从文件中加载二进制图像数据
// 从文件中加载二进制图像数据
// LoadImages.cs
// 在C#程序中，二进制数据类型映射为字节数据(byet[])，
// 字符数据类型映射为字符串或者字符数组(char[])
using System;
using System.Data;
using System.Data.SqlClient;
using System.IO;
namespace Ch18
{
class LoadImages
{
// 假设图片文件使用 image1.jpg、image2.jpg..imageX.jpg命名规则存放在当前目录的pic目录下
string imgPath = ".\\pic\\" ;
string imgPrefix = "image";
int fileNumber = 3;
string imgType = ".jpg";
int maxImageSize = 10000;
SqlConnection conn = null;
SqlCommand cmd = null;
static void Main()
{
LoadImages loader = new LoadImages();
try
{
loader.OpenConnection();
loader.CreateCommand();
loader.CreateImageTable();
loader.PrepareInsertImages();
int i;
for (i = 1; i <= loader.fileNumber; i++)
{
loader.ExecuteInsertImages(i);
}
}
catch(SqlException ex)
{
Console.WriteLine(ex.ToString());
}
finally
{
loader.CloseConnection();
Console.WriteLine("博客园首发");
Console.ReadLine();
}
}
void OpenConnection()
{
string strConn = "server=.\\MSSQL2012;integrated security = true; database=tempdb";
conn = new SqlConnection(strConn);
conn.Open();
}
void CloseConnection()
{
conn.Close();
Console.WriteLine( "连接关闭" );
}
void CreateCommand()
{
cmd = new SqlCommand();
cmd.Connection = conn;
}
void ExecuteCommand( string cmdText)
{
int cmdResult;
cmd.CommandText = cmdText;
Console.WriteLine( "执行SQL:");
Console.WriteLine(cmd.CommandText);
cmdResult = cmd.ExecuteNonQuery();
}
void CreateImageTable()
{
ExecuteCommand( @"create table imagetable(imagefile nvarchar(20), imagedata varbinary(max))");
}
void PrepareInsertImages()
{
cmd.CommandText = @"insert into imagetable values(@file,@data)";
cmd.Parameters.Add( "@file", SqlDbType.NVarChar, 20);
cmd.Parameters.Add( "@data", SqlDbType.Image, 1000000);
cmd.Prepare();
}
void ExecuteInsertImages( int fileNo)
{
string strFile = null;
byte[] imgData = null;
strFile = imgPrefix + fileNo.ToString() + imgType;
imgData = LoadImageFile(strFile, imgPath, maxImageSize);
cmd.Parameters[ "@file"].Value = strFile;
cmd.Parameters[ "@data"].Value = imgData;
ExecuteCommand(cmd.CommandText);
}
byte[] LoadImageFile( string strFile, string strPath, int iSize)
{
byte[] imageBytes = null;
string strFullPath = strPath + strFile;
Console.WriteLine( "加载文件:" );
Console.WriteLine(strFullPath);
FileStream fs = new FileStream(strFullPath, FileMode.Open, FileAccess.Read);
BinaryReader br = new BinaryReader (fs);
imageBytes = br.ReadBytes(iSize);
Console.WriteLine( "Imagebytes has length {0} bytes." , imageBytes.GetLength(0));
return imageBytes;
}
}
}
------------
执行SQL:
create table imagetable(imagefile nvarchar(20), imagedata varbinary(max))
加载文件:
.\pic\image1.jpg
Imagebytes has length 10000 bytes.
执行SQL:
insert into imagetable values(@file,@data)
加载文件:
.\pic\image2.jpg
Imagebytes has length 10000 bytes.
执行SQL:
insert into imagetable values(@file,@data)
加载文件:
.\pic\image3.jpg
Imagebytes has length 10000 bytes.
执行SQL:
insert into imagetable values(@file,@data)
连接关闭
