無法將'System.Data.SqlClient.SqlConnection'類型的錯誤值轉換爲'字符串'

Question

似乎無法確定在此錯誤中使用的代碼。

它指出在此行暗淡Flag_DR作爲SqlDataReader的= Flag_com.ExecuteReader

非常感謝

  Private Sub txt_Password_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles txt_Password.KeyDown 
      If e.KeyCode = Keys.Enter Then 
      If txt_Username.Text = "hospital" And txt_Password.Text = "user" Then 
      Me.Hide() 

      Dim r0 As String 

      Dim Flag_constr As New SqlConnection("Data Source=(localdb)\Projects;Initial Catalog=MasterDB;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False") 
      'Dim Fill_Textbox_cmdstr As String = "select Regno,Name,Age,Address,Phone,Checkupdate,Checkuptime,Disease,Bloodgroup,Doctor,Remarks from clinicpatients where Regno=1" 
      Dim Flag_cmdstr As String = "select * from flag" 
      Dim Flag_con As New SqlConnection("Data Source=(localdb)\Projects;Initial Catalog=MasterDB;Integrated Security=True;Connect Timeout=30;Encrypt=False;TrustServerCertificate=False") 
      Dim Flag_com As New SqlCommand(Flag_cmdstr, Flag_con) 
      Flag_con.Open() 
      Dim Flag_DR As SqlDataReader = Flag_com.ExecuteReader 
      While Flag_DR.Read 
       r0 = Flag_DR(0) 
      End While 
      Flag_con.Close() 

      If r0 = 0 Then 
       Dim objfrmBed As New frmBed() 
       objfrmBed.Show() 
      ElseIf r0 = 1 Then 
       Dim objfrmMain As New frmMain() 
       objfrmMain.Show() 
      End If 

Answer 1

有什麼不對您的連接字符串。你是否可以改變它，如下所示，然後再試一次：

Dim Flag_con As New SqlConnection("Data Source=(localdb)\Projects;Initial Catalog=MasterDB;Integrated Security=True;Connect Timeout=30;Trusted_Connection=True;MultipleActiveResultSets=True;")