c#如何从数据库中检索图像 [英] How to retrieve image from database in c#

问题描述

一个错误显示我有此代码的无效参数...谁能告诉我怎么了?我应该得到分配给 clientID 的图像.

an error shows saying that I have invalid parameters for this code... can anyone tell me whats wrong? Im supposed to get the image assigned to the clientID.

private void button1_Click(object sender, EventArgs e)
{
        MySqlConnection conn = new MySqlConnection(mycon);
        MySqlCommand cmd = new MySqlCommand("SELECT clientImage FROM client WHERE clientID='" + label2.Text + "'", conn);

        conn.Open();
        MySqlDataReader myReader = null;
        myReader = cmd.ExecuteReader();

        while (myReader.Read())
        {
            byte[] imgg = (byte[])(myReader["clientImage"]);
            if (imgg == null)
            {
                pictureBox1.Image = null;
            }
            else
            {
                MemoryStream mstream = new MemoryStream(imgg);
                pictureBox1.Image = System.Drawing.Image.FromStream(mstream);
            }
        }
        conn.Close();
}

推荐答案

此代码有效.MySql Wamp.

this code works. MySql Wamp.

using System.IO;

string appPath = Path.GetDirectoryName(Application.Executable) + @"/student Images/";
string imagename;

//put this code below to load form.
getimage();
if(File.Exist(appPath + imagename)
{
PictureBox1.Image = Image.FromFile(appPath + imagename);
}
else
{
PictureBox1.Image = Properties.Resources.Image_notfound;
}

private void getimage()
{
MySqlConnection connect = new MySqlConnection(con);
MySqlCommand cmd = new MySqlCommand("SELECT PictureName as 'pic' FROM userprofile where ID='" + datagrid.CurrentRow.Cells["ID"].ToString() + "'");
cmd.CommandType = CommandType.Text;
cmd.Connection = connect;
connect.Open();
Try
{
MySqlDataReader dr = cmd.ExecuteReader();
while(dr.Read())
{
imagename = dr.GetString("pic");
}
dr.Close();
}
catch(Exception ee)
{
Console.WriteLine(ee.ToString());
}
finally
{
connect.Close();
}

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