在Gtk#窗口中刷新图像,在一定时间后图像消失

时间:2016-07-21 21:31:06

标签: c# .net gtk#

我正在使用C#,。Net 4.5和Gtk#编写一个简单的应用程序,它捕获屏幕的一部分并将其加载到窗口中的图像上。几秒钟后,图像消失,我收到以下错误:

Glib-CRITICAL **:尝试删除时未找到源ID xxxx。

相关代码:

的Program.cs:

using System.Windows.Forms;

namespace Dota2Trainer
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            Gtk.Application.Init();
            MiniMapOverlay myWin = new MiniMapOverlay();
            myWin.KeepAbove = true;
            //myWin.Decorated = false;
            myWin.Resize(200, 200);
            myWin.ShowAll();
            ScreenCapturer screenCap = new ScreenCapturer(30, Screen.PrimaryScreen.Bounds.Width, Screen.PrimaryScreen.Bounds.Height, myWin);
            screenCap.Start();
            Gtk.Application.Run();
        }
    }
}

MiniMapOverlay.cs:

using System;
using System.Drawing;
using System.IO;
using System.Timers;
using Gtk;

namespace Dota2Trainer
{
    public partial class MiniMapOverlay : Gtk.Window
    {
        Gtk.Image image = null;
        public MiniMapOverlay() : base(Gtk.WindowType.Toplevel)
        {
            image = new Gtk.Image();
            var buffer = System.IO.File.ReadAllBytes(".\\image0.jpeg");
            var pixbuf = new Gdk.Pixbuf(buffer);
            image.Pixbuf = pixbuf;
            this.Add(image);
            this.Build();
        }

        public void RefreshImage(byte[] buffer)
        {
            try
            {
                var pixbuf = new Gdk.Pixbuf(buffer);
                image.Pixbuf = pixbuf;
            }
            catch (Exception exception)
            {
                Console.WriteLine(exception.Message);
            }
        }
    }
}

ScreenCapturer.cs:

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Timers;

namespace Dota2Trainer
{
    public delegate void OnSavedImage(byte[] screenCap);
    public class ScreenCapturer
    {
        public System.Timers.Timer aTimer;
        int interval= 30000;
        readonly int screenWidth;
        readonly int screenHeight;
        Rectangle bounds;
        const double miniMapWidthPercentage = 0.15;
        const double miniMapHeightPercentage = 0.25;
        Bitmap bitmap;
        bool Busy = false;
        ImageConverter converter = new ImageConverter();
        public OnSavedImage onSaveImage;

        public ScreenCapturer(int interval, int screenWidth, int screenHeight, MiniMapOverlay imageHolder)
        {
            this.screenHeight = screenHeight;
            this.screenWidth = screenWidth;
            this.interval = interval;
            aTimer = new System.Timers.Timer();
            aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
            aTimer.Interval = this.interval;
            int miniMapWidth = (int)(screenWidth * miniMapWidthPercentage);
            int miniMapHeight = (int)(screenHeight * miniMapHeightPercentage);
            int miniMapStartWidth = (screenWidth - miniMapWidth);
            int miniMapStartHeight = (screenHeight - miniMapHeight);

            bounds = new Rectangle(miniMapStartWidth, miniMapStartHeight, miniMapWidth, miniMapHeight);
            bitmap = new Bitmap(bounds.Width, bounds.Height);
            onSaveImage += imageHolder.RefreshImage;
        }

        public void Start()
        {
            aTimer.Enabled = true;
        }

        public void OnTimedEvent(object sender, ElapsedEventArgs e)
        {
            try
            {
                if (Busy)
                    return;
                Busy = true;
                using (Graphics g = Graphics.FromImage(bitmap))
                {
                    g.CopyFromScreen(new Point(bounds.Left, bounds.Top), Point.Empty, bounds.Size);
                    onSaveImage((byte[])converter.ConvertTo(bitmap, typeof(byte[])));
                }
                Busy = false;
            }
            catch (Exception exception)
            {
                Console.WriteLine(exception.Message);
            }
        }
    }
}

完整的源代码可以在这里找到:

https://github.com/oldtimerza/Dota2Trainer

它是如何工作的只是创建一个计时器,在一定时间后运行Screencapturer类的OnTimedEvent()方法,该方法具有一个将运行MiniMapOverlay RefreshImage()方法的委托。这段代码令人震惊,但我只想在重构之前准备好一个粗略的准备版本。

我一直在寻找年龄,为什么会发生这种情况,有什么建议吗?

1 个答案:

答案 0 :(得分:1)

您应该使用Glib.Timeout代替System.TimersSystem.Timers可能存在线程问题,并且计时器事件发生在与GTK应用程序不同的线程上。 Glib.Timeout以一定的间隔在主GTK应用程序循环中对事件进行排队,并在同一个线程中运行。但是,它不适用于时间敏感函数,因为应用程序循环正在处理其他事件,例如鼠标点击。我已经看到了大约半秒到一秒的延迟,但这是在调试时的旧计算机上。这似乎不是您的应用程序的问题;仅供将来参考。此外,Glib.Timeout将继续调用更新事件,直到您返回false。

uint timerId;

public void Start(uint interval)
{
    timerId = GLib.Timeout.Add (interval, OnUpdateTimer);
}

protected bool OnUpdateTimer ()
{
    try
    {
        if (Busy)
            return;
        Busy = true;
        using (Graphics g = Graphics.FromImage(bitmap))
        {
            g.CopyFromScreen(new Point(bounds.Left, bounds.Top), Point.Empty, bounds.Size);
            onSaveImage((byte[])converter.ConvertTo(bitmap, typeof(byte[])));
        }
        Busy = false;
    }
    catch (Exception exception)
    {
        Console.WriteLine(exception.Message);
    }
    return true;
}