博客园-sky266

asp.net mvc preview 5发布.

暗香浮动 — Wed, 03 Sep 2008 06:52:00 GMT

http://weblogs.asp.net/scottgu/archive/2008/09/02/asp-net-mvc-preview-5-and-form-posting-scenarios.aspx

连接地址.

移除字符串末尾制定个数字符

暗香浮动 — Mon, 11 Aug 2008 01:07:00 GMT

移除StringBuilder 末尾制定个数的字符，以前都是适用下面的方法做的

            StringBuilder sb = new StringBuilder();
            sb.Append("abcd");
            sb.Remove(sb.Length - 3, 3);
            Console.Write(sb.ToString());
            Console.Read();

其实有更简单的方法的。设定StringBuilder 的长度就ok了。

            StringBuilder sb = new StringBuilder();
            sb.Append("abcd");
            sb.Length--;
            Console.Write(sb.ToString());
            Console.Read();

注意string类型的length是只读的。所以不能采用该方法。

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vs使用正则替换复杂代码段

暗香浮动 — Thu, 31 Jul 2008 08:30:00 GMT

因为项目把抛到客户端的异常信息处理统一放在了基类里面处理

需要把项目中这类的代码
try
            {
                User user = UserDTOMapper.MapFromDTO(userdto);
                msg.Result = DepartmentManager.IsInDepartment(departmentid, user);
                msg.Message = msg.Result ? Resources.OperationSuccessful : Resources.OperationFailur;

            }
            catch (CustomerException e)
            {
                msg.Message = e.Message;
                msg.Result = false;
            }

成为这个
                User user = UserDTOMapper.MapFromDTO(userdto);
                msg.Result = DepartmentManager.IsInDepartment(departmentid, user);
                msg.Message = msg.Result ? Resources.OperationSuccessful : Resources.OperationFailur;

使用了一下vs的正则表达式替换。还真不错。

try[ \n]*\{{[:a. \=;\n\:\?\\,)$]*}[ }\n]*catch[ ]*\(CustomerException [e|ce]$[\n][ {]*[ \n]*[:a. \=;\n]*\}

红色这部分在替换的地方使用 \1即可。

发现竟然会写正则了。这个可能写的还有点繁琐。先用吧，以后用得多了就熟练了。

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EEheap sos

暗香浮动 — Mon, 07 Jul 2008 05:32:00 GMT

-------------------------------------------------------------------------------
!EEHeap [-gc] [-loader]

!EEHeap enumerates process memory consumed by internal CLR data structures. You

can limit the output by passing "-gc" or "-loader". All information will be

displayed otherwise.

The information for the Garbage Collector lists the ranges of each Segment in

the managed heap. This can be useful if you believe you have an object pointer.

If the pointer falls within a segment range given by "!EEHeap -gc", then you do

have an object pointer, and can attempt to run "!DumpObj" on it.

Here is output for a simple program:

0:000> !eeheap -gc

Number of GC Heaps: 1

generation 0 starts at 0x00a71018

generation 1 starts at 0x00a7100c

generation 2 starts at 0x00a71000

segment begin allocated size

00a70000 00a71000 00a7e01c 0000d01c(53276)

Large object heap starts at 0x01a71000

segment begin allocated size

01a70000 01a71000 01a76000 0x00005000(20480)

Total Size 0x1201c(73756)

------------------------------

GC Heap Size 0x1201c(73756)

So the total size of the GC Heap is only 72K. On a large web server, with

multiple processors, you can expect to see a GC Heap of 400MB or more. The

Garbage Collector attempts to collect and reclaim memory only when required to

by memory pressure for better performance. You can also see the notion of

"generations," wherein the youngest objects live in generation 0, and

long-lived objects eventually get "promoted" to generation 2.

The loader output lists various private heaps associated with AppDomains. It

also lists heaps associated with the JIT compiler, and heaps associated with

Modules. For example:

0:000> !EEHeap -loader

Loader Heap:

--------------------------------------

System Domain: 5e0662a0

LowFrequencyHeap:008f0000(00002000:00001000) Size: 0x00001000 bytes.

HighFrequencyHeap:008f2000(00008000:00001000) Size: 0x00001000 bytes.

StubHeap:008fa000(00002000:00001000) Size: 0x00001000 bytes.

Total size: 0x3000(12288)bytes

--------------------------------------

Shared Domain: 5e066970

LowFrequencyHeap:00920000(00002000:00001000) 03e30000(00010000:00003000) Size: 0x00004000 bytes.

Wasted: 0x00001000 bytes.

HighFrequencyHeap:00922000(00008000:00001000) Size: 0x00001000 bytes.

StubHeap:0092a000(00002000:00001000) Size: 0x00001000 bytes.

Total size: 0x6000(24576)bytes

--------------------------------------

Domain 1: 14f000

LowFrequencyHeap:00900000(00002000:00001000) 03ee0000(00010000:00003000) Size: 0x00004000 bytes.

Wasted: 0x00001000 bytes.

HighFrequencyHeap:00902000(00008000:00003000) Size: 0x00003000 bytes.

StubHeap:0090a000(00002000:00001000) Size: 0x00001000 bytes.

Total size: 0x8000(32768)bytes

--------------------------------------

Jit code heap:

Normal JIT:03ef0000(00010000:00002000) Size: 0x00002000 bytes.

