C#,winform形式下 2個combobox 互相聯動---資料庫access
參考文章：
privatevoid Form1_Load(object sender, EventArgs e)
{
SqlConnection con =new SqlConnection(conn);
con.Open();
SqlCommand cmd =new SqlCommand("select * from department",con);
SqlDataAdapter sda =new SqlDataAdapter(cmd);
DataTable dt
sda.Fill(dt);
con.Close();
comboBox1.DataSource = dt;
comboBox1.DisplayMember ="department";
comboBox1.ValueMember ="departmentId";
}
privatevoid comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
{
DataRowView drv = (DataRowView)comboBox1.SelectedItem;
int id = Convert.ToInt32(drv.Row["departmentId"].ToString());
SqlConnection con =new SqlConnection(conn);
con.Open();
SqlCommand cmd
SqlDataAdapter sda =new SqlDataAdapter(cmd);
DataTable dt =new DataTable();
sda.Fill(dt);
comboBox2.DataSource = dt;
comboBox2.DisplayMember ="major";
comboBox2.ValueMember ="majorId";
}
2，
ComboBox的SelectionChangeCommitted事件
實現方案：
在ComboBox的SelectionChangeCommitted事件 寫 聯動取數：
private void comBox_subject_SelectionChangeCommitted(object sender, System.EventArgs e)
{
if (comBox_subject.SelectedIndex > -1)
{
DataRowView drv = (DataRowView)comBox_subject.SelectedItem;
String check_subject = drv.Row["學科"].ToString();
string connectionStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + System.Windows.Forms.Application.StartupPath + "/teachdb.mdb";
OleDbConnection conn = new OleDbConnection(connectionStr);
conn.Open();
string strsubject = "select distinct 出版社 from presstable where 學科='" + check_subject + "'";
OleDbDataAdapter MyAdapter1 = new OleDbDataAdapter(strsubject, conn);
DataSet ds = new DataSet();
MyAdapter1.Fill(ds, "press");
comBox_Press.DataSource = ds.Tables["press"].DefaultView;
comBox_Press.DisplayMember = "出版社";
comBox_Press.ValueMember = "出版社";
conn.Close();
}
}
3
今天工作中遇到一個頭疼到問題就是兩個comboBox互相聯動繫結，開始用comboBox1_SelectedIndexChanged事件，結果兩個comboBox不停的相互繫結，死迴圈了
後來發現微軟還提供了一個comboBox1_DropDownClosed事件：當關閉組合框下拉部分時發生，當用程式改變SelectedIndex時就不會出現兩個comboBox相互改對方到Index並觸發comboBox1_SelectedIndexChanged，
後來將SelectedIndexChanged事件全部換成DropDownClosed，就可以實現兩個comboBox互相聯動了；
TextChanged事件和TextUpdate也是一個對用程式改變其值敏感，一個不敏感。