c#操作sql中存取图片image

c#在sql数据库中存取图片image示例。

（1）控制台应用程序下演示插入图片

复制代码代码如下:

public void InsertIMG()

{

//将需要存储的图片读取为数据流

FileStream fs = new FileStream(@"E:\c.jpg", FileMode.Open,FileAccess.Read);

Byte[] btye2 = new byte[fs.Length];

fs.Read(btye2 , 0, Convert.ToInt32(fs.Length));

fs.Close();

using (SqlConnection conn = new SqlConnection(sqlconnstr))

{

conn.Open();

SqlCommand cmd = new SqlCommand();

cmd.Connection = conn;

cmd.CommandText = "insert into T_Img(imgfile) values(@imgfile)";

SqlParameter par = new SqlParameter("@imgfile", SqlDbType.Image);

par.Value = bt;

cmd.Parameters.Add(par);

int t=(int)(cmd.ExecuteNonQuery());

if (t > 0)

{

Console.WriteLine("插入成功");

}

conn.Close();

}

}

（2）控制台应用程序下读出并生成图片到物理位置

复制代码代码如下:

public void Read()

{

byte[] MyData = new byte[0];

using (SqlConnection conn = new SqlConnection(sqlconnstr))

{ // www.jbxue.com

conn.Open();

SqlCommand cmd = new SqlCommand();

cmd.Connection = conn;

cmd.CommandText = "select * from T_img";

SqlDataReader sdr = cmd.ExecuteReader();

sdr.Read();

MyData = (byte[])sdr["ImgFile"];//读取第一个图片的位流

int ArraySize= MyData.GetUpperBound(0);//获得数据库中存储的位流数组的维度上限，用作读取流的上限

FileStream fs = new FileStream(@"c:\00.jpg", FileMode.OpenOrCreate, FileAccess.Write);

fs.Write(MyData, 0, ArraySize);

fs.Close(); //-- 写入到c:\00.jpg。

conn.Close();

Console.WriteLine("读取成功");//查看硬盘上的文件

}

}

（3）Web下picshow.aspx页将图片读取出来并写入到浏览器上呈现

复制代码代码如下:

public void Read()

{ // www.jbxue.com

byte[] MyData = new byte[0];

using (SqlConnection conn = new SqlConnection(sqlconnstr))

{

conn.Open();

SqlCommand cmd = new SqlCommand();

cmd.Connection = conn;

cmd.CommandText = "select * from T_img";

SqlDataReader sdr = cmd.ExecuteReader();

sdr.Read();

MyData = (byte[])sdr["ImgFile"];

Response.ContentType = "image/gif";

Response.BinaryWrite(MyData);

conn.Close();

Response.Write("读取成功");

}

（4）在web中可以如上picshow.aspx页面读取并显示图片，而真正引用该图片时如下示例

复制代码代码如下:

<img src="picshow.aspx" width="500" height="300" />

（5）Winform下将图片写入到sql数据库image类型字段中的方法和以上方法基本一致，仅区别于可以利用多个对话框来帮助选取存储图片等，各个属性可以方便的利用上

（6）Winform下读取图片在picturebox控件中显示出来

方法一：利用MemoryStream 和System.Drawing.Image

复制代码代码如下:

public void Read()

{

byte[] MyData = new byte[0];

using (SqlConnection conn = new SqlConnection(sqlconnstr))

{

conn.Open();

SqlCommand cmd = new SqlCommand();

cmd.Connection = conn;

cmd.CommandText = "select * from T_img";

SqlDataReader sdr = cmd.ExecuteReader();

sdr.Read();

MyData = (byte[])sdr["ImgFile"];

MemoryStream mystream = new MemoryStream(MyData);

//用指定的数据流来创建一个image图片

System.Drawing.Image img = System.Drawing.Image.FromStream(mystream, true);

System.Windows.Forms.PictureBox picbox = new PictureBox();

picbox.Image = img;

picbox.Left = 30;

picbox.Top = 80;

picbox.Width = 800;

picbox.Height = 500;

this.Controls.Add(picbox);

mystream.Close();

conn.Close();

}

}

方法二：将流直接读取成图片并写入到物理位置，然后再行利用该图片呈现

复制代码代码如下:

void Read()

{

using (SqlConnection conn = new SqlConnection(sqlconnstr))

{

conn.Open();

SqlCommand cmd = new SqlCommand();

cmd.Connection = conn;

cmd.CommandText = "select * from T_img";

SqlDataReader sdr = cmd.ExecuteReader();

sdr.Read();

byte[] Image_img = (byte[])sdr["ImgFile"];

if (Image_img.Length == 0)

{

return;

} // www.jbxue.com

int filelength = Image_img.Length;

string imageName = "1.jpg";

string myUrl = Environment.CurrentDirectory + "\\" + imageName;

FileStream fs = new FileStream(myUrl, FileMode.OpenOrCreate,FileAccess.Write);

BinaryWriter BW = new BinaryWriter(fs);

BW.BaseStream.Write(Image_img, 0, filelength);

BW.Flush();

BW.Close();

System.Windows.Forms.PictureBox picbox = new PictureBox();

//为picbox添加图片方法一

//picbox.ImageLocation = myUrl;

//picbox.Width = 800;

//picbox.Height = 300;

//为picbox添加图片方法二

Bitmap bitmap = new Bitmap(myUrl);

picbox.Width = 100;//bitmap.Width;

picbox.Height = 80;//bitmap.Height;

picbox.Image = (Image)bitmap;

picbox.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;

picbox.Left = 20;

picbox.Top = 30;

this.Controls.Add(picbox);

conn.Close();

}

}