
 77            {
 78                System.Diagnostics.Process.Start(FileName);
 79            }
 80        }
 81
 82        private void CheckColumn(DataTable dt, DataTable dt_v)
 83        {
 84            foreach (DataRow dr in dt_v.Select())
 85            {
 86                if (!dt.Columns.Contains(dr["列名"].ToString()))
 87                {
 88                    dr.Delete();
 89                }
 90            }
 91            dt_v.AcceptChanges();
 92        }
 93
 94        private string GetDataType(Type i)
 95        {
 96            string s;
 97
 98            switch (i.Name)
 99            {
100                case "String":
101                    s = "Char";
102                    break;
103                case "Int32":
104                    s = "Int";
105                    break;
106                case "Int64":
107                    s = "Int";
108                    break;
109                case "Int16":
110                    s = "Int";
111                    break;
112                case "Double":
113                    s = "Double";
114                    break;
115                case "Decimal":
116                    s = "Double";
117                    break;
118                default:
119                    s = "Char";
120                    break;
121
122            }
123            return s;
124        }
125
126        private OleDbType StringToOleDbType(Type i)
127        {
128            OleDbType s;
129
130            switch (i.Name)
131            {
132                case "String":
133                    s =  OleDbType.Char;
134                    break;
135                case "Int32":
136                    s = OleDbType.Integer;
137                    break;
138                case "Int64":
139                    s = OleDbType.Integer;
140                    break;
141                case "Int16":
142                    s = OleDbType.Integer;
143                    break;
144                case "Double":
145                    s = OleDbType.Double;
146                    break;
147                case "Decimal":
148                    s = OleDbType.Decimal;
149                    break;
150                default:
151                    s = OleDbType.Char;
152                    break;
153
154            }
155            return s;
156
157        }
158
159
160        private string SqlCreate(DataTable dt, string SheetName)
161        {
162            string sql;
163
164            sql = "CREATE TABLE " + SheetName + " (";
165
166            foreach (DataColumn dc in dt.Columns)
167            {
168                sql += "[" + dc.ColumnName + "] " + GetDataType(dc.DataType) + " ,";
169            }
170            
171            //sql = "CREATE TABLE [" + SheetName + "] (";
172
173            //foreach (C1.Win.C1TrueDBGrid.C1DataColumn dc in grid.Columns)
174            //{
175            //    sql += "[" + dc.Caption + "] " + GetDataType(dc.DataType) + ",";
176            //}
177            //sql = sql.Substring(0, sql.Length - 1);
178            //sql += ")";
179            
180            sql = sql.Substring(0, sql.Length - 1);
181            sql += ")";
182
183            return sql;
184        }
185
186
187        // 生成 InsertCommand 并设置参数
188        private OleDbCommand SqlInsert(string SheetName, DataTable dt, OleDbConnection conn_excel)
189        {
190            OleDbCommand i;
191            string sql;
192
193            sql = "INSERT INTO [" + SheetName + "$] (";
194            foreach (DataColumn dc in dt.Columns)
195            {
196                sql += "[" + dc.ColumnName + "] ";
197                sql += ",";
198            }
199            sql = sql.Substring(0, sql.Length - 1);
200            sql += ") VALUES (";
201            foreach (DataColumn dc in dt.Columns)
202            {
203                sql += "?,";
204            }
205            sql = sql.Substring(0, sql.Length - 1);
206            sql += ")";
207
208            i = new OleDbCommand(sql, conn_excel);
209
210            foreach (DataColumn dc in dt.Columns)
211            {
212                i.Parameters.Add("@" + dc.Caption, StringToOleDbType(dc.DataType), 0, dc.Caption);
213            }
214
215            return i;
216        }
217   
218    }