那就看看我做的,建立一个mutua类文件,在里面写代码
namespace *******
{
class mutua
{
public static SqlConnection conn = null;
public DataSet ds = null;
public SqlDataAdapter sda = null;
public String ExceptionStr = "";
public void Openlink()
{
conn = new SqlConnection();
conn.ConnectionString = "Server=192.168.1.240;uid=sa;pwd=chaimisin8712*;database=GZ_DATA";
try
{
conn.Open();
}
catch
{
conn.Close();
}
}
public void linkSQL(String sql)
{
if (conn != null)
{
ds = new DataSet();
sda = new SqlDataAdapter();
sda.SelectCommand = new SqlCommand(sql, conn);
SqlCommandBuilder builder = new SqlCommandBuilder(sda);
sda.Fill(ds);
}
}
}
}
启动窗体初始化时就openlink打开链接,后面应用到窗体使用treeview就写这样的代码
void getView()
{
mutua s = new mutua();
mutua d = new mutua();
mutua e = new mutua();
s.linkSQL("Select Distinct bm from a_gydy order by bm");
if (s.ds != null)
{
for (int i = 0; i < s.ds.Tables[0].Rows.Count; i++)
{
treeView1.Nodes.Add(s.ds.Tables[0].Rows[i][0].ToString());
d.linkSQL("Select Distinct gy from a_gydy where bm='" + s.dss.Tables[0].Rows[i][0].ToString() + "' order by gy");
if (d.ds != null)
{
for (int j = 0; j < d.ds.Tables[0].Rows.Count; j++)
{
treeView1.Nodes[i].Nodes.Add(d.ds.Tables[0].Rows[j][0].ToString());
d.linkSQL("Select Distinct gw from c_gy where bm='" + s.ds.Tables[0].Rows[i][0].ToString() + "' and gy='" + d.ds.Tables[0].Rows[j][0].ToString() + "' and gw<>'' order by gw");
if (e.ds != null)
{
for (int k = 0; k < e.ds.Tables[0].Rows.Count; k++)
{
treeView1.Nodes[i].Nodes[j].Nodes.Add(e.ds.Tables[0].Rows[k][0].ToString());
}
}
}
}
}
}
给treeView1加了三级目录
那挨接