Question

我正在使用WinForms。在我的表格中我有一个图片框。该程序在“C：\ image \”目录中查找指定的图像文档，在我的例子中是一个tif文件。 “C：\ image \”目录中始终只有一张图片。

在找到文件后，程序会在图片框中显示图像文档。

当我运行时，我看到CPU使用率很高。我的目标是提高性能，或者找出是否有更好的编码方式。

我需要做什么：我必须手动进入我的C：\ image \目录并删除当前的图像文档，然后在其中放置一个新图像文档，这样我的图片框就会显示新的图像文件。

简而言之，我必须删除旧的图像文档并将其替换为新的图像文档，这样我才能在我的图片框中查看新的图像文档。

   int picWidth, picHeight;

    private void Form1_Load(object sender, EventArgs e)
    {
        timer1_Tick(sender, e);
    }

    private void File_Length()
    {
        try
        {
            string path = @"C:\image\";
            string[] filename = Directory.GetFiles(path, "*.tif"); //gets a specific image doc.

            FileInfo fi = new FileInfo(filename[0]);
            byte[] buff = new byte[fi.Length];
            using (FileStream fs = File.OpenRead(filename[0]))
            {
                fs.Read(buff, 0, (int)fi.Length);
            }
            MemoryStream ms = new MemoryStream(buff);
            Bitmap img1 = new Bitmap(ms);
            //opened = true; // the files was opened.
            pictureBox1.Image = img1;

            pictureBox1.Width = img1.Width;
            pictureBox1.Height = img1.Height;
            picWidth = pictureBox1.Width;
            picHeight = pictureBox1.Height;
        }
        catch(Exception)
        {
            //MessageBox.Show(ex.Message);
        }
    }

    public void InitTimer()
    {
        timer1 = new Timer(); 
        timer1.Tick += new EventHandler(timer1_Tick); //calls method
        timer1.Interval = 2000; // in miliseconds (1 second = 1000 millisecond)
        timer1.Start(); //starts timer
    }

    private void timer1_Tick(object sender, EventArgs e)
    {
        File_Length(); //checking the file length every 2000 miliseconds
    }

Answer 1

按文件日期检查新图像的文件夹并更改图像 - 工作示例：

    int picWidth, picHeight;
    Timer timer1;
    DateTime oldfiledate;

    public void InitTimer()
    {
        timer1 = new Timer();
        timer1.Tick += new EventHandler(timer1_Tick); //add event
        timer1.Interval = 2000; // in miliseconds (1 second = 1000 millisecond)
        timer1.Start(); //starts timer
    }

    private void timer1_Tick(object sender, EventArgs e)
    {
        ChangeImage(); //call check&change function
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        timer1_Tick(sender, e);  //raise timer event once to load image on start
        InitTimer();
    }

    private void ChangeImage()
    {
        string filename = @"c:\image\display.tif";

        DateTime filedate = File.GetLastWriteTime(filename);

        if (filedate > oldfiledate)   // change image only if the date is newer
        {
            FileInfo fi = new FileInfo(filename);
            byte[] buff = new byte[fi.Length];
            using (FileStream fs = File.OpenRead(filename))  //read-only mode
            {
                fs.Read(buff, 0, (int)fi.Length);
            }
            MemoryStream ms = new MemoryStream(buff);

            Bitmap img1 = new Bitmap(ms);
            pictureBox1.Image = img1;

            pictureBox1.Width = img1.Width;
            pictureBox1.Height = img1.Height;
            picWidth = pictureBox1.Width;
            picHeight = pictureBox1.Height;
            oldfiledate = filedate;  //remember last file date
        }
    }

在C＃2010Ex.net 4客户端配置文件上测试。

在Picturebox中显示新图像文档的更好方法

1 个答案: