Question

从二进制数据中检索图像时遇到问题。

我将图片保存为数据库varbinary(max)并且工作正常，但是当我想在我的应用中显示我的图片时，MemoryStream会在函数byteArrayToImage中抛出错误< / p>

无效参数

这些是我将Image转换为二进制和二进制转换为图像的函数：

public byte[] imageToByteArray(System.Drawing.Image imageIn)
{
        MemoryStream ms = new MemoryStream();
        imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
        return ms.ToArray();
}

public Image byteArrayToImage(byte[] byteArrayIn)
{
        MemoryStream ms = new MemoryStream(byteArrayIn);
        System.Drawing.Image returnImage = Image.FromStream(ms);
        return returnImage;
}

这是添加代码：

private void button2_Click(object sender, EventArgs e)
{
        openFileDialog1.Filter = "All Images|*.jpg; *.bmp; *.png";
        byte[] img = imageToByteArray(pictureBox1.Image);

        string CorrectFileName = System.IO.Path.GetFileName(openFileDialog1.FileName);

        String HotelName = comboBox1.Text;
        String RoomName = comboBox2.Text;

        Dictionary<string, object> parametri = new Dictionary<string, object>(){
            { "Name", CorrectFileName },
            { "RoomName1", RoomName },
            { "HotelName1", HotelName },
            { "PictureDate", img }
        };

        AppHotels.DbHelper.IzvrsiProceduru("AddPicture", parametri);       
        MessageBox.Show("Image added");
    }

这是显示图片的代码：

（我设置了一个断点来查看字节数组，看起来很好！ByteArr返回byte [26]）

private void button3_Click(object sender, EventArgs e)
{
        flowLayoutPanel1.Controls.Clear();
        String HotelName = comboBox3.Text;

        Dictionary<string, object> parametri = new Dictionary<string, object>(){
          { "HotelName", HotelName }  
        };

        DataTable d = new DataTable();
        d = AppHotels.DbHelper.IzvrsiProceduru("ShowPictures", parametri);

        byte[] byteArr = GetBytes((String)d.Rows[0]["PictureDate"]);

        Button b = new Button();
        b.BackgroundImageLayout = ImageLayout.Stretch;
        b.BackgroundImage = byteArrayToImage(byteArr);
        b.Height = 250;
        b.Width = 200;
        flowLayoutPanel1.Controls.Add(b);
   }

我很抱歉这篇长篇文章。谢谢大家的阅读。

Answer 1

我通过使用此代码从数据库获取字节数组来解决问题：

private void button1_Click_2(object sender, EventArgs e)  
{
    byte[] imgData;

    using (SqlConnection conn = new SqlConnection(AppHotels.DbHelper.getConn()))
    {
            conn.Open();
            string cmdText = "SELECT PictureDate from dbo.Pictures ";
            SqlCommand cmd = new SqlCommand(cmdText, conn);

            using (SqlDataReader reader = cmd.ExecuteReader())
            {
                while (reader.Read())
                {

                    long bufLength = reader.GetBytes(0, 0, null, 0, 0);
                    imgData = new byte[bufLength];
                    reader.GetBytes(0, 0, imgData, 0, (int)bufLength);


                    MemoryStream ms = new MemoryStream(imgData);
                    ms.Position = 0;

                    Button b = new Button();
                    b.BackgroundImageLayout = ImageLayout.Stretch;
                    b.BackgroundImage = Image.FromStream(ms);
                    b.Height = 250;
                    b.Width = 200;
                    flowLayoutPanel1.Controls.Add(b);
                }
            }
        }
    }

（错误：参数无效）如何从数据库二进制文件中检索图像 - ＆gt;图像（SQL Server +存储过程）桌面应用程序

1 个答案: