DatagridView 常用功能代码

1.DatagridView自动编号

代码

  private   void  dataGridView1_RowPostPaint( object  sender, DataGridViewRowPostPaintEventArgs e)
        {
                // 自动编号与数据库无关
            Rectangle rectangle  =   new  Rectangle(e.RowBounds.Location.X, e.RowBounds.Location.Y, dataGridView1.RowHeadersWidth  -   4 ,e.RowBounds.Height);
            TextRenderer.DrawText(e.Graphics, (e.RowIndex  +   1 ).ToString(), dataGridView1.RowHeadersDefaultCellStyle.Font, rectangle,
            dataGridView1.RowHeadersDefaultCellStyle.ForeColor, TextFormatFlags.VerticalCenter  |  TextFormatFlags.Right);

        }

2.DatagridView 导出数据到Excel

代码

private   void  btnExport_Click( object  sender, EventArgs e)
        {
             if  ( this .openFileDialog1.FileNames.Length  ==   0 )
            {
                MessageBox.Show( " 请先选择数据源! " );
                 return ;
            }
            
            saveFileDialog.Filter  =   " Execl files (*.xls)|*.xls " ;
            saveFileDialog.FileName  =   " mydata " ;

            saveFileDialog.FilterIndex  =   0 ;

            saveFileDialog.RestoreDirectory  =   true ;

            saveFileDialog.CreatePrompt  =   true ;

            saveFileDialog.Title  =   " Export Excel File To " ;
            saveFileDialog.ShowDialog();
            Stream myStream;

             try
            {
                myStream  =  saveFileDialog.OpenFile();
            }
             catch
            {
                 return ;
            }
             // StreamWriter sw = new StreamWriter(myStream, System.Text.Encoding.GetEncoding("gb2312"));
            StreamWriter sw  =   new  StreamWriter(myStream, System.Text.Encoding.GetEncoding( - 0 ));
             string  str  =   "" ;
             try
            {
                 // 写标题
                 for  ( int  i  =   0 ; i  <  dataGridView1.ColumnCount; i ++ )
                {
                     if  (i  >   0 )
                    {
                        str  +=   " \t " ;
                    }
                    str  +=  dataGridView1.Columns[i].HeaderText;

                }
                sw.WriteLine(str);
                 // 写内容

                 for  ( int  j  =   0 ; j  <  dataGridView1.Rows.Count; j ++ )
                {
                     string  tempStr  =   "" ;

                     for  ( int  k  =   0 ; k  <  dataGridView1.Columns.Count; k ++ )
                    {
                         if  (k  >   0 )
                        {
                            tempStr  +=   " \t " ;
                        }

                        tempStr  +=  dataGridView1.Rows[j].Cells[k].Value.ToString();

                    }
                    sw.WriteLine(tempStr);

                }
                sw.Close();
                myStream.Close();

            }

             catch  (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }

             finally
            {
                sw.Close();
                myStream.Close();
            }
        }

 3.DataGridView格式化日期

代码

    private   void  dataGridView1_CellFormatting( object  sender, DataGridViewCellFormattingEventArgs e)
        {

             if  (e.ColumnIndex  ==  dataGridView1.Columns[ " PriceDateTime " ].Index)
            {
                 if  (e.Value  !=   null )
                {
                    e.Value  =  Convert.ToDateTime(e.Value).ToString( " yyyy年MM月dd日 hh时mm分 " );
                }
            }
        }

 4.OpenFileDialog 打开多文件（记得将MultiSelect 这个属性改为True)

   this .openFileDialog1.Filter  =   " mydata.dat|*.dat " ;
   this .openFileDialog1.FileName  =   "" ;
   this .openFileDialog1.ShowDialog();
   string [] filenames  =   this .openFileDialog1.FileNames;