参考：http://www.cnblogs.com/yuanbao/archive/2007/09/25/905322.html
using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
namespace BallotAiying2
{
class UnCodebase
{
public Bitmap bmpobj;
public UnCodebase(Bitmap pic)
{
bmpobj = new Bitmap(pic); //转换为Format32bppRgb
}
/// <summary>
/// 根据RGB，计算灰度值
/// </summary>
/// <param name="posClr">Color值</param>
/// <returns>灰度值，整型</returns>
private int GetGrayNumColor(System.Drawing.Color posClr)
{
return (posClr.R * 19595 + posClr.G * 38469 + posClr.B * 7472) >> 16;
}
/// <summary>
/// 灰度转换,逐点方式
/// </summary>
public void GrayByPixels()
{
for (int i = 0; i < bmpobj.Height; i++)
{
for (int j = 0; j < bmpobj.Width; j++)
{
int tmpValue = GetGrayNumColor(bmpobj.GetPixel(j, i));
bmpobj.SetPixel(j, i, Color.FromArgb(tmpValue, tmpValue, tmpValue));
}
}
}
/// <summary>
/// 去图形边框
/// </summary>
/// <param name="borderWidth"></param>
public void ClearPicBorder(int borderWidth)
{
for (int i = 0; i < bmpobj.Height; i++)
{
for (int j = 0; j < bmpobj.Width; j++)
{
if (i < borderWidth || j < borderWidth || j > bmpobj.Width - 1 - borderWidth || i > bmpobj.Height - 1 - borderWidth)
bmpobj.SetPixel(j, i, Color.FromArgb(255, 255, 255));
}
}
}
/// <summary>
/// 灰度转换,逐行方式
/// </summary>
public void GrayByLine()
{
Rectangle rec = new Rectangle(0, 0, bmpobj.Width, bmpobj.Height);
BitmapData bmpData = bmpobj.LockBits(rec, ImageLockMode.ReadWrite, bmpobj.PixelFormat);// PixelFormat.Format32bppPArgb);
// bmpData.PixelFormat = PixelFormat.Format24bppRgb;
IntPtr scan0 = bmpData.Scan0;
int len = bmpobj.Width * bmpobj.Height;
int[] pixels = new int[len];
Marshal.Copy(scan0, pixels, 0, len);
//对图片进行处理
int GrayValue = 0;
for (int i = 0; i < len; i++)
{
GrayValue = GetGrayNumColor(Color.FromArgb(pixels[i]));
pixels[i] = (byte)(Color.FromArgb(GrayValue, GrayValue, GrayValue)).ToArgb(); //Color转byte
}
bmpobj.UnlockBits(bmpData);
}
/// <summary>
/// 得到有效图形并调整为可平均分割的大小
/// </summary>
/// <param name="dgGrayValue">灰度背景分界值</param>
/// <param name="CharsCount">有效字符数</param>
/// <returns></returns>
public void GetPicValidByValue(int dgGrayValue, int CharsCount)
{
int posx1 = bmpobj.Width; int posy1 = bmpobj.Height;
int posx2 = 0; int posy2 = 0;
for (int i = 0; i < bmpobj.Height; i++) //找有效区
{
for (int j = 0; j < bmpobj.Width; j++)
{
int pixelValue = bmpobj.GetPixel(j, i).R;
if (pixelValue < dgGrayValue) //根据灰度值
{
if (posx1 > j) posx1 = j;
if (posy1 > i) posy1 = i;
if (posx2 < j) posx2 = j;
if (posy2 < i) posy2 = i;
};
};
};
// 确保能整除
int Span = CharsCount - (posx2 - posx1 + 1) % CharsCount; //可整除的差额数
if (Span < CharsCount)
{
int leftSpan = Span / 2; //分配到左边的空列 ，如span为单数,则右边比左边大1
if (posx1 > leftSpan)
posx1 = posx1 - leftSpan;
if (posx2 + Span - leftSpan < bmpobj.Width)
posx2 = posx2 + Span - leftSpan;
}
//复制新图
Rectangle cloneRect = new Rectangle(posx1, posy1, posx2 - posx1 + 1, posy2 - posy1 + 1);
bmpobj = bmpobj.Clone(cloneRect, bmpobj.PixelFormat);
}
/// <summary>
/// 得到有效图形,图形为类变量
/// </summary>
/// <param name="dgGrayValue">灰度背景分界值</param>
/// <param name="CharsCount">有效字符数</param>
/// <returns></returns>
public void GetPicValidByValue(int dgGrayValue)
{
int posx1 = bmpobj.Width; int posy1 = bmpobj.Height;
int posx2 = 0; int posy2 = 0;
for (int i = 0; i < bmpobj.Height; i++) //找有效区
{
for (int j = 0; j < bmpobj.Width; j++)
{
int pixelValue = bmpobj.GetPixel(j, i).R;
if (pixelValue < dgGrayValue) //根据灰度值
{
if (posx1 > j) posx1 = j;
if (posy1 > i) posy1 = i;
if (posx2 < j) posx2 = j;
if (posy2 < i) posy2 = i;
};
};
};
//复制新图
Rectangle cloneRect = new Rectangle(posx1, posy1, posx2 - posx1 + 1, posy2 - posy1 + 1);
bmpobj = bmpobj.Clone(cloneRect, bmpobj.PixelFormat);
}
/// <summary>
/// 得到有效图形,图形由外面传入
/// </summary>
/// <param name="dgGrayValue">灰度背景分界值</param>
/// <param name="CharsCount">有效字符数</param>
/// <returns></returns>
public Bitmap GetPicValidByValue(Bitmap singlepic, int dgGrayValue)
{
int posx1 = singlepic.Width; int posy1 = singlepic.Height;
