Asp.net把图片存入数据库和使用文件流来读取显示

一、数据库存储图片类型有以下几种方式：

1、将图片装换为二进制数值(byte[])

byte [] fileData=this.FileUpload1.FileBytes;

2、根据路径将文件装换为二进制数组

private byte[] returnbyte(string strpath)

{

//以二进制方式读文件

FileStream fsMyfile = new FileStream(strpath, FileMode.OpenOrCreate, FileAccess.ReadWrite);

//创建一个二进制数据流读入器，和打开的文件关联

BinaryReader brMyfile = new BinaryReader(fsMyfile);

//把文件指针重新定位到文件的开始

brMyfile.BaseStream.Seek(0, SeekOrigin.Begin);

byte[] bytes = brMyfile.ReadBytes(Convert.ToInt32(fsMyfile.Length.ToString()));

//关闭以上的new的各个对象

brMyfile.Close();

return bytes;

}

3、Image类型得到二进制数组

public static byte[] Getbyte(Image img)

{

MemoryStream stream = new MemoryStream();

img.Save(stream, ImageFormat.Jpeg); //Image.FromFile(Path).Save(stream, ImageFormat.Jpeg); ;

byte[] mydata = new byte[stream.Length];

mydata = stream.ToArray();

stream.Close();

return mydata;

}

二、图片的显示

读取image类型的数据并显示在网页上的方式如下

1、直接返回image类型

private System.Drawing.Image GetImageDataFromDB()

{

string sql = "select Picture from TPicture where ID=1";

string strconn = System.Configuration.ConfigurationManager.ConnectionStrings["Conn"].ToString();

SqlConnection conn = new SqlConnection(strconn);

SqlCommand cmd = new SqlCommand(sql, conn);

conn.Open();

byte[] filedata = (byte[])cmd.ExecuteScalar();

conn.Close();

System.IO.MemoryStream ms = new MemoryStream(filedata);

System.Drawing.Image img = System.Drawing.Image.FromStream(ms);

return img;

}

2、利用页面输出来显示图片

页面ShowImage.aspx(Page_Load)方法

protected void Page_Load(object sender, EventArgs e)

{

string sql = "select Picture from TPicture";

string strconn = System.Configuration.ConfigurationManager.ConnectionStrings["Conn"].ToString();

SqlConnection conn = new SqlConnection(strconn);

SqlDataAdapter da = new SqlDataAdapter(sql, conn);

DataTable dt = new DataTable();

da.Fill(dt);

byte[] logoimg = (byte[])dt.Rows[0]["Picture"];

if (logoimg.Length > 0)

{

System.Drawing.Image img;

MemoryStream ms = new MemoryStream(logoimg);

Response.Clear();

Response.ContentType = "image/gif";

Response.OutputStream.Write(logoimg, 0, logoimg.Length);

Response.End();

}

}

图片路径写为：<img src="ShowImage.aspx" />

图片在数据库中的类型设置为image类型

示例：

SqlConnection conn = new SqlConnection(strconn);

conn.Open();

string sql = "insert into TPicture(Picture) values(@Picture)";

SqlCommand cmd = new SqlCommand(sql, conn);

SqlParameter para = new SqlParameter("@Picture", SqlDbType.Image);

//para.Value = FileUpload1.FileBytes;

para.Value = Getbyte(null);//字节数组

cmd.Parameters.Add(para);

cmd.ExecuteNonQuery();