CodeGo.net>在对象中使用BackgroundWorker并更新UI
作者：互联网
编辑：希望到某个地方
这是我所拥有的,但是我不确定如何将bcLoad.ReportProgress(i)委派给创建的对象(即如何进行委派以便可以传递).我已经创建了可以工作的对象事件(可以调用我的对象方法,并且可以看到在线阅读时触发的更改).我知道objectChanged何时工作(写入控制台).但是,bcLoad_RunWorkerCompleted似乎不起作用,if语句中的代码从未执行过,所以我在某个地方出错了.该文件虽然加载.
有人可以阐明如何创建委托,然后在哪部分使用传递委托(我在对象中假设),以及为什么bcLoad_RunWorkerComplete为null.
这确实是我第一次在C#中使用事件,委托和背景工作人员
/*
The object which does file operations
*/
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Collections;
using System.Windows.Forms;
using System.ComponentModel;
using System.Data;
namespace aodProductionViewer
{
public class fileOperationsSpecial
{
public event EventHandler Changed;
protected virtual void OnChanged(EventArgs e)
{
if (Changed != null)
{
Changed(this, e);
}
}
public fileOperationsSpecial()
{ }
/// <summary>
/// Count the number of lines in the file specified.
/// </summary>
/// <param name="f">The filename to count lines in.</param>
/// <returns>The number of lines in the file.</returns>
static long CountLinesInFile(string f)
{
long count = 0;
try
{
using (StreamReader r = new StreamReader(f))
{
string line;
while ((line = r.ReadLine()) != null)
{
count++;
}
}
}
catch (Exception err)
{
string strTemp = "Error get number of lines for save game file. \n" +
err.ToString();
errorDialog errDiag = new errorDialog("save game line count",
strTemp, true);
}
return count;
}
/// <summary>
/// Use this to readin in a file
/// </summary>
/// <param name="strPath">Path of file to read in</param>
/// <returns>a string array of the file</returns>
public string[] readFile(string strPath)
{
long lng_LineCount = CountLinesInFile(strPath);
string[] strReadIn = new string[lng_LineCount];
try
{
long lngCount = 0;
using (StreamReader reader = new StreamReader(strPath))
{
String line;
while ((line = reader.ReadLine()) != null)
{
strReadIn[lngCount] = line;
lngCount++;
OnChanged(EventArgs.Empty);
}
}
}
catch (Exception err)
{ //
}
return strReadIn;
}
}
}
/*
Event Listner
*/
using System;
using System.Collections.Generic;
using System.Text;
namespace aodProductionViewer
{
class EventListener
{
private fileOperationsSpecial FPS;
public EventListener(fileOperationsSpecial _fps)
{
FPS = _fps;
FPS.Changed += new EventHandler(objectChanged);
}
private void objectChanged(object sender, EventArgs e)
{ //changed has occured
}
public void Detach()
{
FPS.Changed -= new EventHandler(objectChanged);
FPS = null;
}
}
}
/*
The backgroundWorker code (Part of)
*/
BackgroundWorker bcLoad = new BackgroundWorker();
private void btt_load_save_game_Click(object sender, EventArgs e)
{
//Do some file dialog stuff
string strPath = null;
bcLoad.RunWorkerAsync(strPath);
}
void bcLoad_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
tb_ProgressBar.Value = e.ProgressPercentage;
}
void bcLoad_DoWork(object sender, DoWorkEventArgs e)
{
string strPath = e.Argument as string;
fileOperationsSpecial FPS = new fileOperationsSpecial();
EventListener listener = new EventListener(FPS);
string strArray = FPS.readFile(strPath);
listener.Detach();
}
void bcLoad_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
if (e.Result != null)
{
//Everything done
tb_ProgressBar.Visible = false;
}
}
我的主旨是使用BackgroundWorker进行一些工作并更新UI以进行进度和完成,此刻我已经有了一些简单的方法,如您所见,我传递了一个字符串(这是一条路径),然后读取文件并更新进度,目前,我只是在休眠线程并为演示目的设置进度.我也打算返回一个对象(字符串数组),但是我还没有解决这个问题.
现在我的问题是,如何在我的表单创建的对象中执行所有这些操作并仍然更新UI？我有一个当前对文件进行操作的对象(即读取文件,写入,获取信息).
目前,按照我的理解,下面的演示正在进行
表格>后台工作人员>更新表单以获取进度.
我想去
表格>创建对象>后台工作人员>更新进度表>返回字符串数组
我已经看过了,并且没有在任何示例中做任何事情,所以我想问问那些会知道的人.这有可能吗？我试图针对的是从表单中删除所有文件处理,以便于管理和维护.
有关如何执行此操作的完整代码示例将非常棒！
这是到目前为止我所了解的(请记住,仅出于示例目的,它将无法编译)
BackgroundWorker bcLoad = new BackgroundWorker();
public frm_ProductionViewer()
{
InitializeComponent();
load_settings();
bcLoad.DoWork += new DoWorkEventHandler(bcLoad_DoWork);
bcLoad.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bcLoad_RunWorkerCompleted);
bcLoad.WorkerReportsProgress = true;
bcLoad.ProgressChanged += new ProgressChangedEventHandler(bcLoad_ProgressChanged);
bcLoad.WorkerSupportsCancellation = true;
}
private void btt_load_save_game_Click(object sender, EventArgs e)
{
ts_label_GameLoaded.Text = "Loading";
bcLoad.RunWorkerAsync(strPath);
}
void bcLoad_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
tb_ProgressBar.Value = e.ProgressPercentage;
}
void bcLoad_DoWork(object sender, DoWorkEventArgs e)
{
string strPath = e.Argument as string;
//load file
//Update progress
bcLoad.ReportProgress(80);
Thread.Sleep(300 * 5);
bcLoad.ReportProgress(100);
}
void bcLoad_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
if (e.Result != null)
{
textBox1.Text = "done";
}
tb_ProgressBar.Visible = false; ;
ts_label_GameLoaded.Text = "Loaded";
}
解决方法:
您的对象(可处理文件)最好不依赖于GUI或Bgw.
因此,保持您的Bgw与(在表单上)并调用对象表单DoWork.
要报告反馈,您的Object需要一个事件(或使用委托参数的主要方法).
在该事件的处理程序中(在工作线程上调用),调用bcLoad.ReportProgress(percent).
对编辑的反应：
>您需要一个带有百分比空间的EventArgs类型,例如EventHandler< ProgressEventArgs> ,您可能必须编写ProgressEventArgs.
>我认为您不需要单独的EventListener类.这是表格工作.那会让你：
class Form ...
{
private void objectChanged(object sender, ProgressEventArgs e)
{ //changed has occured
// trigger the Bgw event
// or use Form.Invoke here to set the progress directly
bcLoad.ReportProgress(e.Percentage);
}
}
因此,“更改”现在通过2个事件处理程序进行过滤. 1打破FPS的依赖性,1同步到Form.
标签：multithreading,backgroundworker,c,user-interface,winforms 来源： https://codeday.me/bug/20191209/2097513.html