I'm trying to execute some Python scripts from my WPF app. The scripts are generating the log files and the code in the Tick event is reading them and displaying that as it is in a textbox.
My issue here is that, that LaunchProcess fires successfully, but the UI freezes. I have an indefinite progress bar, which too does not start animating. I'm a beginner with WPF and there is something very small I have to do to get this code working. I'm not getting any error/warnings. The scripts run fine and in the end I get to know the result too. But during the run, the UI of my app freezes.
private void LaunchProcess(string paramStr)
{
Process myProcess = new Process();
StartProgressBar();
try
{
dispatcherTimer = new DispatcherTimer();
dispatcherTimer.Tick += new EventHandler(dispatcherTimer_Tick);
dispatcherTimer.Interval = new TimeSpan(0, 0, 0);
dispatcherTimer.Start();
myProcess.StartInfo.UseShellExecute = false;
// You can start any process
myProcess.StartInfo.FileName = "C:\\Python32\\python.exe";
myProcess.StartInfo.Arguments = "\""+paramStr+"\"";
myProcess.StartInfo.CreateNoWindow = true;
myProcess.StartInfo.RedirectStandardOutput = true;
myProcess.StartInfo.RedirectStandardError = true;
myProcess.Start();
myProcess.WaitForExit();
// This code assumes the process you are starting will terminate itself.
// Given that is is started without a window so you cannot terminate it
// on the desktop, it must terminate itself or you can do it programmatically
// from this application using the Kill method.
dispatcherTimer.Stop();
}
catch
{
MessageBox.Show("Process Launch Failed!!", "Failure", MessageBoxButton.OK, MessageBoxImage.Error);
}
}
private void dispatcherTimer_Tick(object sender, EventArgs e)
{
//txtOutPut.Text = "";
txtOutPut.Text += "\n" + DateTime.Now.ToString();
if (File.Exists(scriptPath+"\\log.txt"))
{
//File.Copy("C:\\FlashAuto\\Execution_Logs\\log.txt", "C:\\FlashAuto\\Temp\\log.txt", true);
TextReader readLogs = new StreamReader(scriptPath + "\\log.txt");
string line = readLogs.ReadLine();
while (line != null)
{
txtOutPut.Text += "\n" + line;
line = readLogs.ReadLine();
txtOutPut.ScrollToEnd();
}
//CountLines = txtExecLog.LineCount - 1;
readLogs.Close();
// Forcing the CommandManager to raise the RequerySuggested event
txtOutPut.ScrollToEnd();
CommandManager.InvalidateRequerySuggested();
readLogs.Dispose();
}
else
{
txtOutPut.Text += "log file not found at: " + DateTime.Now.ToString();
}
}
In case you call LaunchProcess from the UI thread it will obviously be blocked at myProcess.WaitForExit().
You might simply remove the myProcess.WaitForExit() and dispatcherTimer.Stop() calls from the launch method and check if the process is still running in the timer Tick handler.
private void dispatcherTimer_Tick(object sender, EventArgs e)
{
if (myProcess.WaitForExit(0)) // check with timeout zero
{
dispatcherTimer.Stop();
}
... // all your code
}
Calling LaunchProcess method asynchronously would resolve your UI Freeze Issue
public void LaunchProcessAsynchrousCall(string paramStr)
{
ThreadStart displayContentHandler = delegate()
{
LaunchProcess(paramStr)
};
Thread thread = new Thread(displayContentHandler);
thread.IsBackground = true;
thread.Start();
}
Related
I'm creating a network diagnostic application and trying to add a pathping command to it where it takes an adress from a textfield as path to ping when I press a button, but the application freezes when I press the button and nothing shows in the output window.
private void btn_PingPath_Click(object sender, EventArgs e)
{
ProcessStartInfo PathPingStartInfo = new ProcessStartInfo();
PathPingStartInfo.FileName = "CMD.EXE";
PathPingStartInfo.UseShellExecute = false;
PathPingStartInfo.CreateNoWindow = true;
PathPingStartInfo.RedirectStandardOutput = true;
PathPingStartInfo.RedirectStandardInput = true;
PathPingStartInfo.RedirectStandardError = true;
PathPingStartInfo.StandardOutputEncoding = Encoding.GetEncoding(850);
Process PathPing = new Process();
PathPing.StartInfo = PathPingStartInfo;
PathPing.Start();
PathPing.StandardInput.WriteLine("PATHPING " + txt_PingPath.Text);
while (PathPing.StandardOutput.Peek() > -1)
{
txt_Output.Text = PathPing.StandardOutput.ReadLine();
}
while (PathPing.StandardError.Peek() > -1)
{
txt_Output.Text = PathPing.StandardError.ReadLine();
}
//txt_Output.Text = PathPing.StandardOutput.ReadToEnd();
PathPing.WaitForExit();
}
EDIT
I found the while loop from another question but it did not help. I still get no output in the output text window and the application still freezes.
