Question

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.IO;

namespace Player_Manager
{
    public partial class ScreenShotsPlayer : Form
    {
        FileInfo[] images;
        DirectoryInfo di1;
        int current = 0;

        public ScreenShotsPlayer()
        {
            InitializeComponent();

            di1 = new DirectoryInfo(@"e:\screenshots");
            images = di1.GetFiles("*.bmp");
        }

        private void button1_Click(object sender, EventArgs e)
        {
            timer1.Start();
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            current = (current >= images.Length - 1) ? 0 : ++current;
            pictureBox1.Image = new Bitmap(images[current].FullName);
            pictureBox1.Refresh();
        }
    }
}

硬盘上有1200张图像，定时器设置为100毫秒。在播放了大约258-270张图片后，它就会抛出内存不足的异常：

pictureBox1.Refresh();

System.OutOfMemoryException was unhandled
  HResult=-2147024882
  Message=Out of memory.
  Source=System.Drawing
  StackTrace:
       at System.Drawing.Graphics.CheckErrorStatus(Int32 status)
       at System.Drawing.Graphics.DrawImage(Image image, Int32 x, Int32 y, Int32 width, Int32 height)
       at System.Drawing.Graphics.DrawImage(Image image, Rectangle rect)
       at System.Windows.Forms.PictureBox.OnPaint(PaintEventArgs pe)
       at System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, Int16 layer)
       at System.Windows.Forms.Control.WmPaint(Message& m)
       at System.Windows.Forms.Control.WndProc(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
       at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
       at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
  InnerException:

如果我将删除行pictureBox1.Refresh（）; 然后它将抛出异常：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Player_Manager
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
}

在Application.Run行（new Form1（））;

相同的例外。

Answer 1

GDI +的问题在于它所使用的内存是无法管理的 - GC不知道你有多少浪费来触发一个集合，所以它只是在GDI +运行之前一直在堆积超出可分配的内存。

修复非常简单。您知道自己要分配的位图，只需在不再需要时将其丢弃：

    private void timer1_Tick(object sender, EventArgs e)
    {
        if(pictureBox1.Image!=null)
        {
            var img = pictureBox1.Image;  // cache it to dispose
            pictureBox1.Image = null;     // don't dispose an used object
            img.Dispose();                // and dispose of it
        }

        current = (current >= images.Length - 1) ? 0 : ++current;
        pictureBox1.Image = new Bitmap(images[current].FullName);
        pictureBox1.Refresh();
    }

为什么在尝试在pictureBox中播放图像时出现内存异常？

1 个答案: