组合框项目选择更改时重新加载 DataGridview

Question

我创建了一个具有 DataGrid 的表单，它是从 excel 文件加载的。我想在组合框中显示 excel 文件表名称。我找到了在我的组合框中显示 excel 工作表名称的解决方案。但是我希望当我更改我的组合框项目时，datagridview 填充取决于我更改我的组合框的 excel 表。 [IMG]http://i67.tinypic.com/153l82v.jpg[/IMG] 我怎样才能做到这一点？ 我的代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.OleDb;
using System.IO;
namespace excel2access
{
    public partial class Form2 : Form
    {
        string FilePath;
        string CB;

        public Form2()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            OpenFileDialog OpenFD = new OpenFileDialog();
            OpenFD.FileName = "";
            OpenFD.Title = "Choose Excel file to Upload Data ";
            OpenFD.DefaultExt = "xls";
            OpenFD.Filter = "Ms-Excel Files (*.xls)|*.xls|All Files|*.*";

            if (OpenFD.ShowDialog() == DialogResult.OK)
            {
                FilePath = OpenFD.InitialDirectory + OpenFD.FileName;//Code to get FullPath, Filename and extension
                textBox1.Text = FilePath;
                string excelConnStr = string.Empty;
                OleDbCommand excelCommand = new OleDbCommand();
                if (FilePath.EndsWith(".xlsx"))
                {
                    //2007 Format
                    excelConnStr =string.Format("Provider=Microsoft.ACE.OLEDB.12.0; Data Source={0};Extended Properties='Excel 8.0;HDR=No'", FilePath);
                }
                else
                {
                    //2003 Format
                   excelConnStr= string.Format("Provider=Microsoft.Jet.OLEDB.4.0; Data Source={0};Extended Properties='Excel 8.0;HDR=No'", FilePath);
                }
                //Get the Sheets in Excel Workbook                
                OleDbConnection excelConn = new OleDbConnection(excelConnStr);
                OleDbCommand cmdExcel = new OleDbCommand();
                OleDbDataAdapter oda = new OleDbDataAdapter();
                cmdExcel.Connection = excelConn;
                excelConn.Open();
                comboBox1.DataSource = excelConn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
                comboBox1.DisplayMember = "TABLE_NAME";
                comboBox1.ValueMember = "TABLE_NAME";
                CB = comboBox1.DisplayMember;
                DataTable dtsheet = new DataTable();
                dtsheet = excelConn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);                
                OleDbDataAdapter da = new OleDbDataAdapter("select * from [" + comboBox1.Text + "]", excelConnStr);
                DataTable dt = new DataTable();
                da.Fill(dt);
                dataGridView1.DataSource = dt;
            }
        }

    }
}

Answer 1

您必须为 comboBox1 定义 SelectionIndexChanged 事件并从该事件重新绑定网格。

我必须建议您第一次加载网格时，然后将多个工作表数据存储在一个具有多个表的数据集中。

当用户更改下拉值然后从该数据集中获取数据时，您可以防止多个数据库命中。

Answer 2

试试这个

 private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            button1.PerformClick();
        }

Answer 3

您必须为 comboBox1 定义 SelectionChanged 事件并从该事件重新绑定网格。代码将是这样的：

private void comboBox1_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
     string excelConnStr = string.Empty;
     OleDbCommand excelCommand = new OleDbCommand();
     if (FilePath.EndsWith(".xlsx"))
     {
         excelConnStr =string.Format("Provider=Microsoft.ACE.OLEDB.12.0; Data Source={0};Extended Properties='Excel 8.0;HDR=No'", FilePath);
     }
     else
     {
         excelConnStr= string.Format("Provider=Microsoft.Jet.OLEDB.4.0; Data Source={0};Extended Properties='Excel 8.0;HDR=No'", FilePath);
     }
     string selectedSheet= (sender as ComboBox).SelectedItem as string;
     OleDbConnection excelConn = new OleDbConnection(excelConnStr);
     OleDbCommand cmdExcel = new OleDbCommand();
     OleDbDataAdapter oda = new OleDbDataAdapter();
     cmdExcel.Connection = excelConn;
     excelConn.Open();
     DataTable dtsheet = new DataTable();
     dtsheet = excelConn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);                
     OleDbDataAdapter da = new OleDbDataAdapter("select * from [" + selectedSheet + "]", excelConnStr);
     DataTable dt = new DataTable();
     da.Fill(dt);
     dataGridView1.DataSource = dt;
}

在上面的代码中(sender as ComboBox).SelectedItem as string; 将帮助您从选择更改事件中获取组合框中的选定项