The PATHPING command can end up running for several minutes before exiting, so your last line, PathPing.WaitForExit(); will also not return for several minutes (or until pathping exits). You can't wait like this on the UI thread, because the UI also needs to use this thread to re-draw and listen for windows messages.
You can free up the UI thread so that your application doesnt freeze by either creating a new thread, or using async/await features in .Net 4.5+, or using the event pattern. The following example uses the event pattern.
private void btn_PingPath_Click(object sender, EventArgs e)
{
ProcessStartInfo PathPingStartInfo = new ProcessStartInfo();
PathPingStartInfo.FileName = "CMD.EXE";
PathPingStartInfo.UseShellExecute = false;
PathPingStartInfo.CreateNoWindow = true;
PathPingStartInfo.RedirectStandardOutput = true;
PathPingStartInfo.RedirectStandardInput = true;
PathPingStartInfo.RedirectStandardError = true;
PathPingStartInfo.StandardOutputEncoding = Encoding.GetEncoding(850);
Process PathPing = new Process();
PathPing.StartInfo = PathPingStartInfo;
PathPing.Start();
PathPing.StandardInput.WriteLine("PATHPING " + txt_PingPath.Text);
PathPing.StandardInput.Flush();
PathPing.OutputDataReceived += (o, args) => txt_Output.Text += args.Data;
PathPing.ErrorDataReceived += (o, args) => txt_Output.Text += args.Data;
PathPing.BeginErrorReadLine();
PathPing.BeginOutputReadLine();
}
I've created a thread (or I'm trying to) which will autosave every so many minutes. Whenever I click the button to start the thread, the program doesn't autosave as instructed. So I'm reaching out for help. Here's the code:
private Thread saver;
...
saver.SetApartmentState(System.Threading.ApartmentState.STA);
saver = new Thread(new ThreadStart(SaveRegularly));
saver.Start();
Here's my SaveRegularly method:
private bool stopAndDie = false;
private void SaveRegularly()
{
//DateTime saveDueAt = DateTime.Now.AddMinutes(0.25);
//do
//{
//Thread.Sleep(1000);
//if (DateTime.Now >= saveDueAt)
//{
if (SaveDoc.FileName != "") //ADDED THIS TODAY (24/09)
{
CreateWordDocument(FilePath, SaveDoc.FileName, pathImage);
MessageBox.Show("Updated");
return;
}
else
{
if (SaveDoc.ShowDialog() == DialogResult.OK)
{
CreateWordDocument(FilePath, SaveDoc.FileName, pathImage);
MessageBox.Show("New Save");
return;
}
}
timer1.Start();
}
This is for the FormClosing Event, so the thread stops.
stopAndDie = true;
saver.Join(2000);
timer1.Stop();
When I run the program and I click the save button, I receive an error at the SaveFileDialog line (if (SaveDoc.ShowDialog() == DialogResult.OK)).Here is the error I receive.
Set the thread to STA mode.
saver.SetApartmentState(System.Threading.ApartmentState.STA);
But why aren't you using timers if you want to schedule something periodically?