Total size: 0x2000(8192)bytes

--------------------------------------

Module Thunk heaps:

Module 5ba22410: Size: 0x00000000 bytes.

Module 001c1320: Size: 0x00000000 bytes.

Module 001c03f0: Size: 0x00000000 bytes.

Module 001caa38: Size: 0x00000000 bytes.

Total size: 0x0(0)bytes

--------------------------------------

Module Lookup Table heaps:

Module 5ba22410:Size: 0x00000000 bytes.

Module 001c1320:Size: 0x00000000 bytes.

Module 001c03f0:Size: 0x00000000 bytes.

Module 001caa38:03ec0000(00010000:00002000) Size: 0x00002000 bytes.

Total size: 0x2000(8192)bytes

--------------------------------------

Total LoaderHeap size: 0x15000(86016)bytes

=======================================

By using !EEHeap to keep track of the growth of these private heaps, we are

able to rule out or include them as a source of a memory leak.

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jquery初接触

暗香浮动 — Thu, 28 Feb 2008 08:36:00 GMT

select 操作
获取所选值 $("#id").val()
清空 empty();
添加项 $("")

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is and as

暗香浮动 — Mon, 24 Dec 2007 11:46:00 GMT

今天看communicaty 的代码的时候发现了下面这段代码。似乎有点味道。
public T GetDataItem() where T : class
        {
            if (this.Weblog is T)
                return this.Weblog as T;
            else
                return null;
        }
难道有什么深意，如下这么些似乎更好一些。
public T GetDataItem() where T : class
        {
            return this.Weblog as T;
        }

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编程规范，try catch 和返回值的问题

暗香浮动 — Wed, 12 Dec 2007 04:28:00 GMT

自从理解了try catch机制后就有意无意的注意一下优秀的开源软件是如何处理异常捕获和返回值的问题的

下面这段是community server 上的一段代码。
想研究一下他的异常处理机制

Code
        public static bool SendMessage(MailMessage message)
        {
            try
            {
                CSContext context = CSContext.Current;

                // Replace any LF characters with CR LF
                message.Body = message.Body.Replace("\r", string.Empty);
                message.Body = message.Body.Replace("\n", "\r\n");

                // Set the encoding
                message.SubjectEncoding = Encoding.GetEncoding(context.SiteSettings.EmailSubjectEncoding);
                message.BodyEncoding = Encoding.GetEncoding(context.SiteSettings.EmailEncoding);

                // Set the content base
                message.Headers["Content-Base"] = context.SiteSettings.SiteUrl;
                message.Headers["Content-Location"] = context.SiteSettings.SiteUrl;

                // Send it
                GetSmtpClient().Send(message);
                return true;
            }
            catch (Exception e)
            {
                Debug.WriteLine(e.Message + " : " + (e.InnerException != null ? e.InnerException.Message : String.Empty));
                CSException fe;
                    if(message != null && message.To != null)
                    fe = new CSException(CSExceptionType.EmailUnableToSend, "SendMessage Failed To: " + message.To, (e.InnerException != null ? e.InnerException : e));
                    else
                    fe = new CSException(CSExceptionType.EmailUnableToSend, "SendMessage Failed Either Message or To was null: ", (e.InnerException != null ? e.InnerException : e));
                fe.Log(CSContext.Current.SiteSettings.SettingsID);
                return false;
            }
        }

这里的处理比较特殊再try catch内部返回bool型的值。跟踪了一下这个方法的调用发现使用这个方法的地方存在bool判断。这里不便依靠抛出异常来处理。这么处理放到更方便一些。

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asp.net 2.0的开源项目收集

暗香浮动 — Thu, 08 Nov 2007 15:58:00 GMT

摘要: SharpDevelop

强大的插件系统，通过Addin构建成一个功能齐全的.net开发IDE。核心是AddInTree。跟随这个项目开发许多有用的组件，比如功能文本编辑器（ICSharpCode.TextEditor），SharpZipLib等。

链接：http://www.icsharpcode.net/ 阅读全文

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一道面试题目引发的思考

暗香浮动 — Fri, 02 Nov 2007 01:59:00 GMT

摘要: 深入理解对象模型对我们理解面向对象的继承多态会大有裨益。
一直没找到C#这方面的知识，粗浅的看过一点侯捷C++对象模型，实际分析问题的时候发现还是没有深入理解。
无奈到园子里来请教大家。也希望高手前辈能够不吝赐教。如果有意写一些C#对象模型相关的文章我想对于新人来说可谓是莫大的帮助。期待，提前感谢。阅读全文

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类内部函数级别的strategy模式

暗香浮动 — Sun, 28 Oct 2007 09:54:00 GMT

摘要: 使用代理来模拟多态

今天在写一个把图片处理成HTML文本显示的时候，在两层的循环嵌套内逐个处理像素。
循环内部处理像素的时候有多种选择。(比如处理成彩色的还是处理成黑白的和其他多种算法。)
如果在这里进行判断的话需要上十万次的相同的与非判断。(彩色的都要判断为真，黑白的相反)
虽说影响不是太大，但是本着写程序的时候需要考虑去掉任何可能影响程序性能的非必须操作。

受设计模式的影响，考虑如果实现成类的话最可能选择的就是strategy模式了。
这里一个简单操作。所以考虑使用代理来模拟类的多态。阅读全文

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