本菜初學C#了,有個小程序:MessageBox點是就顯示窗體,否則結束
編譯環境VS2012 .net 4.5
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace P7_1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
this.Load += Form1_Load;
}
void Form1_Load(object sender, EventArgs e)
{
DialogResult result = MessageBox.Show("kkk", "adf", MessageBoxButtons.OKCancel, MessageBoxIcon.Question);
if (result == DialogResult.Cancel)
{
this.Close();
}
else if (result == DialogResult.OK)
{
this.FormClosing += Form1_FormClosing;
}
}
void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
if (MessageBox.Show("sadf", "adf", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button2) == DialogResult.No)
{
e.Cancel = true;
}
}
}
}
咦?爲啥彈窗兩次呢?
後來找大牛問了下,問題出在
this.Load += Form1_Load;
實際上,現在不填充Load成員也會跑一遍Form1_Load了,所以這行代碼會導致MessageBox彈出兩次