Something like this:
System.Timers.Timer timer = new System.Timers.Timer(5 * 60 * 1000);
timer.Elapsed += (s, e) =>
{
//Invoke your show dialog on the UI thread here
};
timer.Start();
And when you want it to stop just call timer.Stop();
Below is my code so far, I am having an issue when I call Dispatcher.BeginInvoke, it does not process these messages at the correct time
Class Script:
public void Execute()
{
var process = new Process();
var startinfo = new ProcessStartInfo("cmd.exe", #"/C c:\test\my.bat");
startinfo.WorkingDirectory = "c:\\test";
startinfo.RedirectStandardOutput = true;
startinfo.RedirectStandardError = true;
startinfo.UseShellExecute = false;
startinfo.CreateNoWindow = true;
process.EnableRaisingEvents = true;
process.StartInfo = startinfo;
process.OutputDataReceived += (sender, args) => OutputDataReceived(args.Data);
process.ErrorDataReceived += (sender, args) => ErrorDataReceived(args.Data);
process.Exited += Exited;
process.Start();
process.BeginOutputReadLine();
process.BeginErrorReadLine();
process.WaitForExit();
int exitCode = process.ExitCode;
}
public void OutputDataReceived(string data)
{
Logging.Logger.Log("data received in script - " + data);
// throw event if we have a subscriber, else just return
if (OnScriptOutPut == null) return;
allFormattedOutPut += Environment.NewLine;
allFormattedOutPut += data;
allRawOutPut += data;
ScriptOutputEventArgs args = new ScriptOutputEventArgs(data);
OnScriptOutPut(this, args);
}
WPF Window calls the script class and subscribes to OnScriptOutPut event
The problem is below, UpdateOutPutTextBox only gets called after the script is finished, then all the updateoutputtextbox messages are processed all at once, they do not get processed when the begininvoke is called causing the screen to get updated at the end instead of when new output data is received.. Any help is appreciated!
private void btnRunScript_Click(object sender, RoutedEventArgs e)
{
Script script = new Script();
script.OnScriptOutPut += script_OnScriptOutPut;
script.Execute();
}
private void script_OnScriptOutPut(object sender, ScriptOutputEventArgs args)
{
Application.Current.Dispatcher.BeginInvoke(new Action(() => UpdateOutPutTextBox(args.Data)),System.Windows.Threading.DispatcherPriority.Send);
Logging.Logger.Log("data received in event ");
}
private void UpdateOutPutTextBox(string data)
{
Logging.Logger.Log("data received in update "+data);
tbOutput.Text += Environment.NewLine;
tbOutput.Text += data;
}
You are calling Execute on the UI thread and blocking the thread with WaitForExit. Then all of the BeginInvoke actions are getting queued up. Remove the call to WaitForExit. If you need to do something with the exit code, get the value in the Exited event handler.
I can not go through the whole code out there,
But looking into your query,
Dispatcher.BeginInvoke
BeginInvoke -> is like calling async , and async operations may take time depending on the conditions, use Invoke instead if you can, your code is alot ! reduse it if possible!
what is wrong why is that the richtextbox doesnt get the stream of Process output? theres no text display in richtextbox..
private void button1_Click(object sender, EventArgs e)
{
Process sortProcess;
sortProcess = new Process();
sortProcess.StartInfo.FileName = "sort.exe";
sortProcess.StartInfo.Arguments = this.comboBox1.SelectedItem.ToString();
// Set UseShellExecute to false for redirection.
sortProcess.StartInfo.CreateNoWindow = true;
sortProcess.StartInfo.UseShellExecute = false;
// Redirect the standard output of the sort command.
// This stream is read asynchronously using an event handler.
sortProcess.StartInfo.RedirectStandardOutput = true;
sortOutput = new StringBuilder("");
// Set our event handler to asynchronously read the sort output.
sortProcess.OutputDataReceived += new DataReceivedEventHandler(SortOutputHandler);
// Redirect standard input as well. This stream
// is used synchronously.
sortProcess.StartInfo.RedirectStandardInput = true;
// Start the process.
sortProcess.Start();
// Start the asynchronous read of the sort output stream.
sortProcess.BeginOutputReadLine();
sortProcess.WaitForExit();
richTextBox1.AppendText(sortOutput.ToString());
}
private static void SortOutputHandler(object sendingProcess,
DataReceivedEventArgs outLine)
{
sortOutput.Append(Environment.NewLine +
"[" + numOutputLines.ToString() + "] - " + outLine.Data);
}
}
so when sort.exe launches, it displays text, i want all those text be displayed also in richtextbox in RealTime (i dont want to wait for the process to exit, and then read all output)
how can i do it? any wrong part of my code? thanks
UPDATE #botz
i added this in my code
private void SortOutputHandler(object sendingProcess,
DataReceivedEventArgs outLine)
{
sortOutput.Append(Environment.NewLine +
"[" + numOutputLines.ToString() + "] - " + outLine.Data);
richTextBox1.AppendText(sortOutput.ToString());
}
but it throws this exception
Cross-thread operation not valid: Control 'richTextBox1' accessed from a thread other than the thread it was created on.
WaitForExit() blocks your UI Thread, so you don't see the new output.
Either wait for the process in a separate thread or replace WaitForExit() with something like this:
while (!sortProcess.HasExited) {
Application.DoEvents(); // This keeps your form responsive by processing events
}
In your SortOutputHandler, you can now directly append output to your textbox. But you should remember to check if you need to invoke it on the UI Thread.
You can check if it's on the UI thread this way in your handler:
if (richTextBox1.InvokeRequired) { richTextBox1.BeginInvoke(new DataReceivedEventHandler(SortOutputHandler), new[] { sendingProcess, outLine }); }
else {
sortOutput.Append(Environment.NewLine + "[" + numOutputLines.ToString() + "] - " + outLine.Data);
richTextBox1.AppendText(sortOutput.ToString());
}
This is working for me:
private void button1_Click(object sender, EventArgs e)
{
using (Process sortProcess = new Process())
{
sortProcess.StartInfo.FileName = #"F:\echo_hello.bat";
sortProcess.StartInfo.CreateNoWindow = true;
sortProcess.StartInfo.UseShellExecute = false;
sortProcess.StartInfo.RedirectStandardOutput = true;
// Set event handler
sortProcess.OutputDataReceived += new DataReceivedEventHandler(SortOutputHandler);
// Start the process.
sortProcess.Start();
// Start the asynchronous read
sortProcess.BeginOutputReadLine();
sortProcess.WaitForExit();
}
}
void SortOutputHandler(object sender, DataReceivedEventArgs e)
{
Trace.WriteLine(e.Data);
this.BeginInvoke(new MethodInvoker(() =>
{
richTextBox1.AppendText(e.Data ?? string.Empty);
}));
}
The example you started with was a console application, which doesn't care much about multithreaded access. For Windows Forms when you update a control this has to be done from the main UI thread, which is why BeginInvoke is needed. If you want to check rapidly if a handler like SortOutputHandler is working properly you can use System.Diagnostics.Trace.Write*, which doesn't need BeginInvoke.
EDIT: echo_hello.bat simply echoes the "hello" string:
#echo off
echo hello
If you are going to update the ui from another thread, you need to make sure you are on the main ui thread. In the method check for InvokeRequired. See InvokeRequired
Complete application and source code available from this external link of codeproject :
http://www.codeproject.com/Articles/335909/Embedding-a-Console-in-a-C-Application
This is tutorial of implementation of https://github.com/dwmkerr/consolecontrol.
As I said in the comment I posted to the question, by definition of what a sort does, it is impossible for there to be any output until all the input has been read. So the sort program is a bad example of getting output in realtime. So the following is for anyone in the future that wants to do something like this for console programs in general. The following uses a BackgroundWorker to get the output asynchronously and put it into a TextBox. A RichTextBox could easily be used instead.
public partial class MainWindow : Window
{
const string Path = #"C:\Windows\system32\sort.exe";
BackgroundWorker Processer = new BackgroundWorker();
public MainWindow()
{
InitializeComponent();
Processer.WorkerReportsProgress = true;
Processer.WorkerSupportsCancellation = true;
Processer.ProgressChanged += Processer_ProgressChanged;
Processer.DoWork += Processer_DoWork;
}
private void Processer_DoWork(object sender, DoWorkEventArgs e)
{
StreamReader StandardOutput = e.Argument as StreamReader;
string data = StandardOutput.ReadLine();
while (data != null)
{
Processer.ReportProgress(0, data);
data = StandardOutput.ReadLine();
}
}
private void Processer_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
string data = e.UserState as string;
if (data != null)
DataBox.Text += data + "\r\n";
}
private void Window_Loaded(object sender, RoutedEventArgs e)
{
DataBox.Text = string.Empty;
ProcessStartInfo StartInfo = new ProcessStartInfo(Path);
StartInfo.RedirectStandardOutput = true;
StartInfo.RedirectStandardInput = true;
StartInfo.UseShellExecute = false;
Process p = null;
try { p = Process.Start(StartInfo); }
catch (Exception ex)
{
MessageBox.Show($"Error starting {Path}: {ex.Message}");
return;
}
// Get the output
Processer.RunWorkerAsync(p.StandardOutput);
// Put the input
p.StandardInput.WriteLine("John");
p.StandardInput.WriteLine("Alice");
p.StandardInput.WriteLine("Zoe");
p.StandardInput.WriteLine("Bob");
p.StandardInput.WriteLine("Mary");
// Tell the program that is the last of the data
p.StandardInput.Close();
}
}
For the sort program it is not necessary to call ReportProgress until after all the data has been read but this is a more generalized sample.
