[英]How to change label's text depending on item selected on a combo box which is populated using SQLite?
我有一個按鈕,為TableLayoutPanel的列創建6個控件,6列是:訂單號,產品名稱( 組合框 ),當前數量( 標簽 ),購買數量,新數量和刪除行。
使用SQLite填充組合框。 對於Variants表,我有7列:[產品名稱],名稱,[序列號],[庫存現貨],[銷售前]。
我怎樣才能使“當前數量”下的標簽根據組合框中所選項目的[Stock On Hand]而變化?
在我當前的代碼中,每次我在組合框中選擇時,都會顯示“索引超出數組范圍”的錯誤。
用於創建動態組合框的代碼:
ComboBox cboItemName = new ComboBox
{
Name = "cboItemName" + rowIndex,
Dock = DockStyle.Fill,
DropDownStyle = ComboBoxStyle.DropDownList
};
cboItemName.SelectedIndexChanged += new EventHandler(cboItemName_SelectedIndexChanged);
tblOrders.Controls.Add(FillComboBox(cboItemName));
組合框的事件處理程序的代碼:
void cboItemName_SelectedIndexChanged(object sender, EventArgs e)
{
var cbo = (ComboBox)sender;
string name = cbo.Name;
string splittedString = new String(name.Where(Char.IsDigit).ToArray());;
string labelName = "lblCurrentQuantity" + splittedString;
string selectedIndex = cbo.SelectedIndex.ToString();
string selectedItem = cbo.SelectedItem.ToString();
Label tbx = tblOrders.Controls.Find(labelName, true).FirstOrDefault() as Label;
EditLabelCurrentQuantity(tbx, selectedItem);
}
最后,改變標簽文本的代碼:
private void EditLabelCurrentQuantity(Label label, string itemSelected)
{
auth = new Authentication();
auth.getConnection();
try
{
using (SQLiteConnection con = new SQLiteConnection(auth.connectionString))
{
con.Open();
SQLiteCommand cmd = new SQLiteCommand();
cmd.CommandText = @"SELECT [Stock On Hand] FROM Variants WHERE Name='" + itemSelected + "'";
cmd.Connection = con;
SQLiteDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
string name = Convert.ToString(reader["[Stock On Hand]"]);
}
con.Close();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
我終於想通了,如果有人曾經遇到過我糟糕設計的事情,我已經通過添加以下內容解決了這個問題:
string name = Convert.ToString(reader[0]);
labelCategory.Text = name;
在:
SQLiteDataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
string name = Convert.ToString(reader["[Stock On Hand]"]);
}
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