如何通过 BackGroundWorker(或是自己写多线程代码)实现在备份数据库时在进度条里显示备份进度(如果代码写起来麻烦指点一下方法就行了)谢
如何通过 BackGroundWorker(或是自己写多线程代码)实现在备份数据库时在进度条里显示备份进度(如果代码写起来麻烦指点一下方法就行了)谢谢! --------------------编程问答-------------------- 自己顶一下
--------------------编程问答-------------------- 再顶一下
--------------------编程问答-------------------- 应该不行吧 --------------------编程问答-------------------- 等待高人出现
应该可以 --------------------编程问答-------------------- 没用过那个，不过我都是用Invoke来实现的。 --------------------编程问答-------------------- 也就是异步调用，显示进度调。 --------------------编程问答-------------------- using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Threading;
using System.Windows.Forms;
namespace BackgroundWorkerExample
{
public class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
// Do not access the form's BackgroundWorker reference directly.
// Instead, use the reference provided by the sender parameter.
BackgroundWorker bw = sender as BackgroundWorker;
// Extract the argument.
int arg = (int)e.Argument;
// Start the time-consuming operation.
e.Result = TimeConsumingOperation(bw, arg);
// If the operation was canceled by the user,
// set the DoWorkEventArgs.Cancel property to true.
if (bw.CancellationPending)
{
e.Cancel = true;
}
}
// This event handler demonstrates how to interpret
// the outcome of the asynchronous operation implemented
// in the DoWork event handler.
private void backgroundWorker1_RunWorkerCompleted(
object sender,
RunWorkerCompletedEventArgs e)
{
if (e.Cancelled)
{
// The user canceled the operation.
MessageBox.Show("Operation was canceled");
}
else if (e.Error != null)
{
// There was an error during the operation.
string msg = String.Format("An error occurred: {0}", e.Error.Message);
MessageBox.Show(msg);
}
else
{
// The operation completed normally.
string msg = String.Format("Result = {0}", e.Result);
MessageBox.Show(msg);
}
}
// This method models an operation that may take a long time
// to run. It can be cancelled, it can raise an exception,
// or it can exit normally and return a result. These outcomes
// are chosen randomly.
private int TimeConsumingOperation(
BackgroundWorker bw,
int sleepPeriod )
{
int result = 0;
Random rand = new Random();
while (!this.backgroundWorker1.CancellationPending)
{
bool exit = false;
switch (rand.Next(3))
{
// Raise an exception.
case 0:
{
throw new Exception("An error condition occurred.");
break;
}
// Sleep for the number of milliseconds
// specified by the sleepPeriod parameter.
case 1:
{
Thread.Sleep(sleepPeriod);
break;
}
// Exit and return normally.
case 2:
{
result = 23;
exit = true;
break;
}
default:
{
break;
}
}
if( exit )
{
break;
}
}
return result;
}
private void startBtn_Click(object sender, EventArgs e)
{
this.backgroundWorker1.RunWorkerAsync(2000);
}
private void cancelBtn_Click(object sender, EventArgs e)
{
this.backgroundWorker1.CancelAsync();
}
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;
/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.backgroundWorker1 = new System.ComponentModel.BackgroundWorker();
this.startBtn = new System.Windows.Forms.Button();
this.cancelBtn = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// backgroundWorker1
//
this.backgroundWorker1.WorkerSupportsCancellation = true;
this.backgroundWorker1.DoWork += new System.ComponentModel.DoWorkEventHandler(this.backgroundWorker1_DoWork);
this.backgroundWorker1.RunWorkerCompleted += new System.ComponentModel.RunWorkerCompletedEventHandler(this.backgroundWorker1_RunWorkerCompleted);
//
// startBtn
//
this.startBtn.Location = new System.Drawing.Point(12, 12);
this.startBtn.Name = "startBtn";
this.startBtn.Size = new System.Drawing.Size(75, 23);
this.startBtn.TabIndex = 0;
this.startBtn.Text = "Start";
this.startBtn.Click += new System.EventHandler(this.startBtn_Click);
//
// cancelBtn
//
this.cancelBtn.Location = new System.Drawing.Point(94, 11);
this.cancelBtn.Name = "cancelBtn";
this.cancelBtn.Size = new System.Drawing.Size(75, 23);
this.cancelBtn.TabIndex = 1;
this.cancelBtn.Text = "Cancel";
this.cancelBtn.Click += new System.EventHandler(this.cancelBtn_Click);
//
// Form1
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(183, 49);
this.Controls.Add(this.cancelBtn);
this.Controls.Add(this.startBtn);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);
}
#endregion
private System.ComponentModel.BackgroundWorker backgroundWorker1;
private System.Windows.Forms.Button startBtn;
private System.Windows.Forms.Button cancelBtn;
}
public class Program
{
private Program()
{
}
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.Run(new Form1());
}
}
} --------------------编程问答-------------------- 用在备份数据库 好像不行
无法得到备份多少的值
--------------------编程问答-------------------- 好象进度没有办法知道。 --------------------编程问答-------------------- 学习ing....... --------------------编程问答-------------------- ding yi xia --------------------编程问答-------------------- 可以再 加100分
希望指点 --------------------编程问答-------------------- I am studing.... --------------------编程问答-------------------- 学习 --------------------编程问答-------------------- 学习
补充：.NET技术 , C#
