runtime | 易学教程

Objective-C-Runtime Bug When Naming a Superclass “Message”

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问题 I have the following class hierachy: @interface Message : NSObject {} @end @implementation Message - (void) dealloc { // I won't be called [super dealloc]; } @end @interface FooMessage : Message {} @end @implementation FooMessage - (void) dealloc { // should call Message - dealloc [super dealloc]; } @end And the following unit test: - (void) test { FooMessage* msg = [[FooMessage alloc] init]; [msg release]; } The test will always fail with EXC_BAD_INSTRUCTION. FooMessage calls it's super

深入了解Dynamic & DLR（一）

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本文主要谈谈个人对DLR的认识和学习，希望能和大家一起探讨下。主要内容： DLR在面向服务设计的必要性 dynamic类型 DLR ScriptRuntime DynamicObject & ExpandoObject 1.DLR在面向服务设计中的必要性题外前因话：商业业务环境的变更总是伴随着技术的变革。近来面向服务编程SOA的兴起是一种必然，涉及以下几个因素：其一商业经营需要及时快速的调整；其二在快速调整的同时，无需额外的开销，无需重构代码，重新发布平台；其三商业平台的扩展性和稳定性；其四商业平台维护费用； SOA在业务平台整体上进行布局整合，发布服务契约，数据契约等等，那么涉及细颗粒度的操作，比如说商场需要实时对销货策略进行变更。1.客户类别不同打折销售，2.节假日不同打折，3.不同的商品类别折扣不同，4.促销商品折扣，5.销售额满多少，折扣多少等等，我们需要以后对销售策略进行实时维护，能新增，删除，修改。在当前我们可能通过App.config文件设置不同参数值来满足我们的业务需求，或者通过dll反射的方式来选择不同销售策略。但这些能灵活配置的有限，无法满足日益增长复杂业务逻辑的变化。对此我们需要这些业务需求能够“动态加载，动态注入”，最好是脚本语言，不需要进行第二次编译，现有的Framework能够自动解析执行。 C#仍是一种静态的类型化语言，无法完美支持动态编程

How to programmatically construct components at runtime using C++ Builder?

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问题 Very basic C++ Builder question. I want to create a TButton at runtime. I would have thought that the following code would do it, but I see no button on the form: __fastcall TForm2::TForm2(TComponent* Owner): TForm(Owner) { TButton* b = new TButton(this); b->Height = 100; b->Width = 100; b->Left = 0; b->Top = 0; b->Caption = "Testing"; b->Visible = true; b->Enabled = true; } Thanks for any help! 回答1: You need to set the button's Parent (the surface it displays on): b->Parent = this; 来源： https

How to check existence of a program in the path

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问题 I'm writing a program in scala which call: Runtime.getRuntime().exec( "svn ..." ) I want to check if "svn" is available from the commandline (ie. it is reachable in the PATH). How can I do this ? PS: My program is designed to be run on windows 回答1: I'm no scala programmer, but what I would do in any language, is to execute something like ' svn help ' just to check the return code (0 or 1) of the exec method... if it fails the svn is not in the path :P Runtime rt = Runtime.getRuntime();

Running PHP from Java

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问题 I am trying to run the following from java file. I am trying to display the php version and later will change to run php files. Process p = Runtime.getRuntime().exec("cmd /C PHP/php.exe -v"); BufferedReader in = new BufferedReader(new InputStreamReader( p.getInputStream())); String line = null; while ((line = in.readLine()) != null) { System.out.println(line); } When I run the program, there is no error. but console is not displaying anything :( Thank you. 回答1: You have to wait for the

How can we handle enable/disable background audio abilities at runtime on iOS devices?

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问题 I know how to set up my iOS application to make it playing audio in background (= when another application is used on the iOS device) using the plist. Some applications like: - BLOOM - some radio players provides a basic UISwitch to enable or disable this behavior. Any ideas about how to do that ? 回答1: Have an iVar of type UIBackgroundTaskIdentifier in the main class that handles audio playing code, initialize this with beginBackgroundTaskWithExpirationHandler.... method before starting the

How can we handle enable/disable background audio abilities at runtime on iOS devices?

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Executing external program in java and passing commands

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问题 I have this chess engine Rybka.exe, that i have to execute in java Here is an example how you run Rybka: Once you clicked on it, console opens and waits for input. So then you enter "uci" and you press enter and you wait for it to load (approx. 1 sec) and then you have to enter a few more lines as options and stuff. The problem is that I don't know how to pass those commands from java to Rybka. The fact is that those commands need to be entered one at a time, because you have to wait for some

Change language on runtime in Android

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问题 I have to change the language on runtime in Android (yes, I know that this is not a good behaviour, but this is a requirement...). So I have a basic class, from which every activity extends. This class has the following function: public static void changeLanguage(Context context) { Resources res = context.getResources(); /* * Change locale settings in the app. */ DisplayMetrics dm = res.getDisplayMetrics(); /* * Store and load data in this preferences */ android.content.res.Configuration conf

Convert string to code at run time c++

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问题 I am generating If Else Expressions of the following format If(X > 10) Then Fly = True Else Fly = False If(X > 9) Then Fly = True Else Fly = False If(X > 8) Then Fly = True Else Fly = False If(X > 7) Then Fly = True Else Fly = False If(X > 6) Then Fly = True Else Fly = False I was Wondering Can i execute this expressions at run time? I don't know if my question is clear. I'll add an example String = ""; for(int i = 0; i < n; i++) { string ="if(x > 10){Fly = true;} else {Fly = False;}";