Question

我遇到以下代码的问题，用于将二进制源转换为位图图像以插入到我的图像列表中。我收到“参数无效”。

// Retrieving data from Database
private void Form1_Load(object sender, EventArgs e)
    {
        vcon.Open();
        string get = "Select Path, Images FROM IMGSTR";
        OleDbCommand cmdget = new OleDbCommand(get, vcon);
        OleDbDataReader reader;
        reader = cmdget.ExecuteReader();

        while (reader.Read())
        {
            string path = reader["Path"].ToString();

            //here is where I am receiving an error
            this.imageList1.Images.Add(Image.FromStream(new MemoryStream((byte[]) reader["Images"])));


             //creates rows in my listview to display images
            Graphics theGraphics = Graphics.FromHwnd(this.Handle);
            int count = this.listView1.Items.Count;
            for (; count < this.imageList1.Images.Count; count++)
            {
                listView1.Items.Add("", count);
            }


        }



     //Add Photos and Path to Database
    private void importImagesToolStripMenuItem_Click(object sender, EventArgs e)
    {
        FolderBrowserDialog dig = new FolderBrowserDialog();

        if (dig.ShowDialog() == DialogResult.OK)
        {
            MessageBox.Show("This May take a while. Depending on the size and amount of your photos. Click Ok to continue", "! ! !");
            foreach (String files in Directory.GetFiles(dig.SelectedPath))
            {
                if (files.EndsWith(".JPG"))
                {
                    //convert .jpg to thumbnail
                    Image image = new Bitmap(files);
                    Image pThumbnail = image.GetThumbnailImage(100, 100, null, new IntPtr());

                    //Insert Path and Image into database
                    string cmdstr = "INSERT into IMGSTR(Path, Images) values(path, image)";
                    OleDbCommand com = new OleDbCommand(cmdstr, vcon);
                    com.Parameters.AddWithValue("path", files);

                    //Storing Image into MS database as Ole Object
                    com.Parameters.AddWithValue("image", pThumbnail);

                    com.ExecuteNonQuery();

                    image.Dispose();
                }
            }
        }

任何人都可以帮助我理解为什么我收到此错误。我是计算机编程的新手，不明白为什么我自己。

Answer 1

//you are casting the blob from pulled from the db to a byte array
while(reader.Read())
{
    this.imageList1.Images.Add(Image.FromStream(
        new MemoryStream((byte[] reader["Images"])
}

但根据我的经验，图像往往存储在服务器上，并且您向数据库中的文件添加路径（链接），因为添加blob并将其读回是数据库的非常繁重的操作。

将二进制转换为图像列表的位图图像。代码错误

1 个答案: