I'm trying to make a "simple" program, all it does is to list all opened programs and, once you choose one, it opens it inside your window (like a thumbnail you may say, but you can also interact).
One thing, it has to be one way only (I can't alter the embbeded program and add a "socket" or "plug" for instance). I want to be able to embbed any program (e.g. Opera, evince, JDownloader etc).
Does anyone have any idea of how can I do it?
If it can't be done using GTK, can it be done using X or any similar? How?
It appears that you're looking for something like XEmbed. A good tutorial in python and gtk is at http://www.moeraki.com/pygtktutorial/pygtk2tutorial/sec-PlugsAndSockets.html
You can use GtkPlug and GtkSocket for that.
using System;using Gtk;using System.Runtime.InteropServices; public partial class MainWindow : Gtk.Window{
public MainWindow () : base(Gtk.WindowType.Toplevel)
{
Gtk.Socket socket;
int xid;
Fixed fixed2=new Fixed();
this.socket = new Socket();
this.socket.WidthRequest = 500;
this.socket.HeightRequest = 500;
this.socket.Visible = true;
this.socket.Realized += new EventHandler(OnVideoWidgetRealized);
fixed2.Put(socket, 0, 0);
fixed2.SetSizeRequest(500,500);
this.Add(fixed2);
this.ShowAll();
OnButton17Clicked();
}
protected virtual void OnVideoWidgetRealized (object sender, EventArgs
args)
{
this.xid = (int)socket.Id;
Console.WriteLine("this.xid:"+this.xid);
}
protected void OnDeleteEvent (object sender, DeleteEventArgs a)
{
Application.Quit ();
a.RetVal = true;
this.socket = new Socket();
}
protected void OnButton17Clicked ()
{
var paramString = string.Format("-wid {0} 1.avi", xid);
System.Diagnostics.Process proc = new System.Diagnostics.Process();
proc.StartInfo.FileName = "mplayer.exe";
proc.StartInfo.Arguments = paramString;
proc.Start();
proc.WaitForExit();
}
public static void Main()
{
Application.Init();
new MainWindow();
Application.Run();
}}
Related
I am trying to learn programming for fun (apologies in advance if I get the terminology wrong) and have found an issue that I am struggling to solve. I have been trying to get a program to interact with key a key being pressed (e.g: you press "space" and the console will print "hello world") and am unable to get the event and method to interact.
What am I doing wrong; is it a simple step I've missed or have I got the structure completely wrong?
Thank you!
Code
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace Key_Input_2
{
class MainProgram
{
static void Main(string[] args)
{
KeyInput_2 k = new KeyInput_2();
bool keyType = k.dKey_KeyDown();
if (keyType == true)
{
Console.WriteLine("Hello World");
}
}
}
class KeyInput_2
{
bool dKey = false;
public bool dKey_KeyDown(object sender, KeyEventArgs e)
{
while (dKey == false)
{
if (e.KeyCode == Keys.D)
{
return true;
}
else
{
return false;
}
}
}
}
}
Start with this:
public bool dKey_KeyDown()
{
var key = Console.ReadKey();
if (key == ConsoleKey.D)
{
return true;
}
else
{
return false;
}
}
The code you have posted won't work at all.
First, you are calling dKey_KeyDown without any arguments, but the declaration of this method requires two arguments, object sender, and KeyEventArgs e...so the code won't even compile, let alone run.
Second, it looks like you might have copied and pasted this from some example code from Windows Forms coding; in this case sender and e are supplied by the Forms code as part of its event handling mechanism. I won't go into the details here, but it won't work in a Console application..you can read more about it here
In the interest of helping out, here is a simple program that will do what you want, it uses Console.ReadKey
using System;
namespace SimpleKey
{
class Program
{
static void Main(string[] args)
{
//make a variable to store the input from the user's keypress
ConsoleKeyInfo input = new ConsoleKeyInfo();
//keep executing the code inside the block ({..}) until the user presses the Spacebar
while (input.Key != ConsoleKey.Spacebar)
{
Console.WriteLine("Press SpaceBar...");
input = Console.ReadKey();
}
//now they have pressed spacebar, so display the message
Console.WriteLine("Hello World");
}
}
}
Finally - congratulations on deciding to take up programming! Stick with it, you'll be glad you did :)
I was making a program and I stumbled across this two-in-one problem, where the first problem leads to the other. I have not yet found a question where someone had both problems leading into eachother. I'm still learing, and have learned a lot from other problems I had, but I can't find a solution to this problem.
It has to do with threading. I want to make a thread, that can place something in a rich textbox every second or so, while I can still press buttons to start and stop it. But to make a function that a thread can run, I need to make the function static. Otherwise I'll get the error "A field initializer cannot reference the non-static field, method, or property". But when a function is static, it cannot acces any of the created items, like richTextBox1. Because if I try to change it's text, I get the error "Error 1 An object reference is required for the non-static field, method, or property". And if I fix this by removing static, the thread will not work.
I made a demo program that is smaller than the full one, but has the same problem. Button1 is the button to start the thread, Button2 is the one to stop it.
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;
using System.Threading;
namespace threading_non_static_problem_demo
{
public partial class Form1 : Form
{
static Thread thr = new Thread(new ThreadStart(demofunc));
int checkthr = 0; //int to check if the thread has been running before (I like to do things like this)
int ifthrrun = 0; //int to check if the thread is running
public Form1()
{
InitializeComponent();
button2.Enabled = false; // so you can't click the "stop" button if nothing is running
}
private void richTextBox1_TextChanged(object sender, EventArgs e)
{
}
static void demofunc()
{
while (true)
{
Thread.Sleep(1000);
richTextBox1.Text = richTextBox1.Text + "text added"; // <-- here's the problem
MessageBox.Show("tried to add text"); // you can use this messagebox to check if the thread is working correctly
}
}
private void button1_Click(object sender, EventArgs e)
{
if (checkthr == 0) // check if the thread has run before, 0 is no, 1 is yes, and then start or resume it
{
thr.Start();
ifthrrun = 1;
button2.Enabled = true;
button1.Enabled = false;
}
else if (checkthr == 1)
{
thr.Resume();
ifthrrun = 1;
button2.Enabled = true;
button1.Enabled = false;
}
}
private void button2_Click(object sender, EventArgs e)
{
thr.Suspend();
checkthr = 1;
ifthrrun = 0;
button2.Enabled = false;
button1.Enabled = true;
}
protected override void OnFormClosing(FormClosingEventArgs e) // if the program is closing, check the thread's state and act accordingly
{
if (ifthrrun == 0)
{
if (checkthr == 1)
{
thr.Resume();
thr.Abort();
}
else if (checkthr == 0)
{
}
}
else if (ifthrrun == 1)
{
thr.Abort();
}
}
}
}
To use this code just creat a forms application, add two buttons, and a rich text box, it should work.
Thank you in advance for you answers.
But to make a function that a thread can run, I need to make the
function static.
Get rid of the static declarations and move initialization of your "thr" variable to the constructor like this:
Thread thr;
public Form1()
{
InitializeComponent();
button2.Enabled = false; // so you can't click the "stop" button if nothing is running
thr = new Thread(new ThreadStart(demofunc));
Control.CheckForIllegalCrossThreadCalls = false;
}
private void demofunc()
{
while (true)
{
Thread.Sleep(1000);
richTextBox1.Text = richTextBox1.Text + "text added"; // <-- problem "solved" by disabling Control.CheckForIllegalCrossThreadCalls
}
}
But ignore the above "fix" because using Suspend()/Resume() is not recommended.
See Pausing and Resuming Threads:
Important
Starting with the .NET Framework version 2.0, the Thread.Suspend and
Thread.Resume methods are marked obsolete and will be removed in a
future release.
The Thread.Suspend and Thread.Resume methods are not
generally useful for applications and should not be confused with
synchronization mechanisms. Because Thread.Suspend and Thread.Resume
do not rely on the cooperation of the thread being controlled, they
are highly intrusive and can result in serious application problems
like deadlocks (for example, if you suspend a thread that holds a
resource that another thread will need).
One way to be able to pause/resume your loop would be to use a ManualResetEvent like this:
Thread thr;
ManualResetEvent mre = new ManualResetEvent(false);
public Form1()
{
InitializeComponent();
button2.Enabled = false; // so you can't click the "stop" button if nothing is running
thr = new Thread(new ThreadStart(demofunc));
}
private void demofunc()
{
while (!this.IsDisposed && !this.Disposing)
{
Thread.Sleep(1000);
if (!this.IsDisposed && !this.Disposing)
{
this.Invoke((MethodInvoker)delegate {
richTextBox1.AppendText("text added");
});
}
mre.WaitOne();
}
}
private void button1_Click(object sender, EventArgs e)
{
button1.Enabled = false;
mre.Set();
if (!thr.IsAlive)
{
thr.Start();
}
button2.Enabled = true;
}
private void button2_Click(object sender, EventArgs e)
{
button2.Enabled = false;
mre.Reset();
button1.Enabled = true;
}
protected override void OnFormClosing(FormClosingEventArgs e) // if the program is closing, check the thread's state and act accordingly
{
mre.Set(); // make sure the loop continues so it can drop out
}
}
I'm currently trying to use multi-threaded Gtk# under Windows.
Everything works fine except for this little bug that makes the application unusable : you can't move or resize the app, because it freezes.
It looks like a potential bug in Gtk#.
Here's a sample that reproduces the issue : a simple window, a label and a button. The label and button are not necessary, but provide the proof that otherwise Gtk is performing normally. Whenever I move the windows, maximize it, it stalls.
using System;
using Gtk;
namespace FreezingWindow
{
class MainClass
{
public static void Main (string[] args)
{
if (GLib.Thread.Supported) {
GLib.Thread.Init ();
}
Gdk.Threads.Init ();
Gdk.Threads.Enter ();
Application.Init ();
Window win = new Window ("test");
var box = new VBox ();
var label = new Label ("Test");
box.PackStart (label);
var btn = new Button ("Test");
btn.Clicked += delegate(object sender, EventArgs e) {
label.Text = DateTime.Now.ToString();
};
box.PackStart (btn);
win.Add (box);
win.ShowAll ();
Application.Run ();
Gdk.Threads.Leave ();
}
}
}
Here's how I work with multi-threading + GUI changes. I completely avoid the threading methods you've utilized and stictly use the System.Threading namespace. It creates true multi-threaded applications with responsive GUI. (Also, I typically create a separate class that is strictly for the form and all of its methods.)
// Create the thread and tell it to execute the DoThreadStuff method.
Thread thread = new Thread(new ThreadStart(DoThreadStuff));
thread.Start();
Update the GUI by utilizing Application.Invoke.
private void DoThreadStuff()
{
// Stuff that is processing on the separate thread.
// Need to use Application.Invoke if updating the GUI from the thread.
Application.Invoke(delegate {
label.Text = string.Format("Did stuff at {0}", DateTime.Now);
});
}
Another method I like to use is to create a generic method that accepts a method name that we need to execute under Application.Invoke.
private void InvokeMethod(System.Action methodName)
{
Application.Invoke(delegate {
methodName();
});
}
my web application offers a download. Javascript creats at the click the url (it depends on the user input) and the browser should open it, so that the page isn't reloaded.
For that, I think I have to alternatives:
// Alt1:
window.open(pathToFile);
// Alt2:
var downloadFrame = document.getElementById('downloads');
if (downloadFrame === null) {
downloadFrame = document.createElement('iframe');
downloadFrame.id = 'downloads';
downloadFrame.style.display = 'none';
document.body.appendChild(downloadFrame);
}
downloadFrame.src = pathToFile;
Both works under Firefox. Problem with open new window method: If the creation of the file at the server needs more time, the new empty tab will be closed late.
Problem with iframe: If there is an error at the server, no feedback is given.
I think at firefox the iframe is the better solution. But the web application must run with an JavaFX WebView, too. JavaFX haven't a download feature, I have to write it. One possible way is to listen on the location property:
final WebView webView = new WebView();
webView.getEngine().locationProperty().addListener(new ChangeListener<String>() {
#Override public void changed(ObservableValue<? extends String> observableValue, String oldLoc, String newLoc) {
if (newLoc.cotains("/download")) {
FileChooser chooser = new FileChooser();
chooser.setTitle("Save " + newLoc);
File saveFile = chooser.showSaveDialog(webView.getEngine().getScene().getWindow());
if (saveFile != null) {
BufferedInputStream is = null;
BufferedOutputStream os = null;
try {
is = new BufferedInputStream(new URL(newLoc).openStream());
os = new BufferedOutputStream(new FileOutputStream(saveFile));
while ((readBytes = is.read()) != -1) {
os.write(b);
}
} finally {
try { if (is != null) is.close(); } catch (IOException e) {}
try { if (os != null) os.close(); } catch (IOException e) {}
}
}
}
}
}
There are some problems:
The download start depends on a part of the url, because JafaFX supports no access to the http headers (that is bearable)
If the user starts the download with the same url two times, only the first download works (the change event only fires, if the url is new). I can crate unique urls (with #1, #2 and so on at the end). But this is ugly.
Only the "window.open(pathToFile);" method works. Loading an iframe don't fire the change location event of the website. That is expectable but I haven't found the right Listener.
Can someone help me to solve 2. or 3.?
Thank you!
PS: Sorry for my bad english.
edit:
For 2. I found a way. I don't know if it is a good one, if it is performant, if the new webview is deleted or is in the cache after download, ....
And the user don't get an feedback, when some a problem is raised:
webView.getEngine().setCreatePopupHandler(new Callback<PopupFeatures, WebEngine>() {
#Override public WebEngine call(PopupFeatures config) {
final WebView downloader = new WebView();
downloader.getEngine().locationProperty().addListener(/* The Listener from above */);
return downloader.getEngine();
}
}
I think you may just need to use copyURLtoFile to get the file...call that when the location changes or just call that using a registered java class. Something like this:
org.apache.commons.io.FileUtils.copyURLToFile(new URL(newLoc), new File(System.getProperty("user.home")+filename));
Using copyURLToFile the current page doesn't have to serve the file. I think registering the class is probably the easiest way to go... something like this:
PHP Code:
Download $filename
Java (in-line class in your javafx class/window... in this case my javafx window is inside of a jframe):
public class JavaApp {
JFrame cloudFrameREF;
JavaApp(JFrame cloudFrameREF)
{
this.cloudFrameREF = cloudFrameREF;
}
public void getfile(String filename) {
String newLoc = "http://your_web_site.com/send_file.php?filename=" + filename;
org.apache.commons.io.FileUtils.copyURLToFile(new URL(newLoc), new File(System.getProperty("user.home")+filename));
}
}
This part would go in the main javafx class:
Platform.runLater(new Runnable() {
#Override
public void run() {
browser2 = new WebView();
webEngine = browser2.getEngine();
appREF = new JavaApp(cloudFrame);
webEngine.getLoadWorker().stateProperty().addListener(
new ChangeListener<State>() {
#Override public void changed(ObservableValue ov, State oldState, State newState) {
if (newState == Worker.State.SUCCEEDED) {
JSObject win
= (JSObject) webEngine.executeScript("window");
// this next line registers the JavaApp class with the page... you can then call it from javascript using "app.method_name".
win.setMember("app", appREF);
}
}
});
You may not need the frame reference... I was hacking some of my own code to test this out and the ref was useful for other things...
I wanted to debug the Seed() method in my Entity Framework database configuration class when I run Update-Database from the Package Manager Console but didn't know how to do it. I wanted to share the solution with others in case they have the same issue.
Here is similar question with a solution that works really well.
It does NOT require Thread.Sleep.
Just Launches the debugger using this code.
Clipped from the answer
if (!System.Diagnostics.Debugger.IsAttached)
System.Diagnostics.Debugger.Launch();
The way I solved this was to open a new instance of Visual Studio and then open the same solution in this new instance of Visual Studio. I then attached the debugger in this new instance to the old instance (devenv.exe) while running the update-database command. This allowed me to debug the Seed method.
Just to make sure I didn't miss the breakpoint by not attaching in time I added a Thread.Sleep before the breakpoint.
I hope this helps someone.
If you need to get a specific variable's value, a quick hack is to throw an exception:
throw new Exception(variable);
A cleaner solution (I guess this requires EF 6) would IMHO be to call update-database from code:
var configuration = new DbMigrationsConfiguration<TContext>();
var databaseMigrator = new DbMigrator(configuration);
databaseMigrator.Update();
This allows you to debug the Seed method.
You may take this one step further and construct a unit test (or, more precisely, an integration test) that creates an empty test database, applies all EF migrations, runs the Seed method, and drops the test database again:
var configuration = new DbMigrationsConfiguration<TContext>();
Database.Delete("TestDatabaseNameOrConnectionString");
var databaseMigrator = new DbMigrator(configuration);
databaseMigrator.Update();
Database.Delete("TestDatabaseNameOrConnectionString");
But be careful not to run this against your development database!
I know this is an old question, but if all you want is messages, and you don't care to include references to WinForms in your project, I made some simple debug window where I can send Trace events.
For more serious and step-by-step debugging, I'll open another Visual Studio instance, but it's not necessary for simple stuff.
This is the whole code:
SeedApplicationContext.cs
using System;
using System.Data.Entity;
using System.Diagnostics;
using System.Drawing;
using System.Windows.Forms;
namespace Data.Persistence.Migrations.SeedDebug
{
public class SeedApplicationContext<T> : ApplicationContext
where T : DbContext
{
private class SeedTraceListener : TraceListener
{
private readonly SeedApplicationContext<T> _appContext;
public SeedTraceListener(SeedApplicationContext<T> appContext)
{
_appContext = appContext;
}
public override void Write(string message)
{
_appContext.WriteDebugText(message);
}
public override void WriteLine(string message)
{
_appContext.WriteDebugLine(message);
}
}
private Form _debugForm;
private TextBox _debugTextBox;
private TraceListener _traceListener;
private readonly Action<T> _seedAction;
private readonly T _dbcontext;
public Exception Exception { get; private set; }
public bool WaitBeforeExit { get; private set; }
public SeedApplicationContext(Action<T> seedAction, T dbcontext, bool waitBeforeExit = false)
{
_dbcontext = dbcontext;
_seedAction = seedAction;
WaitBeforeExit = waitBeforeExit;
_traceListener = new SeedTraceListener(this);
CreateDebugForm();
MainForm = _debugForm;
Trace.Listeners.Add(_traceListener);
}
private void CreateDebugForm()
{
var textbox = new TextBox {Multiline = true, Dock = DockStyle.Fill, ScrollBars = ScrollBars.Both, WordWrap = false};
var form = new Form {Font = new Font(#"Lucida Console", 8), Text = "Seed Trace"};
form.Controls.Add(tb);
form.Shown += OnFormShown;
_debugForm = form;
_debugTextBox = textbox;
}
private void OnFormShown(object sender, EventArgs eventArgs)
{
WriteDebugLine("Initializing seed...");
try
{
_seedAction(_dbcontext);
if(!WaitBeforeExit)
_debugForm.Close();
else
WriteDebugLine("Finished seed. Close this window to continue");
}
catch (Exception e)
{
Exception = e;
var einner = e;
while (einner != null)
{
WriteDebugLine(string.Format("[Exception {0}] {1}", einner.GetType(), einner.Message));
WriteDebugLine(einner.StackTrace);
einner = einner.InnerException;
if (einner != null)
WriteDebugLine("------- Inner Exception -------");
}
}
}
protected override void Dispose(bool disposing)
{
if (disposing && _traceListener != null)
{
Trace.Listeners.Remove(_traceListener);
_traceListener.Dispose();
_traceListener = null;
}
base.Dispose(disposing);
}
private void WriteDebugText(string message)
{
_debugTextBox.Text += message;
Application.DoEvents();
}
private void WriteDebugLine(string message)
{
WriteDebugText(message + Environment.NewLine);
}
}
}
And on your standard Configuration.cs
// ...
using System.Windows.Forms;
using Data.Persistence.Migrations.SeedDebug;
// ...
namespace Data.Persistence.Migrations
{
internal sealed class Configuration : DbMigrationsConfiguration<MyContext>
{
public Configuration()
{
// Migrations configuration here
}
protected override void Seed(MyContext context)
{
// Create our application context which will host our debug window and message loop
var appContext = new SeedApplicationContext<MyContext>(SeedInternal, context, false);
Application.Run(appContext);
var e = appContext.Exception;
Application.Exit();
// Rethrow the exception to the package manager console
if (e != null)
throw e;
}
// Our original Seed method, now with Trace support!
private void SeedInternal(MyContext context)
{
// ...
Trace.WriteLine("I'm seeding!")
// ...
}
}
}
Uh Debugging is one thing but don't forget to call:
context.Update()
Also don't wrap in try catch without a good inner exceptions spill to the console.
https://coderwall.com/p/fbcyaw/debug-into-entity-framework-code-first
with catch (DbEntityValidationException ex)
I have 2 workarounds (without Debugger.Launch() since it doesn't work for me):
To print message in Package Manager Console use exception:
throw new Exception("Your message");
Another way is to print message in file by creating a cmd process:
// Logs to file {solution folder}\seed.log data from Seed method (for DEBUG only)
private void Log(string msg)
{
string echoCmd = $"/C echo {DateTime.Now} - {msg} >> seed.log";
System.Diagnostics.Process.Start("cmd.exe", echoCmd);
}