Asp.net 如何减少多次尝试捕获

嗨，我是一个开发项目的初学者，在我的项目中我使用了try-catch和try-catch，所以我如何专业地编写查询

我的代码是

try
    {
        //connection();
        con = new SqlConnection(constr);
        con.Open();
        txtcusname.Text = "";
        txtcusnumber.Text = "";
        query = "sample_SP";
        cmd = new SqlCommand(query, con);
        cmd.CommandType = CommandType.StoredProcedure;
        cmd.Parameters.AddWithValue("@GetCusID", txtcusid.Text).ToString();
        da = new SqlDataAdapter(cmd);
        ds = new DataSet();
        da.Fill(ds);
        GrdCustomerDetails.DataSource = ds;
        GrdCustomerDetails.DataBind();
        con.Close();
        try
        {
            //connection();
            con = new SqlConnection(constr);
            con.Open();
            ViewState["VSCusID"] = txtcusid.Text;
            cmd = new SqlCommand("select contname,mob from CustContacts_TB where cid='" + ViewState["VSCusID"] + " '", con);
            dr = cmd.ExecuteReader();
            dr.Read();
            txtcusname.Text = dr["contname"].ToString();
            txtcusnumber.Text=dr["mob"].ToString();
            con.Close();
        }
        catch(Exception ex)
        {

        }
        finally
        {
            //connection();
            con = new SqlConnection(constr);
            con.Open();
            ViewState["VSCusID"] = txtcusid.Text;
            //cmd = new SqlCommand("select compname from CustCreate_TB inner join CustContacts_TB on CustContacts_TB.'" + ViewState["VSCusID"] + "'=CustCreate_TB.'" + ViewState["VSCusID"] + "' ", con);
            cmd = new SqlCommand("select compname from CustCreate_TB where cid='" + ViewState["VSCusID"] + " ' ", con);
            dr = cmd.ExecuteReader();
            dr.Read();
            txtcompname.Text = dr["compname"].ToString();
            con.Close();
            //txtcusname.DataBind();
        }
    }
    catch (Exception ex)
    { 

    }
    finally
    {
        //connection();
        con = new SqlConnection(constr);
        con.Open();
        cmd = new SqlCommand("select compliantID,priorty,status from NewComp1 where customerid='" + ViewState["VSCusID"] + "' and status='open'", con);
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataSet ds = new DataSet();
        da.Fill(ds);
        grdpending.DataSource = ds;
        grdpending.DataBind();

        cmd = new SqlCommand("select compliantID,priorty,status from NewComp1 where customerid='" + ViewState["VSCusID"] + "' and status='closed'", con);
        da = new SqlDataAdapter(cmd);
        ds = new DataSet();
        da.Fill(ds);
        grdClosed.DataSource = ds;
        grdClosed.DataBind();
        con.Close();
    }

它可以减少代码和它的正确格式。。。。感谢您的帮助，这对培养我的编码技能很有帮助

您基本上具备：

try
    {        
        [block1]
        try
        {
            [block2]
        }
        catch(Exception ex)
        {

        }
        finally
        {
            [block3]
        }
    }
    catch (Exception ex)
    { 

    }
    finally
    {
        [block4]
    }
  }

它们似乎都在获取数据并填充控件或变量。您没有指定在异常中要执行的操作，因此您可以简单地将它们全部放在单个try块中，或者将它们全部放在单个块中。我不明白为什么它们必须嵌套。 Finally通常用于“清理”操作，如处理打开的连接，但您似乎将Finally用于新的选择和填充操作，这是错误的

因此：

或者，您是否需要知道某个特定块何时失败，但每个块都在try/catch中

try
  {        
        [block1]                 
  }
  ...
try
  {        
        [block4]                 
  }

---

你为什么要建立这样的联系

你可以这样做

try {
using (System.Data.SqlClient.SqlConnection cnn = new System.Data.SqlClient.SqlConnection()) {
    if (cnn.State == ConnectionState.Closed)
        cnn.Open();
    using (System.Data.SqlClient.SqlCommand cmd = new System.Data.SqlClient.SqlCommand()) {
        //first task
    }
    using (System.Data.SqlClient.SqlCommand cmd1 = new System.Data.SqlClient.SqlCommand()) {
        //second one
    }
    using (System.Data.SqlClient.SqlCommand cdm2 = new System.Data.SqlClient.SqlCommand()) {
        //third task
    }

}
} catch (SqlClient.SqlException sqlex) {
//catch exception sql
//to do
} catch (Exception ex) {
//generic exceptio
//to do some stuff
} finally {
//if need to do later
}

---

这很容易——去掉所有的try/catch块。您不明白异常处理是关于什么的

try {
using (System.Data.SqlClient.SqlConnection cnn = new System.Data.SqlClient.SqlConnection()) {
    if (cnn.State == ConnectionState.Closed)
        cnn.Open();
    using (System.Data.SqlClient.SqlCommand cmd = new System.Data.SqlClient.SqlCommand()) {
        //first task
    }
    using (System.Data.SqlClient.SqlCommand cmd1 = new System.Data.SqlClient.SqlCommand()) {
        //second one
    }
    using (System.Data.SqlClient.SqlCommand cdm2 = new System.Data.SqlClient.SqlCommand()) {
        //third task
    }

}
} catch (SqlClient.SqlException sqlex) {
//catch exception sql
//to do
} catch (Exception ex) {
//generic exceptio
//to do some stuff
} finally {
//if need to do later
}