c#从sql中读取和存入图片

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1、C#从SQL数据库中读取和存入图片本实例主要介绍如何将图片存入数据库。将图片存入数据库,首先要在数据库中建立一张表,将存储图片的字段类型设为Image类型,用FileStream类、BinaryReader把图片读成字节的形式,赋给一个字节数组,然后用ADO.SqlCommand对象的ExecuteNonQuery()方法来把数据保存到数据库中。主要代码如下：   privatevoidbutton1_Click(objectsender,EventArgse)       {         openFileDialog1.Filter="*jpg

2、*.JPG

3、*.GIF

4、*.GIF

5、*.

6、BMP

7、*.BMP";           if(openFileDialog1.ShowDialog()==DialogResult.OK)           {             stringfullpath=openFileDialog1.FileName;//文件路径             FileStreamfs=newFileStream(fullpath,FileMode.Open);               byte[]imagebytes=newbyte[fs.Length];               BinaryReaderbr=newBinaryRea

8、der(fs);               imagebytes=br.ReadBytes(Convert.ToInt32(fs.Length));               //打开数据库               SqlConnectioncon=newSqlConnection("server=(local);uid=sa;pwd=;database=db_05");               con.Open();               SqlCommandcom=newSqlCommand("insertintotb_08values(@ImageList)",con

9、);               com.Parameters.Add("ImageList",SqlDbType.Image);               com.Parameters["ImageList"].Value=imagebytes;              com.ExecuteNonQuery();              con.Close();            }    }本实例主要介绍如何从数据库中把图片读出来。实现本实例主要是利用SqlDataReader从数据库中把Image字段值读出来，赋给一个byte[]字节数组，然后使用MemoryStream类

10、与Bitmap把图片读取出来。主要代码如下：   privatevoidbutton1_Click(objectsender,EventArgse)       {                byte[]imagebytes=null;               //打开数据库           SqlConnectioncon=newSqlConnection("server=(local);uid=sa;pwd=;database=db_05");               con.Open();               SqlCommandcom=newSqlComman

11、d("selecttop1*fromtb_09",con);               SqlDataReaderdr=com.ExecuteReader();               while(dr.Read())               {                   imagebytes=(byte[])dr.GetValue(1);               }               dr.Close();               com.Clone();               con.Close();               MemoryS

12、treamms=newMemoryStream(imagebytes);               Bitmapbmpt=newBitmap(ms);               pictureBox1.Image=bmpt;       }本实例主要介绍如何只允许输入指定图片格式。用OpenFileDialog控件打开图片文件，只要将OpenFileDialog控件的Filter属性指定为特定的图片格式即