int posx2 = 0; int posy2 = 0;
for (int i = 0; i < singlepic.Height; i++) //找有效区
{
for (int j = 0; j < singlepic.Width; j++)
{
int pixelValue = singlepic.GetPixel(j, i).R;
if (pixelValue < dgGrayValue) //根据灰度值
{
if (posx1 > j) posx1 = j;
if (posy1 > i) posy1 = i;
if (posx2 < j) posx2 = j;
if (posy2 < i) posy2 = i;
};
};
};
//复制新图
Rectangle cloneRect = new Rectangle(posx1, posy1, posx2 - posx1 + 1, posy2 - posy1 + 1);
return singlepic.Clone(cloneRect, singlepic.PixelFormat);
}
/// <summary>
/// 平均分割图片
/// </summary>
/// <param name="RowNum">水平上分割数</param>
/// <param name="ColNum">垂直上分割数</param>
/// <returns>分割好的图片数组</returns>
public Bitmap [] GetSplitPics(int RowNum,int ColNum)
{
if (RowNum == 0 || ColNum == 0)
return null;
int singW = bmpobj.Width / RowNum;
int singH = bmpobj.Height / ColNum;
Bitmap [] PicArray=new Bitmap[RowNum*ColNum];
Rectangle cloneRect;
for (int i = 0; i < ColNum; i++) //找有效区
{
for (int j = 0; j < RowNum; j++)
{
cloneRect = new Rectangle(j*singW, i*singH, singW , singH);
PicArray[i*RowNum+j]=bmpobj.Clone(cloneRect, bmpobj.PixelFormat);//复制小块图
}
}
return PicArray;
}
/// <summary>
/// 返回灰度图片的点阵描述字串，1表示灰点，0表示背景
/// </summary>
/// <param name="singlepic">灰度图</param>
/// <param name="dgGrayValue">背前景灰色界限</param>
/// <returns></returns>
public string GetSingleBmpCode(Bitmap singlepic, int dgGrayValue)
{
Color piexl;
string code = "";
for (int posy = 0; posy < singlepic.Height; posy++)
for (int posx = 0; posx < singlepic.Width; posx++)
{
piexl = singlepic.GetPixel(posx, posy);
if (piexl.R < dgGrayValue) // Color.Black )
code = code + "1";
else
code = code + "0";
}
return code;
}
}
}
月度归档： 2012年1月
web.config中poolsize与mssql中的connection
web.config中的 max poolsize指的是保存的与数据库连接的个数，由.net维护，常报的“超时时间已到，但是尚未从池中获取连接。出现这种情况可能是因为所有池连接均在使用，并且达到了最大池大小。 ”指的是连接数超出了max pool size引起。
连接池中的连接与mssql中的sys.dm_exec_connections中是对应的，不过sys.dm_exec_connections的连接也包含其他连接，故总数是>=pool size中的连接数量的。
可以在sys.dm_exec_connections中通过web.config连接的用户名来查询目前web.config连接了多少个：
SELECT a.most_recent_sql_handle,COUNT(1) d FROM
sys.dm_exec_connections a
JOIN sys.dm_exec_sessions b ON a.session_id = b.session_id AND b.login_name=’brm’
GROUP BY a.most_recent_sql_handle
ORDER BY d DESC
死循环引起的连接池耗尽
用户反应系统响应慢，报连接池超过最大连接数错误，上去看服务器，CPU，内存都很正常。过一段时间系统又自动恢复。通过以下方法排查连接数：
sp_configure ‘user connections’
—-查看系统连接数：
SELECT d.name,b.login_name,COUNT(1) ccount,m.text FROM
sys.dm_exec_connections a
JOIN sys.dm_exec_sessions b ON a.session_id = b.session_id –AND b.login_name IN('OA','brm')
JOIN sys.databases d ON b.database_id = d.database_id
cross apply sys.dm_exec_sql_text(a.most_recent_sql_handle)m
GROUP BY d.name,b.login_name,m.text
ORDER BY d.name,b.login_name,ccount DESC
—-或者看明细
SELECT b.session_id,d.name,b.login_name,m.text,
a.client_net_address,a.connect_time,a.last_read,a.last_write
FROM sys.dm_exec_connections a
JOIN sys.dm_exec_sessions b ON a.session_id = b.session_id –AND b.login_name IN('OA','brm')
JOIN sys.databases d ON b.database_id = d.database_id
cross apply sys.dm_exec_sql_text(a.most_recent_sql_handle)m
where client_net_address != '<local machine>'
order by a.last_read desc
发现排在第一位的连接数景有数千，意味着一个会话内发生了上千次的连接，这是很异常的，分析sql语句来源定位异常sql语句：
SELECT * FROM sys.dm_exec_sql_text(0x03000600B1C9EA687B3F2801CA9F00000100000000000000)
–看sql语句
SELECT TOP 50
qs.total_worker_time/qs.execution_count/1000. as [平均消耗CPU 时间(ms)],
total_worker_time/1000 AS [总消耗CPU 时间(ms)],execution_count [运行次数],
SUBSTRING(qt.text,qs.statement_start_offset/2+1,
(case when qs.statement_end_offset = -1
then DATALENGTH(qt.text)
else qs.statement_end_offset end -qs.statement_start_offset)/2 + 1)
as [查询语句], qt.text [所在存储过程],
qt.dbid, dbname=db_name(qt.dbid),
qt.objectid,object_name(qt.objectid,qt.dbid) ObjectName
FROM sys.dm_exec_query_stats qs
cross apply sys.dm_exec_sql_text(qs.sql_handle) as qt
WHERE qs.last_execution_time >=’2012-01-10 10:00′ AND dbid = 6
AND qs.sql_handle = ’0x03000600B1C9EA687B3F2801CA9F00000100000000000000′
发现最大连接数为596，599？