從數據集中獲取值並將其傳遞給全局C＃

Question

我想從數據庫的數據集中獲取值。我創建了一個登錄表單，當我登錄時，它會向我顯示用戶的ID號和MessageBox中的用戶名。

當我嘗試將ID值傳遞給Globals變量時，我得到0.我正在使用for-loop和while循環。每當我將該值傳遞給另一個表單時，我仍然得到0.我不知道我的代碼中存在什麼問題。

請你指點我正確的方向？

int i ; 
HabibisGrll.Globals.cashier = i; 

private void but_log_in_Click(object sender, EventArgs e) 
     { 

      if (tbx_username.Text == "" || Tbx_Password.Text == "") 
      { 
       MessageBox.Show("Please provide UserName and Password"); 
       return; 
      } 
      try 
      { 
       //Create SqlConnection 
       using (SqlConnection con = new SqlConnection(connectionString)) 
       using (SqlCommand cmd = new SqlCommand("Select * from Tbl_Cashier where FName=@username and Password=@password", con)) 
       using (SqlDataAdapter adapt = new SqlDataAdapter(cmd)) 

       { 
        con.Open(); 
        cmd.Parameters.AddWithValue("@username", tbx_username.Text); 
        cmd.Parameters.AddWithValue("@password", Tbx_Password.Text); 

        HabibisGrll.Globals.sss = tbx_username.Text; 

        DataSet ds = new DataSet(); 
        adapt.Fill(ds); 
        con.Close(); 
        int count = ds.Tables[0].Rows.Count; 


        //while(i <= ds.Tables[0].Rows.Count - 1) 
        //{ 
        // MessageBox.Show("ID Number : " + ds.Tables[0].Rows[i].ItemArray[0] + Environment.NewLine + "USER : " + ds.Tables[0].Rows[i].ItemArray[1], "User INFO", MessageBoxButtons.OK, MessageBoxIcon.Information); 

        // i++; 
        //} 

        for (i = 0; i <= ds.Tables[0].Rows.Count - 1; i++) 
        { 
         MessageBox.Show("ID Number : " + ds.Tables[0].Rows[i].ItemArray[0] + Environment.NewLine + "USER : " + ds.Tables[0].Rows[i].ItemArray[1], "User INFO", MessageBoxButtons.OK, MessageBoxIcon.Information); 
        } 

        //If count is equal to 1, than show frmMain form 
        if (count == 1) 
        { 
         this.Hide(); 
         HabibisGrll fm = new HabibisGrll(); 
         fm.Show(); 
        } 
        else 
        { 
         MessageBox.Show("Login Failed!"); 
        } 
       } 
      } 
      catch (Exception ex) 
      { 
       MessageBox.Show(ex.Message); 
      } 
     } 

Answer 1

有幾件事情錯在這裏，例如，它是您正在使用一個for循環，當它真的只有1的記錄，但無論如何，繼承人什麼，我認爲你應該做的，改變至少可能有點陌生代碼：

private void but_log_in_Click(object sender, EventArgs e) 
{ 

    if (tbx_username.Text == "" || Tbx_Password.Text == "") 
    { 
     MessageBox.Show("Please provide UserName and Password"); 
     return; 
    } 
    try 
    { 
     //Create SqlConnection 
     using (SqlConnection con = new SqlConnection(connectionString)) 
     using (SqlCommand cmd = new SqlCommand("Select * from Tbl_Cashier where FName=@username and Password=@password", con)) 
     using (SqlDataAdapter adapt = new SqlDataAdapter(cmd)) 

     { 
      con.Open(); 
      cmd.Parameters.AddWithValue("@username", tbx_username.Text); 
      cmd.Parameters.AddWithValue("@password", Tbx_Password.Text); 

      HabibisGrll.Globals.sss = tbx_username.Text; 

      DataSet ds = new DataSet(); 
      adapt.Fill(ds); 
      con.Close(); 
      int count = ds.Tables[0].Rows.Count; 

      //If count is equal to 1, than show frmMain form 
      if (count == 1) 
      { 
       HabibisGrll.Globals.cashier = Int32.Parse(ds.Tables[0].Rows[0].ItemArray[0].ToString()); 
       MessageBox.Show("ID Number : " + ds.Tables[0].Rows[0].ItemArray[0] + Environment.NewLine + "USER : " + ds.Tables[0].Rows[0].ItemArray[1], "User INFO", MessageBoxButtons.OK, MessageBoxIcon.Information); 
       this.Hide(); 
       HabibisGrll fm = new HabibisGrll(); 
       fm.Show(); 
      } 
      else 
      { 
       MessageBox.Show("Login Failed!"); 
      } 
     } 
    } 
    catch (Exception ex) 
    { 
     MessageBox.Show(ex.Message); 
    } 
}