[英]UI unresponsive + progress bar not working while using backgroundworker c#
我正在Visual Studio中使用WPF應用程序,我需要下載一個大文件並將其解壓縮到我的代碼中。 有人建議我使用后台工作者,但是現在當我嘗試增加進度條上的值時,它不起作用...有人可以幫忙嗎?
public void InstallVersion(string version)
{
string location = File.ReadAllText(@"C:\Users\" + Environment.UserName + @"\AppData\Roaming\MidnightFallsLauncher\data\locator.txt");
location = location + @"\Versions\" + version;
if (File.Exists(location + ".zip"))
File.Delete(location + ".zip");
if (Directory.Exists(location))
{
DirectoryInfo di = new DirectoryInfo(location);
foreach (FileInfo file in di.GetFiles())
{
file.Delete();
}
foreach (DirectoryInfo dir in di.GetDirectories())
{
dir.Delete(true);
}
}
if (!myWorker.IsBusy)
{
myWorker.RunWorkerAsync();
}
}
這是我的工作人員代碼
public MainWindow()
{
InitializeComponent();
myWorker.DoWork += new DoWorkEventHandler(myWorker_DoWork);
myWorker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(myWorker_RunWorkerCompleted);
myWorker.ProgressChanged += new ProgressChangedEventHandler(myWorker_ProgressChanged);
myWorker.WorkerReportsProgress = true;
myWorker.WorkerSupportsCancellation = true;
}
protected void myWorker_DoWork(object sender, DoWorkEventArgs e)
{
string location = File.ReadAllText(@"C:\Users\" + Environment.UserName + @"\AppData\Roaming\MidnightFallsLauncher\data\locator.txt");
location = location + @"\Versions\" + Version;
WebClient Client = new WebClient();
string url = "";
string content = "";
string downloadlink = "";
List<string> availibleVersions = new List<string>();
List<string> versionDownload = new List<string>();
url = "https://midnightfalls.glitch.me/versions.html";
content = Client.DownloadString(url);
foreach (string line in content.Split(new string[] { "<br>", "<br />" }, StringSplitOptions.None))
{
if (line.Contains("0"))
{
availibleVersions.Add(line);
}
}
url = "https://midnightfalls.glitch.me/versionslink.html";
content = Client.DownloadString(url);
foreach (string line in content.Split(new string[] { "<br>", "<br />" }, StringSplitOptions.None))
{
if (line.Contains("https"))
{
versionDownload.Add(line);
}
}
for (var i = 0; i < availibleVersions.Count; i++)
{
if (availibleVersions[i] == Version)
{
downloadlink = versionDownload[i];
}
}
Client.DownloadFile(downloadlink, location + ".zip");
ZipFile.ExtractToDirectory(location + ".zip", location);
File.Delete(location + ".zip");
RunGame(Version);
}
protected void myWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
}
protected void myWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
this.Dispatcher.Invoke(() =>
{
progress.Value += 10;
});
}
另外,當我的工作人員正在運行時,UI會凍結……我敢肯定這不會發生。
編輯: UI現在正在更新,但是進度欄仍然無法正常工作...
我敢肯定,您是在這里封鎖:
while (this.myWorker.IsBusy)
{
this.Dispatcher.Invoke(() =>
{
progress.Value += 10;
});
}
您應該在myWorker_DoWork
方法中的BackgroundWorker
實例上調用ReportProgress
。
另外,如果您使用的是.NET 4.5或更高版本,則可以完全轉儲BackgroundWorker
並使用async
/ await
模式重寫此代碼。
看起來問題在於后台線程執行工作時主線程一直在工作:
while (this.myWorker.IsBusy)
{
this.Dispatcher.Invoke(() =>
{
progress.Value += 10;
});
}
意味着您的主線程在后台作業正在工作時一直在做事,這就是UI不更新的原因。
您需要將進度更新移至后台工作程序(您還可以在其中設置一個實際上有意義的值,例如,指示已下載了多少個“ availableVersion”)。
希望有道理。
編輯:
假設我們將所有代碼直接放在視圖中,因此假設我們有一個名為“ progressBar”的進度條和一個名為“ btnStart”的按鈕(由背景工作人員踢出)。
下面是代碼:
private BackgroundWorker worker;
public MainWindow()
{
InitializeComponent();
this.worker = new BackgroundWorker();
this.worker.DoWork += new DoWorkEventHandler(myWorker_DoWork);
this.worker.RunWorkerCompleted += new
RunWorkerCompletedEventHandler(myWorker_RunWorkerCompleted);
this.worker.ProgressChanged += new
ProgressChangedEventHandler(myWorker_ProgressChanged);
this.worker.WorkerReportsProgress = true;
this.worker.WorkerSupportsCancellation = true;
}
private void myWorker_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
this.progressBar.Value = e.ProgressPercentage;
}
private void myWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
// Whatever you need to do when finished here (alert, update a label, etc.)
}
private void myWorker_DoWork(object sender, DoWorkEventArgs e)
{
// Just loop and report new progress. Sleep a little in between each
// progress update so that it isn't over before we have a chance to see it.
for(int i=0;i<100;i++)
{
Thread.Sleep(200);
this.worker.ReportProgress(i);
}
}
private void btnStart_Click(object sender, RoutedEventArgs e)
{
this.worker.RunWorkerAsync();
}
發生的情況是后台工作人員觸發了一個事件,通知進度已更改。 主線程具有該事件的句柄,並更新進度條。 由於它是后台工作人員,因此您無需使用Dispatcher.Invoke-已經解決了。
希望該示例為您澄清一些事情。
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