試圖爲文件D：\ Stra.mdf附加一個自動命名的數據庫失敗

Question

我們正在創建一個項目。執行時，我們得到這個錯誤。我們有註冊頁面，在這裏我們點擊註冊，領取this錯誤

Answer 1

private void button1_Click(object sender, EventArgs e) 
     { 
      string Constring = ConnectionString.Constring; 
      SqlConnection con = new SqlConnection(Constring); 
      con.Open(); 
      SqlCommand cmd = new SqlCommand("select usname,pwd from regis where usname='" + textBox1.Text + "'", con); 
      SqlDataReader dr; 
      dr = cmd.ExecuteReader(); 
      while (dr.Read()) 
      { 
       usname = dr["usname"].ToString(); 
       pwd = dr["pwd"].ToString(); 
      } 
         dr.Close(); 
      con.Close(); 
      if (textBox1.Text == usname && textBox2.Text == pwd) 
      { 
       this.Hide(); 
       UserHome us = new UserHome(textBox1.Text); 
       us.Show(); 
      } 
      else 
      { 
       MessageBox.Show("Invalid USername or Password"); 
      } 

     }