comboBox的联动问题,C#
表:Province:PID ,PName;
City:CID ,CName ,PID
目的:Combobox1显示PName字段,随其字段的变换,Combobox2中显示相应的城市CName。调试的时候两个combobox都没有数据的。。。请高手帮看看。。。
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS;AttachDbFilename=E:\\系统开发\\diquguanli\\diqu.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True;");
SqlDataAdapter da = new SqlDataAdapter("select PID, Pname from Province", con);
DataSet ds = new DataSet();
da.Fill(ds, " Province ");
DataTable dtGroup = ds.Tables["Province "];
comboBox1.DataSource = dtGroup;
comboBox1.DisplayMember = " PName";
comboBox1.ValueMember = " PID";
}
private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
{
if (comboBox1.SelectedIndex > -1)
{
DataRowView drv = (DataRowView)comboBox1.SelectedItem;
string pId = drv.Row["PID"].ToString();
SqlConnection con = new SqlConnection("Data Source=.\\SQLEXPRESS;AttachDbFilename=E:\\系统开发\\diquguanli\\diqu.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True;");
SqlDataAdapter da = new SqlDataAdapter("select CID, CName from City where PID='" + pId + "'", con);
DataSet ds = new DataSet();
da.Fill(ds, "City");
DataTable dtUser = ds.Tables["City"];
comboBox2.DataSource = dtUser;
comboBox2.DisplayMember = "CName";
comboBox2.ValueMember = "CID";
}
}
}