|
SQLServer提供了一个特别的数据类型：image，它是一个包含binary数据的类型。下边这个例子就向你展示了如何将文本或照片放入到数据库中的办法。在这篇文章中我们要看到如何在SQL
Server中存储和读取图片。
1、建立一个表：
在SQLSERVER中建立这样结构的一个表：
2、存储图片到SQLSERVER数据库中
为了能存储到表中，你首先要上传它们到你的WEB服务器上，你可以开发一个webform，它用来将客户端中TextBoxwebcontrol中的图片入到你的WEB服务器上来。将你的
encType属性设置为：myltipart/formdata.
Streamimgdatastream=File1.PostedFile.InputStream;
intimgdatalen=File1.PostedFile.ContentLength;
stringimgtype=File1.PostedFile.ContentType;
stringimgtitle=TextBox1.Text;
byte[]imgdata=newbyte[imgdatalen];
intn=imgdatastream.Read(imgdata,0,imgdatalen);
stringconnstr=((NameValueCollection)Context.GetConfig("appSettings"))["connstr"];
SqlConnectionconnection=newSqlConnection(connstr);
SqlCommandcommand=newSqlCommand
("INSERTINTOImageStore(imgtitle,imgtype,imgdata)
VALUES(@imgtitle,@imgtype,@imgdata)",connection);
SqlParameterparamTitle=newSqlParameter
("@imgtitle",SqlDbType.VarChar,50);
paramTitle.Value=imgtitle;
command.Parameters.Add(paramTitle);
SqlParameterparamData=newSqlParameter("@imgdata",SqlDbType.Image
);
paramData.Value=imgdata;
command.Parameters.Add(paramData);
SqlParameterparamType=newSqlParameter("@imgtype",SqlDbType.VarChar,50
);
paramType.Value=imgtype;
command.Parameters.Add(paramType);
connection.Open();
intnumRowsAffected=command.ExecuteNonQuery();
connection.Close();
3、从数据库中恢复读取
现在让我们来从SQLServer中读取我们放入的数据吧!我们将要输出图片到你的浏览器上，你也可以将它存放到你要的位置。
privatevoidPage_Load(objectsender,System.EventArgse)
{
stringimgid=Request.QueryString["imgid"];
stringconnstr=((NameValueCollection)
Context.GetConfig("appSettings"))["connstr"];
stringsql="SELECTimgdata,imgtypeFROMImageStoreWHEREid="+imgid;
SqlConnectionconnection=newSqlConnection(connstr);
SqlCommandcommand=newSqlCommand(sql,connection);
connection.Open();
SqlDataReaderdr=command.ExecuteReader();
if(dr.Read())
{
Response.ContentType=dr["imgtype"].ToString();
Response.BinaryWrite((byte[])dr["imgdata"]);
}
connection.Close();
}
要注意的是Response.BinaryWrite而不是Response.Write.
下面给大家一个用于C#Winform的存入、读取程序。其中不同请大家自己比较!(为了方便起见，我将数据库字段简化为二个：imgtitle和imgdata。
usingSystem;
usingSystem.Drawing;
usingSystem.Collections;
usingSystem.ComponentModel;
usingSystem.Windows.Forms;
usingSystem.Data;
usingSystem.IO;
usingSystem.Data.SqlClient;
namespaceWindowsApplication21
{
///＜summary＞
///Form1的摘要说明。
///＜/summary＞
publicclassForm1:System.Windows.Forms.Form
{
privateSystem.Windows.Forms.Buttonbutton1;
///＜summary＞
///必需的设计器变量。
///＜/summary＞
privateSystem.ComponentModel.Containercomponents=null;
privatestringConnectionString="IntegratedSecurity=SSPI;Initial
Catalog=;Data Source=localhost;";
privateSqlConnectionconn=null;
privateSqlCommandcmd=null;
privateSystem.Windows.Forms.Buttonbutton2;
privateSystem.Windows.Forms.PictureBoxpic1;
privateSystem.Windows.Forms.OpenFileDialogopenFileDialog1;
privatestringsql=null;
privateSystem.Windows.Forms.Labellabel2;
privatestringnowId=null;
publicForm1()
{
//
//Windows窗体设计器支持所必需的
//
InitializeComponent();
conn=newSqlConnection(ConnectionString);
//
//TODO:在InitializeComponent调用后添加任何构造函数代码
//
}
///＜summary＞
///清理所有正在使用的资源。
///＜/summary＞
protectedoverridevoidDispose(booldisposing)
{
if(conn.State==ConnectionState.Open)
conn.Close();
if(disposing)
{
if(components!=null)
{
components.Dispose();
}
}
base.Dispose(disposing);
}
#regionWindowsFormDesignergeneratedcode
///＜summary＞
///设计器支持所需的方法-不要使用代码编辑器修改
///此方法的内容。
///＜/summary＞
privatevoidInitializeComponent()
{
this.button1=newSystem.Windows.Forms.Button();
this.pic1=newSystem.Windows.Forms.PictureBox();
this.button2=newSystem.Windows.Forms.Button();
this.openFileDialog1=newSystem.Windows.Forms.OpenFileDialog();
this.label2=newSystem.Windows.Forms.Label();
this.SuspendLayout();
//
//button1
//
this.button1.Location=newSystem.Drawing.Point(0,40);
this.button1.Name="button1";
this.button1.Size=newSystem.Drawing.Size(264,48);
this.button1.TabIndex=0;
this.button1.Text="加入新的图片";
this.button1.Click+=newSystem.EventHandler(this.button1_Click);
//
//pic1
//
this.pic1.Location=newSystem.Drawing.Point(280,8);
this.pic1.Name="pic1";
this.pic1.Size=newSystem.Drawing.Size(344,264);
this.pic1.TabIndex=3;
this.pic1.TabStop=false;
//
//button2
//
this.button2.Location=newSystem.Drawing.Point(0,104);
this.button2.Name="button2";
this.button2.Size=newSystem.Drawing.Size(264,40);
this.button2.TabIndex=4;
this.button2.Text="从数据库中恢复图像";
this.button2.Click+=newSystem.EventHandler(this.button2_Click);
//
//openFileDialog1
//
this.openFileDialog1.Filter="\"图像文件(*.jpg,*.bmp,*.gif)|*.jpg|*.bmp|*.gif\"";
//
//label2
//
this.label2.Location=newSystem.Drawing.Point(0,152);
this.label2.Name="label2";
this.label2.Size=newSystem.Drawing.Size(264,48);
this.label2.TabIndex=5;
//
//Form1
//
this.AutoScaleBaseSize=newSystem.Drawing.Size(6,14);
this.ClientSize=newSystem.Drawing.Size(632,273);
this.Controls.AddRange(newSystem.Windows.Forms.Control[]{
this.label2,
this.button2,
this.pic1,
this.button1});
this.Name="Form1";
this.Text="Form1";
this.Load+=newSystem.EventHandler(this.Form1_Load);
this.ResumeLayout(false);
}
#endregion
///＜summary＞
///应用程序的主入口点。
///＜/summary＞
[STAThread]
staticvoidMain()
{
Application.Run(newForm1());
}
privatevoidbutton1_Click(objectsender,System.EventArgse)
{
openFileDialog1.ShowDialog();
if(openFileDialog1.FileName.Trim()!="")
{
FileInfofi=newFileInfo(openFileDialog1.FileName);
stringimgtitle=openFileDialog1.FileName;
intimgdatalen=(int)fi.Length;
byte[]imgdata=newbyte[imgdatalen];
Streamimgdatastream=fi.OpenRead();
intn=imgdatastream.Read(imgdata,0,imgdatalen);
if(conn.State==ConnectionState.Open)
conn.Close();
ConnectionString="IntegratedSecurity=SSPI;"+"InitialCatalog=mydb;"+"Data
Source=localhost;";
conn.ConnectionString=ConnectionString;
try
{
stringmySelectQuery="INSERTINTOImageStore(imgtitle,imgdata)VALUES
(@imgtitle,@imgdata)";
//stringmySelectQuery="UPDATEImageStoresetimgtitle=@imgtitle,imgdata=@imgdata";
SqlCommandmyCommand=newSqlCommand(mySelectQuery,conn);
SqlParameterparamTitle=newSqlParameter("@imgtitle",SqlDbType.VarChar,50
);
paramTitle.Value=imgtitle;
myCommand.Parameters.Add(paramTitle);
SqlParameterparamData=newSqlParameter("@imgdata",SqlDbType.Image
);
paramData.Value=imgdata;
myCommand.Parameters.Add(paramData);
conn.Open();
intnumRowsAffected=myCommand.ExecuteNonQuery();
conn.Close();
}
catch(Exceptionerr)
{
MessageBox.Show("您输入名称可能在数据库中已存在或输入为空，请检查!"+err.ToString());
}
finally
{}
}
}
privatevoidForm1_Load(objectsender,System.EventArgse)
{
}
privatevoidbutton2_Click(objectsender,System.EventArgse)
{
//打开数据库连接
if(conn.State==ConnectionState.Open)
conn.Close();
ConnectionString="IntegratedSecurity=SSPI;"+"InitialCatalog=mydb;"+"Data
Source=localhost;";
conn.ConnectionString=ConnectionString;
//创建数据适配器
stringsql="SELECT*FROMImageStore";
SqlCommandcommand=newSqlCommand(sql,conn);
try
{conn.Open();}
catch(Exceptionnewerr)
{
MessageBox.Show("不能打开数据联接!");
}
finally
{}
SqlDataReaderdr=command.ExecuteReader();
if(dr.Read())
{
FileInfofi=newFileInfo("temp");
FileStreammyStream=fi.Open(FileMode.Create);
byte[]mydata=((byte[])dr["imgdata"]);
//label2.Text="您现在看到的是："+dr["imgtitle"].ToString();
foreach(byteainmydata)
{
myStream.WriteByte(a);
}
myStream.Close();
ImagemyImage=Image.FromFile("temp");
pic1.Image=myImage;
pic1.Refresh();
dr.Close();
}
else
{
MessageBox.Show("没有成功读入数据!");
}
conn.Close();
}
}
}
|
当前位置：
