C#對(duì)Oracle數(shù)據(jù)庫(kù)中圖片的處理

由于Oracle課程設(shè)計(jì)中涉及到圖片的處理，測(cè)試了好長(zhǎng)的時(shí)間和查閱了很多的資料，終于把這個(gè)問題解決了，在這和大家分享一下：

一、圖片保存到數(shù)據(jù)庫(kù)

Oracle中一般保存圖片的類型為blob，一般的步驟為：

1，首先把圖片轉(zhuǎn)化為二進(jìn)制（byte[])

　　　　FileStream fs = new FileStream(filepath, FileMode.Open, FileAccess.Read);
-
 

                byte[] buffByte = new byte[fs.Length];
                fs.Read(buffByte, 0, Convert.ToInt32(fs.Length));
                fs.Close();

2,把二進(jìn)制保存到Oracle數(shù)據(jù)庫(kù)

　　　　 string strconn = "data source = oem;user id= exam; password=exam;persist security info=false;";
                OracleConnection conn = new OracleConnection(strconn);
                conn.Open();
                OracleCommand comm = new OracleCommand("addUser", conn);//存儲(chǔ)過程adduser
                comm.CommandType = CommandType.StoredProcedure;
                comm.Parameters.Add("i_name", OracleType.VarChar, 50);
                comm.Parameters.Add("i_pic", OracleType.Blob);
                //comm.Parameters.Add("i_result", OracleType.Int32);
                comm.Parameters[0].Value = this.textBox2.Text;
                comm.Parameters[1].Value = buffByte;//這個(gè)為圖片的二進(jìn)制形式
                //comm.Parameters[2].Direction = ParameterDirection.Output;
                comm.ExecuteNonQuery();

　　　　conn.Close();

二、讀取Oracle數(shù)據(jù)庫(kù)轉(zhuǎn)化為圖片www.linuxidc.com

步驟：

1、讀出二進(jìn)制

 string strconn = "data source = oem;user id= exam; password=exam;persist security info=false;";
            OracleConnection conn = new OracleConnection(strconn);
            conn.Open();
            OracleCommand comm = new OracleCommand("selectUser", conn);
            comm.CommandType = CommandType.StoredProcedure;
            comm.Parameters.Add("flag", OracleType.Int32);
            comm.Parameters.Add("i_name", OracleType.VarChar, 50);
            comm.Parameters.Add("cur_out", OracleType.Cursor);
            comm.Parameters[0].Value = 2;
            comm.Parameters[1].Value = this.comboBox1.SelectedValue.ToString();
            comm.Parameters[2].Direction = ParameterDirection.Output;
            OracleDataAdapter da = new OracleDataAdapter(comm);
            DataSet ds = new DataSet();
            da.Fill(ds);

　　　　conn.close();

2、轉(zhuǎn)化為圖片

if (ds.Tables[0].Rows.Count > 0)
            {
                MemoryStream buf = new MemoryStream();
                byte[] blob = (byte[])ds.Tables[0].Rows[0]["pic"];//
                buf.Write(blob, 0, blob.Length);
                Image image = Image.FromStream(buf);
                pictureBox2.Image = image;
            }

涉及到的存儲(chǔ)過程

 //create or replace procedure addUser
                //(i_name in U_INFO.NAME%type,
                // i_pic  in u_info.pic%type

                // )
                // is
                // begin
                //   insert into U_INFO(name,pic) values(i_name,i_pic);
                // end adduser;

//create or replace procedure selectUser
            //(flag in int,
            // i_name  in u_info.name%type,
            // cur_out  out  sys_refcursor
            // )
            // is
            // begin
            //  if flag=1 then
            //     open cur_out for
            //      select name from U_Info;
            //  end if;
            //  if flag=2 then
            //     open cur_out for
            //      select * from U_Info where name=i_name;
            //  end if;
            // end selectUser;

注：在此遇見的問題

 Image.FromStream(buf);這塊報(bào)參數(shù)無效

可能的原因：

1，圖片轉(zhuǎn)化為二進(jìn)制是出現(xiàn)問題，導(dǎo)致讀取的二進(jìn)制不能轉(zhuǎn)化為圖片，所以報(bào)參數(shù)無效

2，讀取時(shí)轉(zhuǎn)化出錯(cuò)，可能byte長(zhǎng)度不夠，導(dǎo)致不完整，報(bào)參數(shù)無效

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