C#读写图片文件到Access数据库中

Access数据库连接字符串 const string conStr = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\MyAccessFile\MyPicte.accdb;Persist Security Info=False"; string pic = string.Empty; //保存图片转化字符串 //选择图片并写入数据库中 private void button1_Click(object sender, EventArgs e) { //打开文件对话框选择图片文件 OpenFileDialog openfile = new OpenFileDialog(); openfile.Title = "请选择图片"; openfile.Filter="图片(*.jpg;*.bmp;*.png)|*.jpeg;*.jpg;*.bmp;*.png|AllFiles(*.*)|*.*"; if (DialogResult.OK != openfile.ShowDialog()) return; try { //显示图片到PictureBox控件中 Bitmap bmp = new Bitmap(openfile.FileName); pictureBox1.Image = bmp; pictureBox1.SizeMode = PictureBoxSizeMode.Zoom; //把图片转化成二进制，最后转成字符串 MemoryStream ms = new MemoryStream(); bmp.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg); byte[] arr = new byte[ms.Length]; ms.Position = 0; ms.Read(arr, 0, (int)ms.Length); ms.Close(); pic = Convert.ToBase64String(arr); //把Byte字节数组转成字符串 //pic = ImageToString(openfile.FileName);//自己写的图片转字符串的函数封装 //写入数据库中 OleDbConnection conn = new OleDbConnection(conStr); string sql = $"insert into mTable (pictName,pictText) values (‘{openfile.FileName}‘,‘{pic}‘)"; OleDbCommand cmd = new OleDbCommand(sql, conn); conn.Open(); int res = cmd.ExecuteNonQuery(); if (res > 0) { MessageBox.Show("图片保存成功！"); } conn.Close(); conn.Dispose(); } catch (Exception) { throw; } }

2。从数据库中读取图片文件

<span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">从数据库中读取图片，并显示在PictureBoc控件中</span>
        <span style="color: rgba(0, 0, 255, 1)">private</span> <span style="color: rgba(0, 0, 255, 1)">void</span> button2_Click(<span style="color: rgba(0, 0, 255, 1)">object</span><span style="color: rgba(0, 0, 0, 1)"> sender, EventArgs e)
        {
            </span><span style="color: rgba(0, 0, 255, 1)">int</span> id = <span style="color: rgba(128, 0, 128, 1)">6</span>;<span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">要读取的图片在数据库中的编号，因为是测试就手动修改要读取的编号</span>
            <span style="color: rgba(0, 0, 255, 1)">try</span><span style="color: rgba(0, 0, 0, 1)">
            {
                OleDbConnection conn </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> OleDbConnection(conStr);
                </span><span style="color: rgba(0, 0, 255, 1)">string</span> sql = $<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">select pictText from mTable where ID={id}</span><span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(0, 0, 0, 1)">;
                OleDbCommand cmd </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> OleDbCommand(sql, conn);
                conn.Open();
                OleDbDataAdapter oda </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> OleDbDataAdapter(cmd);
                DataTable dt </span>= <span style="color: rgba(0, 0, 255, 1)">new</span><span style="color: rgba(0, 0, 0, 1)"> DataTable();
                oda.Fill(dt);
                conn.Close();
                conn.Dispose();
                </span><span style="color: rgba(0, 0, 255, 1)">if</span>(dt.Rows.Count><span style="color: rgba(128, 0, 128, 1)">0</span><span style="color: rgba(0, 0, 0, 1)">)
                {
                    pic </span>= dt.Rows[<span style="color: rgba(128, 0, 128, 1)">0</span>][<span style="color: rgba(128, 0, 128, 1)">0</span><span style="color: rgba(0, 0, 0, 1)">].ToString();
                    </span><span style="color: rgba(0, 0, 255, 1)">if</span> (!<span style="color: rgba(0, 0, 255, 1)">string</span><span style="color: rgba(0, 0, 0, 1)">.IsNullOrEmpty(pic))
                    {
                        </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">把string转成字节数组</span>
                        <span style="color: rgba(0, 0, 255, 1)">byte</span>[] imageBytes =<span style="color: rgba(0, 0, 0, 1)"> Convert.FromBase64String(pic);
                        </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">把字节读取到内存</span>
                        MemoryStream memoryStream = <span style="color: rgba(0, 0, 255, 1)">new</span> MemoryStream(imageBytes, <span style="color: rgba(128, 0, 128, 1)">0</span><span style="color: rgba(0, 0, 0, 1)">, imageBytes.Length);
                        memoryStream.Write(imageBytes, </span><span style="color: rgba(128, 0, 128, 1)">0</span><span style="color: rgba(0, 0, 0, 1)">, imageBytes.Length);
                        </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">字节数组转成Image对象</span>
                        Image image =<span style="color: rgba(0, 0, 0, 1)"> Image.FromStream(memoryStream);
                        </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">Image image = StringToImage(pic);
                        </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">显示图片到控件中</span>
                        <span style="color: rgba(0, 0, 255, 1)">this</span>.pictureBox2.SizeMode =<span style="color: rgba(0, 0, 0, 1)"> PictureBoxSizeMode.Zoom;
                        </span><span style="color: rgba(0, 0, 255, 1)">this</span>.pictureBox2.Image =<span style="color: rgba(0, 0, 0, 1)"> image;
                    }
                }
            }
            </span><span style="color: rgba(0, 0, 255, 1)">catch</span><span style="color: rgba(0, 0, 0, 1)"> (Exception)
            {
                </span><span style="color: rgba(0, 0, 255, 1)">throw</span><span style="color: rgba(0, 0, 0, 1)">;
            }
        }</span>

学习成果展示：

 

 

好了今天就学到这了。

 

C#读写图片文件到Access数据库中

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