Question

最初我将从指定文件夹中加载图像（比如说20张图片），通过从组合框下拉菜单中选择，它们会正常加载到图片框中。

我面临的问题是，当我选择下一个文件夹来获取要处理的图像时，先前选择的文件夹图像也会在计数后显示在图片框中，只显示下一个文件夹图像，我无法清除以前加载的图像。

具体来说，当我从下拉列表中点击文件夹时，我想要图片框中的特定文件夹图像，我不想要先前加载的图像。我正在使用c＃在VS2013中工作。

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        ArrayList alist = new ArrayList();
        int i = 0;
        int filelength = 0;
        public Form1()
        {
            InitializeComponent();
        }



        private void Form1_Load(object sender, EventArgs e)
        {
            DirectoryInfo di = new      DirectoryInfo(@"C:\Users\Arun\Desktop\scanned");
            DirectoryInfo[] folders = di.GetDirectories();
            comboBox1.DataSource = folders;
        }

        private void button7_Click(object sender, EventArgs e)
        {
            if (i + 1 < filelength)
            {
                pictureBox1.Image = Image.FromFile(alist[i + 1].ToString());
                i = i + 1;
                pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
            }
        }

        private void button8_Click(object sender, EventArgs e)
        {

            if (i - 1 >= 0)
            {

                pictureBox1.Image = Image.FromFile(alist[i - 1].ToString());
                pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
                i = i - 1;
            }
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            string selected = comboBox1.SelectedItem.ToString();
            String fullpath = Path.Combine(@"C:\Users\Arun\Desktop\scanned", selected);
            DirectoryInfo di1 = new DirectoryInfo(fullpath);
            DirectoryInfo[] folders1 = di1.GetDirectories();
            comboBox2.DataSource = folders1;

        }

        private void button9_Click(object sender, EventArgs e)
        {

            string selected1 = comboBox1.SelectedItem.ToString();
            string selected2 = comboBox2.SelectedItem.ToString();

                        //Initially load all your image files into the array list when form load first time
            System.IO.DirectoryInfo inputDir = new System.IO.DirectoryInfo(Path.Combine(@"C:\Users\Arun\Desktop\scanned", selected1, selected2)); //Source image folder path


            try
            {


                if ((inputDir.Exists))
                {

                    //Get Each files 
                    System.IO.FileInfo file = null;
                    foreach (System.IO.FileInfo eachfile in inputDir.GetFiles())
                    {
                        file = eachfile;
                        if (file.Extension == ".tif")
                        {
                            alist.Add(file.FullName); //Add it in array list
                            filelength = filelength + 1;
                        }
                        else if(file.Extension == ".jpg")
                        {

                            alist.Add(file.FullName); //Add it in array list
                            filelength = filelength + 1;
                        }
                    }

                    pictureBox1.Image = Image.FromFile(alist[0].ToString());  //Display intially first image in picture box as sero index file path
                    pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
                    i = 0;

                }
            }
            catch (Exception ex)
            {

            }

        }

        private void Form1_KeyDown(object sender, KeyEventArgs e)
        {
            if(e.KeyCode == Keys.D)
            {
                if (i + 1 < filelength)
                {
                    pictureBox1.Image = Image.FromFile(alist[i + 1].ToString());
                    i = i + 1;
                    pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
                }
            }
            else if(e.KeyCode == Keys.A)
            {
                if (i - 1 >= 0)
                {

                    pictureBox1.Image = Image.FromFile(alist[i - 1].ToString());
                    pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
                    i = i - 1;
                }
            }
        }


        private void comboBox2_SelectedIndexChanged(object sender, EventArgs e)
        {

        }

  }
}

Answer 1

您的代码有许多问题。

您要查找的是在加载新文件名之前未清除alist。

所以插入：

    alist.Clear();

之前

    //Get Each files

还

   filelength = alist.Count;

循环后

。添加时无需计算！

另请注意，ArrayList几乎已被删除，您应该使用类型安全且功能强大的List<T>代替：

List<string> alist = new List<string>();

当然，名为i的类变量很愚蠢，您也依赖于在comboBox2中始终拥有SelectedItem。

由于您没有正确处理图像，因此您正在泄漏GDI资源。

您可以使用此功能正确加载图像：

void loadImage(PictureBox pbox, string file)
{
    if (pbox.Image != null)
    {
        var dummy = pbox.Image;
        pbox.Image = null;
        dummy.Dispose();
    }
    if (File.Exists(file)) pbox.Image = Image.FromFile(file);
}

首先创建对Image的引用，然后清除PictureBox的引用，然后使用对Dispose的{{1}}的引用，最后尝试加载新的。

清除图片框中的加载图像-c＃

1 个答案: