把图片保存到数据库中和从数据库中读取图片-tutorial mysql-php.cn

最近做到一个小项目，其中关系到图片的一些操作。比如：将图片保存到数据库中、从数据库中读取图片、显示图片、打印图片等。此处对这些在项目中遇到的一些琐碎知识加以总结，以便日后查找。 1、将图片作为其中的一个参数保存到数据库中在项目中，一般是将图

　　最近做到一个小项目，其中关系到图片的一些操作。比如：将图片保存到数据库中、从数据库中读取图片、显示图片、打印图片等。此处对这些在项目中遇到的一些琐碎知识加以总结，以便日后查找。

　　1、将图片作为其中的一个参数保存到数据库中

　　在项目中，一般是将图片转换成二进制流格式，然后保存到数据库中。同时数据库表中存储图片的格式一般为image。此次项目，是将图片作为一个参数，和其他几个参数一起保存到数据库中，和在网上搜索到的图片保存不太一样，此处稍作修改，但都是检测过的。

　　存储步骤：

　　1、搜索到图片的路径

　　2、读取图片并将图片转换成二进制流格式

　　3、sql语句保存到数据库中。

　　贴代码：　

<span>private</span> <span>void</span> btnWrite_Click(<span>object</span><span> sender, EventArgs e)
        {
            OpenFileDialog ofd </span>= <span>new</span><span> OpenFileDialog();
            ofd.Filter </span>= <span>"</span><span>*jpg|*.JPG|*.GIF|*.GIF|*.BMP|*.BMP</span><span>"</span><span>;

            </span><span>if</span> (ofd.ShowDialog() ==<span> DialogResult.OK)
            {
                </span><span>string</span> filePath = ofd.FileName;<span>//</span><span>图片路径</span>
                FileStream fs = <span>new</span><span> FileStream(filePath, FileMode.Open);
                </span><span>byte</span>[] imageBytes = <span>new</span> <span>byte</span><span>[fs.Length];
                BinaryReader br </span>= <span>new</span><span> BinaryReader(fs);
                imageBytes </span>= br.ReadBytes(Convert.ToInt32(fs.Length));<span>//</span><span>图片转换成二进制流</span>

                <span>string</span> strSql = <span>string</span>.Format(<span>"</span><span>insert into [SBS].[dbo].[Model] ([M_QRCode],[M_Skills] ) values (@image,'2')</span><span>"</span><span>);
                </span><span>int</span> count =<span> Write(strSql,imageBytes );

                </span><span>if</span> (count > <span>0</span><span>)
                {
                    MessageBox.Show(</span><span>"</span><span>success</span><span>"</span><span>);
                }
                </span><span>else</span><span>
                {
                    MessageBox.Show(</span><span>"</span><span>failed</span><span>"</span><span>);
                }
            }
        }</span>

Salin selepas log masuk

　　数据库连接和保存图片语句：

把图片保存到数据库中和从数据库中读取图片

<span>private</span> <span>int</span> Write(<span>string</span> strSql,<span>byte</span><span>[] imageBytes)
        {
            </span><span>string</span> connStr = <span>"</span><span>Data Source=192.168.4.132;initial Catalog=SBS;User ID=sa;Password=sa;</span><span>"</span><span>;

            </span><span>using</span> (SqlConnection conn = <span>new</span><span> SqlConnection(connStr))
            {
                </span><span>using</span> (SqlCommand cmd = <span>new</span><span> SqlCommand(strSql, conn))
                {
                    </span><span>try</span><span>
                    {
                        conn.Open();
                        SqlParameter sqlParameter </span>= <span>new</span> SqlParameter(<span>"</span><span>@image</span><span>"</span><span>, SqlDbType.Image);
                        sqlParameter.Value </span>=<span> imageBytes;
                        cmd.Parameters.Add(sqlParameter);
                        </span><span>int</span> rows =<span> cmd.ExecuteNonQuery();
                        </span><span>return</span><span> rows;
                    }
                    </span><span>catch</span><span> (Exception e)
                    {
                        </span><span>throw</span><span>;
                    }
                }
            }
        }</span>

Salin selepas log masuk

View Code

　　2、从数据库总读取图片

　　从数据库中读取图片字段，并转换成内存流生成bitmap。

　　贴代码:　

<span>private</span> <span>void</span> btnRead_Click(<span>object</span><span> sender, EventArgs e)
        {
            </span><span>string</span> strSql = <span>string</span>.Format(<span>"</span><span>select M_QRCode from [SBS].[dbo].[Model] where M_id = 7</span><span>"</span>);<span>//</span><span>图片保存的字段是M_QRCode</span>
<span>            Read(strSql);
        }

        </span><span>private</span> <span>void</span> Read(<span>string</span><span> strSql)
        {
            </span><span>string</span> connStr = <span>"</span><span>Data Source=192.168.4.132;initial Catalog=SBS;User ID=sa;Password=sa;</span><span>"</span><span>;

            </span><span>using</span> (SqlConnection conn = <span>new</span><span> SqlConnection(connStr))
            {
                </span><span>using</span> (SqlCommand cmd = <span>new</span><span> SqlCommand(strSql, conn))
                {
                    conn.Open();
                    SqlDataReader sqlDr </span>=<span> cmd.ExecuteReader();
                    sqlDr.Read();
                    </span><span>byte</span>[] images = (<span>byte</span>[])sqlDr[<span>"</span><span>M_QRCode</span><span>"</span><span>];
                    MemoryStream ms </span>= <span>new</span><span> MemoryStream(images);
                    Bitmap bmp </span>= <span>new</span><span> Bitmap(ms);
                    pictureBox1.Image </span>=<span> bmp;
                }
            }
        }</span>

