如何在上下文菜单的动态循环中将变量或ID传递给特定的单击事件..我的目标是在上下文菜单中动态加载技术人员的姓名,每个单击事件必须传递其ID,然后调用我的名为assign_tech()的方法
到目前为止我的代码和我尝试过的都在这里
void loadContext()
{
query = "SELECT * FROM `tbl_technician`";
using (MySqlConnection conn = constrings.GetDBConnection())
{
try
{
conn.Open();
using (MySqlCommand cmd = new MySqlCommand(query, conn))
{
using (MySqlDataReader reader = cmd.ExecuteReader())
{
while (reader.Read())
{
ToolStripMenuItem cm = startToolStripMenuItem as ToolStripMenuItem;
cm.DropDownItems.Add(reader["technician"].ToString()).Click += MyMethod;
//cm.DropDownItems.Add(reader["technician"].ToString()).Click += (sender, e) => { MyMethod(sender, e); };
//cm.DropDownItems.Add(reader["technician"].ToString()).Click += (_sender, _e) =>
//{
// tech_id = Convert.ToInt32(reader[0]);
// //MessageBox.Show(tech_id.ToString());
//};
}
}
}
}
catch (Exception ex)
{
CMessageBox m = new CMessageBox("error\n" + ex);
m.ShowDialog();
}
finally
{
conn.Close();
}
}
}
我的点击事件代码
void MyMethod(object sender, EventArgs e)
{
// MessageBox.Show("test");
DialogResult dr = new DialogResult();
DialogueBox db = new DialogueBox("Are you sure you want to assign this Record!");
dr = db.ShowDialog();
if (dr == DialogResult.Yes)
{
assign_tech();
loadData();
loadTechnicianData();
}
}
我分配技术的代码
void assign_tech()
{
if (tech_id>0)
{
using (MySqlConnection conn = constrings.GetDBConnection())
{
try
{
conn.Open();
query = "UPDATE `tbl_job_order` SET `t_id` = @tech_id, status= 'Servicing' WHERE `tbl_job_order`.`j_id` = @id;";
using (MySqlCommand cmd = new MySqlCommand(query, conn))
{
cmd.Parameters.AddWithValue("@tech_id", tech_id);
cmd.Parameters.AddWithValue("@id", selected_id);
cmd.ExecuteNonQuery();
}
}
catch (Exception ex)
{
CMessageBox m = new CMessageBox("error \n" + ex);
m.ShowDialog();
}
finally
{
conn.Close();
}
}
}
}
答案 0 :(得分:1)
ToolStripDropDownItem
专门从Tag
继承ToolStripItem
属性。 Tag
是object
的属性,因此您可以为其分配任何所需的内容。在API文档(here)中,他们使用它来保存字符串,但是您可以在其中放置任何喜欢的东西。
在内部循环的loadContext
方法中,将新创建的Tag
的{{1}}属性设置为ToolStripDropDownItem
记录的ID:
tbl_technician
现在,您可以在处理程序中提取ID值并将其传递给while (reader.Read())
{
ToolStripMenuItem cm = startToolStripMenuItem as ToolStripMenuItem;
var item = cm.DropDownItems.Add(reader["technician"].ToString());
item.Click += MyMethod;
item.Tag = Convert.ToInt32(reader[0]);
}
方法:
assign_tech
如果您想更深入一点,可以将记录加载到适当的类实例中,然后将该实例存储在void MyMethod(object sender, EventArgs e)
{
// get tech id from sender's Tag
if (!(sender is TooStripDropDownItem item) || !(item.Tag is int tech_id))
return;
// MessageBox.Show("test");
DialogResult dr = new DialogResult();
DialogueBox db = new DialogueBox("Are you sure you want to assign this Record!");
dr = db.ShowDialog();
if (dr == DialogResult.Yes)
{
assign_tech(tech_id);
loadData();
loadTechnicianData();
}
}
属性中,以便可以使用更多信息。