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我正在编写一个程序，该程序允许用户使用客户名称搜索客户订单，用户在 a 中输入名称，TextBox搜索结果显示在ListBox控件中，用户必须从列表框中选择名称和客户的订单显示在一个DataGridView问题是，一旦客户单击搜索按钮，SelectedIndex更改的事件就会触发并导致程序崩溃。

private void btnSearch_Click(object sender, EventArgs e)
{
   string Query = "SELECT  CustomerID, CompanyName FROM Customers WHERE (CompanyName ”+                “LIKE'%"+ txtSearch.Text + "%')";
   clsDataTools.cmdComand = clsDataTools.con.CreateCommand();
   clsDataTools.cmdComand.CommandText = Query;

   clsDataTools.dtaDataAdapter = new SqlDataAdapter();
   clsDataTools.dtaDataAdapter.SelectCommand = clsDataTools.cmdComand;
   dsOrdersByCusName = new DataSet();
   clsDataTools.con.Close();
   clsDataTools.con.Open();
   clsDataTools.dtaDataAdapter.Fill(dsOrdersByCusName);
   clsDataTools.con.Close();
   dsOrdersByCusName.Tables[0].TableName = "OrderBCusName";

   lstResults.DataSource = dsOrdersByCusName.Tables[0];

   lstResults.DisplayMember = "CompanyName";
   lstResults.ValueMember = "CustomerID";
}

private void lstResults_SelectedIndexChanged(object sender, EventArgs d)
{
    string Query = "SELECT  * From Orders WHERE CustometID  = '" 
                   + lstResults.SelectedValue  
                   + "'";

    dataGridDataSet = new DataSet();
    clsDataTools.dtaDataAdapter = new SqlDataAdapter();
    clsDataTools.cmdComand = clsDataTools.con.CreateCommand();
    clsDataTools.cmdComand.CommandText = Query;
    clsDataTools.con.Close();
    clsDataTools.con.Open();
    clsDataTools.dtaDataAdapter.SelectCommand = clsDataTools.cmdComand;
    clsDataTools.dtaDataAdapter.Fill(dataGridDataSet);
    clsDataTools.con.Close();
    dataGridDataSet.Tables[0].TableName = "Orders";

    dgvCusOrders.DataSource = dataGridDataSet;
    dgvCusOrders.DataMember = dataGridDataSet.Tables["Orders"].ToString();
  }

我真的不明白为什么SelctedIndexChanged当我单击搜索按钮时会触发事件，是否有我遗漏的东西？

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1 回答 1

3

由于您设置了lstResults它将调用的数据源，因此SelectedIndexChanged您可以执行以下操作

private void btnSearch_Click(object sender, EventArgs e)
{
    //Remove the handler 
    this.lstResults.SelectedIndexChanged -= lstResults_SelectedIndexChanged;
    // 
    // Your code
    //
    this.lstResults.SelectedIndexChanged += lstResults_SelectedIndexChanged; // Add the handler 
}
于 2013-07-11T11:35:47.753 回答