Salin selepas log masuk

　　3、根据图片路径显示图片

　　这个比较简单，直接贴出代码　

<span>private</span> <span>void</span> btnLoad_Click(<span>object</span><span> sender, EventArgs e)
        {
            OpenFileDialog ofd </span>= <span>new</span><span> OpenFileDialog();
            ofd.Filter </span>= <span>"</span><span>*jpg|*.JPG|*.GIF|*.GIF|*.BMP|*.BMP</span><span>"</span><span>;
            </span><span>if</span> (ofd.ShowDialog() ==<span> DialogResult.OK)
            {
                pictureBox1.Image </span>=<span> Image.FromFile(ofd.FileName);
            }
        }</span>

Salin selepas log masuk

　　4、打印图片

　　打印图片是在将图片显示在pictureBox的基础上进行的。

　　步骤：

　　1、将printDocument控件拖到界面，添加打印代码

　　2、设置PrintDocument控件的Print_PrintPage事件

<span>private</span> <span>void</span> btnPrint_Click(<span>object</span><span> sender, EventArgs e)
        {
            PrintDialog printDialog </span>= <span>new</span><span> PrintDialog();
            printDialog.Document </span>= <span>this</span><span>.printDocument1;
            </span><span>if</span> (printDialog.ShowDialog() ==<span> DialogResult.OK)
            {
                </span><span>try</span><span>
                {
                    printDocument1.Print();
                }
                </span><span>catch</span><span> (Exception ex)
                {
                   printDocument1.PrintController.OnEndPrint(printDocument1, </span><span>new</span><span> System.Drawing.Printing.PrintEventArgs());
                }
            }
        }

        </span><span>private</span> <span>void</span> printDocument1_PrintPage(<span>object</span><span> sender, System.Drawing.Printing.PrintPageEventArgs e)
        {
            e.Graphics.DrawImage(pictureBox1.Image, </span><span>30</span>, <span>30</span><span>);
        }</span>

Salin selepas log masuk

　　附带着将图片转换成二进制和将二进制转换成图片专门写出来，以便于查看。　

 <span>public</span> <span>byte</span>[] ConvertBinary(<span>string</span><span> filePath)
        {
            FileStream fs </span>= <span>new</span> FileStream(filePath, FileMode.Open, FileAccess.Read);<span>//</span><span>以文件流形式读取图片</span>
            BinaryReader br = <span>new</span> BinaryReader(fs);<span>//</span><span>转换成二进制流</span>
            <span>byte</span>[] imageBytes = br.ReadBytes((<span>int</span>)fs.Length);<span>//</span><span>保存到字节数组中</span>

            <span>return</span><span> imageBytes;
        }

        </span><span>public</span> <span>void</span> ShowImage(<span>byte</span><span>[] imageBytes)
        {
            MemoryStream ms </span>= <span>new</span><span> MemoryStream(imageBytes);
            pictureBox1.Image </span>=<span> Image.FromStream(ms);
        }</span>

Salin selepas log masuk

　　在pictureBox中显示图片的三种方式：　

<span>public</span> <span>void</span><span> Method()
        {
            MemoryStream ms;
            pictureBox1.Image </span>=<span> Image.FromStream(ms);

            Bitmap bitmap;
            pictureBox1.Image </span>=<span> bitmap;

            </span><span>string</span><span> filePath;
            pictureBox1.Image </span>=<span> Image.FromFile(filePath);
        }</span>

Salin selepas log masuk

　　winform中控件combobox控件使用：　

<span>public</span> <span>void</span><span> BindCombobox()
        {
            DataTable dt </span>= <span>new</span><span> DataTable();
            dt.Columns.Add(</span><span>new</span> DataColumn(<span>"</span><span>id</span><span>"</span>, <span>typeof</span>(<span>int</span><span>)));
            dt.Columns.Add(</span><span>new</span> DataColumn(<span>"</span><span>value</span><span>"</span>, <span>typeof</span>(<span>string</span><span>)));

            </span><span>for</span> (<span>int</span> i = <span>0</span>; i 3; i++<span>)
            {
                DataRow dr </span>=<span> dt.NewRow();
                dr[</span><span>"</span><span>id</span><span>"</span>] =<span> i;
                dr[</span><span>"</span><span>value</span><span>"</span>] = <span>10</span> +<span> i;
                dt.Rows.Add(dr);
            }

            </span><span>this</span>.comboBox1.DataSource =<span> dt;
            </span><span>this</span>.comboBox1.DisplayMember = <span>"</span><span>value</span><span>"</span><span>;
            </span><span>this</span>.comboBox1.ValueMember = <span>"</span><span>id</span><span>"</span><span>; 
        }

        </span><span>public</span> <span>void</span><span> ShowValue()
        {
            </span><span>this</span>.textBox1.Text = <span>this</span><span>.comboBox1.Text;
            </span><span>this</span>.textBox2.Text = <span>this</span><span>.comboBox1.SelectedValue.ToString();
        }</span>

Salin selepas log masuk

　　以上就是一些琐碎的总结，谨作为日后学习工作使用。