How to insert an image into an Access OLE field via .NET

问题

I have an Access .mdb database and I want to insert an image from an application developed in visual C# 2010. Pictures are stored in the database in the field of OLE-object.

After adding images directly in Access they are stored in the format of an Bitmap Image. These pictures can be opened in Access with a double-click.

I have the following code:

OdbcConnection Connection = new OdbcConnection();
...
sql = "INSERT INTO film (poster) VALUES (" ' " + Image.FromFile(textBox8.Text) + " ' ");";
//texbox are stored the picture name
OdbcCommand Command = new OdbcCommand(sql, Connection);
Command.ExecuteNonQuery();

The code works well, but Access stores the picture as binary data and it cannot be opened again in Access. Please tell me how to insert the image as a Bitmap Image. Thanks.

回答1:

This is a somewhat unusual request. Most people asking about OLE imbedded images in Access are asking about how to convert them from OLE objects into raw binary data, not the other way around. Current versions of Access have features like the Image control that can display bitmap images without having to deal with the complications of OLE "wrappers" being added to the object data.

Still, here is one way to do what you requested. It uses an Access.Application object, so Access must be installed on the machine for this to work. It also requires a Form inside the Access database where

the form itself is bound to the table containing the OLE image field you want to insert,
the only control on the form is a Bound Object Frame, bound to the OLE field.

The sample code also assumes that the table being updated has a numeric primary key field named [ID].

private void button1_Click(object sender, EventArgs e)
{
    // test data
    int recordIdToUpdate = 15;
    string bmpPath = @"C:\Users\Gord\Pictures\bmpMe.bmp";

    var paths = new System.Collections.Specialized.StringCollection();
    paths.Add(bmpPath);
    Clipboard.SetFileDropList(paths);

    // COM Reference required:
    //     Microsoft Access 14.0 Object Library
    var accApp = new Microsoft.Office.Interop.Access.Application();
    accApp.OpenCurrentDatabase(@"C:\Users\Public\Database1.accdb");
    accApp.DoCmd.OpenForm(
            "PhotoForm",
            Microsoft.Office.Interop.Access.AcFormView.acNormal, 
            null,
            "ID=" + recordIdToUpdate);
    accApp.DoCmd.RunCommand(Microsoft.Office.Interop.Access.AcCommand.acCmdPaste);
    accApp.DoCmd.Close(
            Microsoft.Office.Interop.Access.AcObjectType.acForm, 
            "PhotoForm", 
            Microsoft.Office.Interop.Access.AcCloseSave.acSaveNo);
    accApp.CloseCurrentDatabase();
    accApp.Quit();
    this.Close();
}

回答2:

    private string ImageToBase64String(Image image)
    {
        using (MemoryStream stream = new MemoryStream())
        {
            image.Save(stream, image.RawFormat);
            return Convert.ToBase64String(stream.ToArray());
        }
    }

    private void SaveButton()
    {

        string Pic = ImageToBase64String(PicBox.Image);

        OleDbCommand PicSave = new OleDbCommand("INSERT INTO Picture(ID,PICTURE)VALUES(" + PicId.Text + ",'" + Pic + "')", con);
        con.Open();
        var SaveValue = PicSave.ExecuteNonQuery();
        if (SaveValue > 0)
        {
            MessageBox.Show("Record Saved", "Information");
            ValueClear();
        }
        else
            MessageBox.Show("Rocord Not Saved", "Erro Msg");
        con.Close();
    }

来源：https://stackoverflow.com/questions/21497937/how-to-insert-an-image-into-an-access-ole-field-via-net

标签

database

image

ms-access

ole