C# winform中自定义用户控件 然后在页面中调用用户控件的事件

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace winform_test.UserControls
{
public partial class conYMPC : UserControl
{
private string sb_ym;

public string Sb_ym
{
get { return sb_ym; }
}
private string sb_pc;

public string Sb_pc
{
get { return sb_pc; }
}

//委托
public delegate void MyChangeEventHandler();
//事件
public event MyChangeEventHandler MyChange;
//方法
public void OnMyChange()
{
if (MyChange != null)
MyChange();
}

public conYMPC()
{
InitializeComponent();
}
/// <summary>
///窗体初始化
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void conYM_Load(object sender, EventArgs e)
{
BindYear();
}

/// <summary>
/// 得到年份
/// </summary>
private void BindYear()
{
string sql = "select distinct left(sb_ym,4)+'年' as sb_year from sb_ympc order by sb_year desc";
DataSet ds = SqlHelp.GetDataSet(sql);

foreach (DataRow dr in ds.Tables[0].Rows)
{
cboY.Properties.Items.Add(dr["sb_year"].ToString());
}
cboY.SelectedIndex = 0;
}
/// <summary>
/// 得到月份
/// </summary>
private void BindMonth()
{
cboM.Properties.Items.Clear();
string sql = "select distinct right(sb_ym,2)+'月' as sb_month from sb_ympc where sb_ym like '" + cboY.Text.Substring(0, 4) + "%' order by sb_month desc";
DataSet ds = SqlHelp.GetDataSet(sql);
foreach (DataRow dr in ds.Tables[0].Rows)
{
cboM.Properties.Items.Add(dr["sb_month"].ToString());
}
cboM.SelectedIndex = 0;
}
/// <summary>
/// 得到批次
/// </summary>
private void BindPC()
{
cboPC.Properties.Items.Clear();
string sql = "select sb_pc from sb_ympc where sb_ym='" + cboY.Text.Substring(0, 4) + cboM.Text.Substring(0, 2) + "' order by sb_pc";
DataSet ds = SqlHelp.GetDataSet(sql);
foreach (DataRow dr in ds.Tables[0].Rows)
{
cboPC.Properties.Items.Add(dr["sb_pc"].ToString());
}
cboPC.SelectedIndex = 0;
}
/// <summary>
/// 年份下拉列表框改变事件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void cboY_SelectedIndexChanged(object sender, EventArgs e)
{
BindMonth();
CheckChange();
}
/// <summary>
/// 月份下拉列表框改变事件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void cboM_SelectedIndexChanged(object sender, EventArgs e)
{
BindPC();
CheckChange();
}
/// <summary>
/// 批次下拉列表框改变事件
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void cboPC_SelectedIndexChanged(object sender, EventArgs e)
{
CheckChange();
}

/// <summary>
/// 检查下拉列表框的值是否改变，改变的话更新
/// </summary>
private void CheckChange()
{
string _sb_ym = cboY.Text.Substring(0, 4) + cboM.Text.Substring(0, 2);
string _sb_pc = cboPC.Text;
if (_sb_ym != sb_ym || _sb_pc != sb_pc)
{
sb_ym = _sb_ym;
sb_pc = _sb_pc;
OnMyChange();//触发这个方法
}
}
}
}

private void frmStart_Load(object sender, EventArgs e)
{
//给控件绑定事件
conYMPC1.MyChange += new UserControls.conYMPC.MyChangeEventHandler(aa);
}

void aa()
{
MessageBox.Show("申报年月：" + conYMPC1.Sb_ym + "  申报批次：" + conYMPC1.Sb_pc);
}