更新时如何刷新数据网格视图？来自C＃的窗口

4 回答

• 0

  当您调用 database_connect 方法时，使用 this 传递下面的表单引用，

  private void button1_Click(object sender, EventArgs e)
  {
     //Get textfield data....
  
      //If user doesn't input the item data, show the error message. Else, update to database.
      if (error == true)
      {
          error_msg_form emf = new error_msg_form();
          emf.Show();
      }
      else
      {
          //Form1 f1 = new Form1();
          database_function df = new database_function();
           df.database_connect(this, item_code_tb.Text, des_tb.Text, unit_tb.Text, Convert.ToDouble(unit_price_tb.Text));
          //f1.refresh_dataGridView();
      }
  }
  

  然后，在方法中添加参数 Form1 form1 ，如下所示，并使用相同的引用调用 form1.refresh_dataGridView() .

  public void database_connect(Form1 form1, String item_code, String des, String unit, double price)
      {
        //Form1 f1 = new Form1();
          try
          {
  
              connect.Open();
              OleDbCommand command = new OleDbCommand();
              command.Connection = connect;
              command.CommandText = "INSERT into item (item_code, description, unit, price) values ('" + item_code + "', '" + des + "', '" + unit + "', " + price + ")";
              command.ExecuteNonQuery();
  
              connect.Close();
          }
          catch(Exception e)
          {
              Debug.WriteLine(e.Source);
              connect.Close();
          }
         form1.refresh_dataGridView();
      }
  

  另外，更改以下代码以刷新数据网格视图，

  public void refresh_dataGridView()
      {
          dataGridView1.DataSource = typeof(List);
          dataGridView1.DataSource = df.get_view();
          Debug.WriteLine("refuesh");
      }
  

  回复于 2024-04-18T19:42:31+08:00
• 2

  您最好重构代码并将数据库访问代码分离到单独的类文件中 . 然后你可以从其他类，表单等调用这些函数 .

  在插入项方法之后的表单中，您可以设置gridview数据源，例如：

  database_function df = new database_function();
  df.InsertItem("sdfsdf", "Description", "KG", 5);
  //load data again
  dataGridView1.DataSource = df.get_view();
  

  你需要两个方法，一个用于插入，一个用于获取详细信息

  public class database_function
  {
       public void InsertItem(String item_code, String des, String unit, double price)
          {
             //Form1 f1 = new Form1();
              try
              {
                  connect.Open();
                  OleDbCommand command = new OleDbCommand();
                  command.Connection = connect;
                  command.CommandText = "INSERT into item (item_code, description, unit, price) values ('" + item_code + "', '" + des + "', '" + unit + "', " + price + ")";
                  command.ExecuteNonQuery();
  
                  connect.Close();
              }
              catch(Exception e)
              {
                  Debug.WriteLine(e.Source);
                  connect.Close();
              }
           //f1.refresh_dataGridView();
          }
  
   public DataTable get_view()
      {
          connect.Open();
          OleDbCommand command = new OleDbCommand();
          command.Connection = connect;
          string query = "Select item_code, description, unit, price from item";
          command.CommandText = query;
  
          OleDbDataAdapter da = new OleDbDataAdapter(command);
          DataTable dt = new DataTable();
          da.Fill(dt);
          connect.Close();
          return dt;
      }
  

  }

  回复于 2024-04-18T19:42:31+08:00
• 0

  这是我用于我的代码：

  private void Form1_Activated(object sender, EventArgs e) {
          if (GlobalVariables.bReload == false) {
              Activated -= Form1_Activated;
              GlobalVariables.bReload = true;
              dgv1.DataSource = "my datasource"
              dgv1.Refresh();
              Activated += Form1_Activated;
          }
      }
  

  在我的情况下，我想在对子窗体进行修改之后触发更新，然后返回到我的datagridview所在的主窗体 . 我使用布尔类型的全局变量来管理它 .

  回复于 2024-04-18T19:42:31+08:00
• 1

  我假设当项目已插入数据库时，您关闭“AddItem”表单 . 我建议在不传递引用的情况下更明确地通知成功插入，并通过将其公开来暴露表单的控制

  根据查询结果更改 database_connect 方法返回 true/false

  public void database_connect(String item_code, String des, String unit, double price)
  {
      try
      {
          connect.Open();
          OleDbCommand command = new OleDbCommand();
          command.Connection = connect;
          command.CommandText = "INSERT into item (item_code, description, unit, price) values ('" + item_code + "', '" + des + "', '" + unit + "', " + price + ")";
          int insertedRows = command.ExecuteNonQuery();
  
          return insertedRows > 0;
      }
      catch(Exception e)
      {
          Debug.WriteLine(e.Source);
      }
      finally
      {
          connect.Close();
      }
  
      // false will be returned if exception will be thrown
      return false;
  }
  

  然后在 AddItem 表单中将 Form.DialogResult 属性设置为 Ok 如果已成功添加项目 .

  public class AddNewItemForm : Form
  {
      private void button1_Click(object sender, EventArgs e)
      {
          if (error == true)
          {
              error_msg_form emf = new error_msg_form();
              emf.Show();
          }
          else
          {
              database_function df = new database_function();
              bool isAdded = df.database_connect(item_code_tb.Text,
                                                 des_tb.Text, 
                                                 unit_tb.Text,
                                                 Convert.ToDouble(unit_price_tb.Text));
  
              if(isAdded)
              {
                  this.DialogResult = DialogResult.Ok;
              }
          }
      }             
  }
  

  然后在Main表单中使用 ShowDialog 方法获取有关成功插入的结果 .

  public class MainForm: Form
  {
      private void ButtonAddItem_Click(object sender, EventArgs e)
      {
          using(var addItemForm = new AddNewItemForm())
          {
              if(addItemForm.ShowDialog() == DialogResult.Ok)
              {
                  // here you can update your DataGridView
                  this.DataGridView.DataSource = df.get_view();
              }
          }
      }           
  }
  

  回复于 2024-04-18T19:42:31+08:00