添加控制動態表格是從FlowLayoutPanel的

Question

不同當窗體上動態地添加用戶控件我有一個正確的輸出中

using (SqlConnection myDatabaseConnection = new SqlConnection(myConnectionString.ConnectionString)) 
     { 
      myDatabaseConnection.Open(); 
      using (SqlCommand SqlCommand = new SqlCommand("Select LastName from Employee", myDatabaseConnection)) 
      using (SqlDataAdapter da = new SqlDataAdapter(SqlCommand)) 
      { 

       SqlDataReader DR1 = SqlCommand.ExecuteReader(); 
       int y = 0; 
       while (DR1.Read()) 
       { 
        y++; 
        for (int i = 0; i < y; i++) 
        { 
         UserControl2 userconrol = new UserControl2(); 
         userconrol.Location = new Point(50, 30 * i); 
         userconrol.Tag = i; 
         userconrol.LastName = (string)DR1["LastName"]; 
         this.Controls.Add(userconrol); 
        } 
       } 
      } 
     } 

但是當我使用FlowLayoutPanel中添加控件動態，這是發生了什麼：

using (SqlConnection myDatabaseConnection = new SqlConnection(myConnectionString.ConnectionString)) 
     { 
      myDatabaseConnection.Open(); 
      using (SqlCommand SqlCommand = new SqlCommand("Select LastName from Employee", myDatabaseConnection)) 
      using (SqlDataAdapter da = new SqlDataAdapter(SqlCommand)) 
      { 

       SqlDataReader DR1 = SqlCommand.ExecuteReader(); 
       int y = 0; 
       while (DR1.Read()) 
       { 
        y++; 
        for (int i = 0; i < y; i++) 
        { 
         UserControl2 userconrol = new UserControl2(); 
         userconrol.Tag = i; 
         userconrol.LastName = (string)DR1["LastName"]; 
         flowLayoutPanel1.Controls.Add(userconrol); 
        } 
       } 
      } 
     } 

問題是什麼？我使用相同的循環爲什麼當我使用flowlayoutpanel動態添加控件時，它不顯示相同的輸出？

Answer 1

將您的FlowLayoutPanel的FlowDirection()更改爲TopDown。

編輯：

而且，擺脫了對環......那是什麼應該做的事情？

也許有點像？

using (SqlConnection myDatabaseConnection = new SqlConnection(myConnectionString.ConnectionString)) 
    { 
     myDatabaseConnection.Open(); 
     using (SqlCommand SqlCommand = new SqlCommand("Select LastName from Student", myDatabaseConnection)) 
     using (SqlDataAdapter da = new SqlDataAdapter(SqlCommand)) 
     { 
      int i = 0; 
      SqlDataReader DR1 = SqlCommand.ExecuteReader(); 
      while (DR1.Read()) 
      { 
       i++; 
       UserControl2 userconrol = new UserControl2(); 
       userconrol.Tag = i; 
       userconrol.LastName = (string)DR1["LastName"]; 
       flowLayoutPanel1.Controls.Add(userconrol); 
      } 
     } 
    } 

Answer 2

using (SqlConnection myDatabaseConnection = new SqlConnection(myConnectionString.ConnectionString)) 
     { 
      myDatabaseConnection.Open(); 
      using (SqlCommand SqlCommand = new SqlCommand("Select LastName from Employee", myDatabaseConnection)) 
      using (SqlDataAdapter da = new SqlDataAdapter(SqlCommand)) 
      { 
       List<string> list1 = new List<string>(); 
       SqlDataReader DR1 = SqlCommand.ExecuteReader(); 
       while (DR1.Read()) 
       { 
        list1.Add((string)DR1["LastName"]); 
       } 

       int i = 0; 
       foreach (string LastName in list1) 
       { 
        i++; 
        UserControl2 userconrol = new UserControl2(); 
        userconrol.Tag = i; 
        userconrol.LastName = LastName; 
        flowLayoutPanel1.Controls.Add(userconrol); 
       } 
      } 
     }