For instance, a thread that is a BackgroundWorker, can be cast like:
private void worker_DoWork(object sender, DoWorkEventArgs e)
{
System.ComponentModel.BackgroundWorker senderWorker
= sender as System.ComponentModel.BackgroundWorker;
}
The code above represents what I have for my Background worker thread. I cast [sender] as a BackGround Worker - because I know thats what he is.
I can't seem to find what I should cast it to if: instead of a Background worker, what if I had used a Process class, and executed say a DOS batch file, using:
enter code here
Process proc = new Process();
proc.FileName = "some_dos_batch_file.bat";
proc.Exited = ProcessExited;
proc.Start();
Sorry about syntax, but when this process completes, its completion will be handled by 'ProcessExited' below. But What should I cast the sender arg to in THAT case - NOT a Background Worker obviously, but I'm not sure to what? I would like to use the .Results property the same as I did for the Background worker.
Thanks - sorry for the confusion.
enter code here
void ProcessExited(object sender, EventArgs e)
{
}
I hope I have understood your question, if not, please clarify. If you are talking about threading and using the System.Diagnostics.Process then you would need to use Thread events...consider this below a simple class called TestARP that shells out to the command line using a hidden window to retrieve the MAC/IP address of the active connection, with the output of the command redirected to a stream which is appended to a stringbuilder instance:
public class TestARP
{
private StringBuilder sbRedirectedOutput = new StringBuilder();
public string OutputData
{
get { return this.sbRedirectedOutput.ToString(); }
}
public void Run()
{
System.Diagnostics.ProcessStartInfo ps = new System.Diagnostics.ProcessStartInfo();
ps.FileName = "arp";
ps.ErrorDialog = false;
ps.Arguments = "-a";
ps.CreateNoWindow = true;
ps.UseShellExecute = false;
ps.RedirectStandardOutput = true;
ps.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;
using (System.Diagnostics.Process proc = new System.Diagnostics.Process())
{
proc.StartInfo = ps;
proc.Exited += new EventHandler(proc_Exited);
proc.OutputDataReceived += new System.Diagnostics.DataReceivedEventHandler(proc_OutputDataReceived);
proc.Start();
proc.WaitForExit();
proc.BeginOutputReadLine();
while (!proc.HasExited) ;
}
}
void proc_Exited(object sender, EventArgs e)
{
System.Diagnostics.Debug.WriteLine("proc_Exited: Process Ended");
}
void proc_OutputDataReceived(object sender, System.Diagnostics.DataReceivedEventArgs e)
{
if (e.Data != null) this.sbRedirectedOutput.Append(e.Data + Environment.NewLine);
//System.Diagnostics.Debug.WriteLine("proc_OutputDataReceived: Data: " + e.Data);
}
}
If you were to run this in a thread the Process's events will still get caught (only on the thread itself), but if you're talking about waiting for the thread to finish, look at this class code here called ThreadTestARP that runs the above class on a thread...
public class ThreadTestARP
{
private TestARP _testARP = new TestARP();
private ManualResetEvent _mre = new ManualResetEvent(false);
public ThreadTestARP()
{
}
public TestARP ARPTest
{
get { return this._testARP; }
}
public void Run()
{
Thread t = new Thread(new ThreadStart(RunThread));
t.Start();
this._mre.WaitOne();
// Blocks here...
t.Join();
}
private void RunThread()
{
this._testARP.Run();
this._mre.Set();
}
}
Note how the ManualResetEvent _mre is used to signal to say in the context of the thread, "right, I am done, back to the creator..."
Why can't you cast to a Process object? You can still access some members of Process objects, such as ExitCode or ExitTime, that have terminated.
http://msdn.microsoft.com/en-us/library/system.diagnostics.process.exited.aspx