如何在单击事件按钮上使用数据库记录填充列表视图 [英] How to populate list view with database records on click event button

问题描述

我正在尝试在列表视图上显示一组数据库记录，但是由于某种原因，我会收到此错误对象引用未设置为对象的实例.
基本上在我的数据库表上，我有服务器记录，并且分类如下:

我的数据库表称为Food，该表的属性为FoodName&. FoodType.
FoodType字段上的记录分为以下类别:

-入门-这是10条记录
-主要-这是12条记录
-Dessert-这是10条记录

现在我想要的是，当我单击启动程序"按钮时，我想在我的列表视图中显示FoodType启动程序"的10条记录的FoodName.
到目前为止，我已经设法在启动程序"单击事件按钮下执行了此操作(请参见下面的代码)，但是由于某种原因，我遇到了错误.

I''m trying to display a set of database records on my listview, but for some reason I get this error Object reference not set to an instance of an object.
Basically on my database table I have serveral records and thay are categorised for instance:

My database table is called Food and the attributes of this table are FoodName & FoodType.
The records on the FoodType field are categorised such as:

-Starter - here are 10 records
-Main - here are 12 records
-Dessert - here are 10 records

Now what I want is that when I click the Starter Button I want to display on my listview the FoodName of 10 records of the FoodType ''Starter''.
So far I have managed to do this under my Starter click event button (see the code below) but for some reason i get an error.

private void cmdStarters_Click(object sender, EventArgs e)
{
   OleDbConnectionStringBuilder connBuilder = new OleDbConnectionStringBuilder();
   connBuilder.DataSource = @"C:\Users\AP_AE\Desktop\DTPOS_APP\DataBase\DtposMenu.accdb";
   connBuilder.Provider = "Microsoft.ACE.OLEDB.12.0";
   connBuilder.Add("Jet OLEDB:Engine Type", "5");
  
   string foodTypeSql = @"SELECT FoodName, FoodType FROM Food WHERE FoodType = @foodType";
   using (OleDbConnection conn = new OleDbConnection(connBuilder.ConnectionString))
   {
      try
      {
         conn.Open();
        
         OleDbCommand foodsCommand = new OleDbCommand(foodTypeSql, conn);
         OleDbParameter foodType = foodsCommand.Parameters.Add("@foodType", OleDbType.VarChar, 15);
         OleDbDataAdapter foodsDa = new OleDbDataAdapter(foodsCommand);
                   
         foodType.Value = "Starter";
         foodsDa.Fill(DtposMenuDS, "Starter");

         starterTable = DtposMenuDS.Tables["Food"];

         ListViewItem foodItem = new ListViewItem(((DataRowView)DtposMenuBS.Current)["FoodName"].ToString());
         this.listViewItemsInStock.Items.Add(foodItem);
      }
      catch (Exception ex)
      {
         MessageBox.Show("Error: " + ex);
      }
   }
}

谁能告诉我如何解决此问题


在此先感谢


roni

could anyone tell how to fix this problem please


thanks in advance


roni

推荐答案

//将数据从数据集中加载到ListView
私有void LoadList()
{
//从数据集中获取表
DataTable dtable = _DataSet.Tables ["Titles"];
//清除ListView控件
listView1.Items.Clear();
//在ListView控件中显示项目
for(int i = 0; i< dtable.Rows.Count; i ++)
{
DataRow drow = dtable.Rows [i];
//只有未删除的行
如果(drow.RowState！= DataRowState.Deleted)
{
//定义列表项
ListViewItem lvi =新的ListViewItem(drow ["title"].ToString());
lvi.SubItems.Add(drow ["title_id"].ToString());
lvi.SubItems.Add(drow ["price"].ToString());
lvi.SubItems.Add(drow ["pubdate"].ToString());
//将列表项添加到ListView
listView1.Items.Add(lvi);
}
}
}


请投票给我，如果它正在工作... plz :)

使用这种类型的代码....循环遍历数据集的数据表，并将每个项目添加到列表中.
提供反馈意见.

// Load Data from the DataSet into the ListView
private void LoadList()
{
// Get the table from the data set
DataTable dtable = _DataSet.Tables["Titles"];
// Clear the ListView control
listView1.Items.Clear();
// Display items in the ListView control
for (int i = 0; i < dtable.Rows.Count; i++)
{
DataRow drow = dtable.Rows[i];
// Only row that have not been deleted
if (drow.RowState != DataRowState.Deleted)
{
// Define the list items
ListViewItem lvi = new ListViewItem(drow["title"].ToString());
lvi.SubItems.Add (drow["title_id"].ToString());
lvi.SubItems.Add (drow["price"].ToString());
lvi.SubItems.Add (drow["pubdate"].ToString());
// Add the list items to the ListView
listView1.Items.Add(lvi);
}
}
}


Please vote me if it''s working...plz :)

use this type of code ....loop through the datatable of dataset and add each items into list..

give feedback if working..

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