Question

我正在尝试为我的商店创建一个桌面应用程序。

我的应用程序当前正在使用AutoComplete项目，如此屏幕截图显示：

现在我想将该单元格更改为使用LIKE函数自动完成。

例如：我的项目列表包含

["book", "brush", "pen", "samsung note 1", "samsung note 2", "samsung note 3", "samsung note 4"]

当我输入＆＃34;注意＆＃34;时，自动填充功能会建议或显示一个列表供我选择该项目。

但该列表仅包含＆＃34; samsung note 1＆＃34;，＆＃34; samsung note 2＆＃34;，＆＃34; samsung note 3＆＃34;，＆＃34; samsung note 4＆＃34 ;，因为这个项目有＆＃34;注意＆＃34;。

这是我的代码，没有LIKE功能的自动填充功能

private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{    
    if (dataGridView1.CurrentCell.ColumnIndex == 0)
    {
        Connection.ConnectionClose();
        Connection.ConnectionOpen();

        //TODO fill Autocomplete list
        string queryItem = "SELECT * FROM ITEM";

        Connection.command = new OleDbCommand(queryItem, Connection.conn);
        Connection.command.CommandType = CommandType.Text;

        AutoCompleteStringCollection kode = new AutoCompleteStringCollection();
        reader = Connection.command.ExecuteReader();

        if (reader.HasRows == true)
        {
            while (reader.Read())
            {
                kode.Add(reader["code"].ToString());
            }
        }
        else
        {
            MessageBox.Show("Data not found");
        }

        reader.Close();

        //ComboBox txtBusID = e.Control as ComboBox;
        TextBox kodeTxt = e.Control as TextBox;

        if (kodeTxt != null)
        {
            kodeTxt.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
            kodeTxt.AutoCompleteCustomSource = kode;
            kodeTxt.AutoCompleteSource = AutoCompleteSource.CustomSource;
        }
    }

    e.Control.KeyPress -= new KeyPressEventHandler(AllowNumber_KeyPress);

    if (((DataGridView)sender).CurrentCell.ColumnIndex == 0) //Assuming 0 is the index of the ComboBox Column you want to show
    {
        TextBox code = e.Control as TextBox;
        code.CharacterCasing = CharacterCasing.Upper;

        if (code != null)
        {
            code.Leave -= new EventHandler(cb_IndexChanged);
            // now attach the event handler
            code.Leave += new EventHandler(cb_IndexChanged);
        }
    }
}

我希望更改自动填充功能，以便能够使用＆＃34; LIKE ＆＃34;。

在Query中使用LIKE进行更新。

 private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
    {    
        if (dataGridView1.CurrentCell.ColumnIndex == 0)
        {
            Connection.ConnectionClose();
            Connection.ConnectionOpen();
            int currentRow = dataGridView1.CurrentRow.Index;
            //TODO fill Customer list
            string queryItem = "SELECT * FROM ITEM WHERE CODE LIKE '%" + dataGridView1.Rows[currentRow].Cells[0].Value.ToString() + "%'";

            Connection.command = new OleDbCommand(queryItem, Connection.conn);
            Connection.command.CommandType = CommandType.Text;
            AutoCompleteStringCollection kode = new AutoCompleteStringCollection();
            reader = Connection.command.ExecuteReader();

            if (reader.HasRows == true)
            {
                while (reader.Read())
                {
                    kode.Add(reader["code"].ToString());
                }
            }
            else
            {
                MessageBox.Show("Data not Found");
            }
            reader.Close();
            //ComboBox txtBusID = e.Control as ComboBox;
            TextBox kodeTxt = e.Control as TextBox;
            if (kodeTxt != null)
            {
                kodeTxt.AutoCompleteMode = AutoCompleteMode.SuggestAppend;
                kodeTxt.AutoCompleteCustomSource = kode;
                kodeTxt.AutoCompleteSource = AutoCompleteSource.CustomSource;
            }

            }
}

并收到此错误

System.NullReferenceException：未将对象引用设置为实例一个对象。在 inventory.Market.SalesOrder.dataGridView1_EditingControlShowing（对象 sender，DataGridViewEditingControlShowingEventArgs e）in C：\用户\ VPC2 \文档\库存\库存\市场\ SalesOrder.cs：行 922在 System.Windows.Forms.DataGridView.OnEditingControlShowing（DataGridViewEditingControlShowingEventArgs E）

我发现错误来自dataGridView1.Rows[currentRow].Cells[0].Value.ToString()

看起来我在输入datagridview的单元格时无法获得价值。

或者在课堂private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)

时我无法获得价值

我正在努力创造这样的东西。https://www.codeproject.com/Articles/251110/AutoComplete-TextBox-with-substing-search-similar

但不是在textBox而是在datagridview的单元格中

具有自动完成LIKE的C＃datagridview单元格

0 个答案: