moc | 易学教程

神龙架构没那么难理解—图解世界领先的阿里云神龙架构（二）神龙出世

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【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 3 神龙出世 3.1 继续说我们的搬砖问题第2章中指出只要采用虚拟化和弹性计算，就代表100个劳动力必须选择1个管理人员，实际上只能有99个劳动力进行搬砖。而神龙想做到的目标就是既然100个工人搬砖，就要全部搬砖，但同时也需要有手段来管理和控制我家和邻居家不同时间搬砖的工人数。以上图为例就是让黄色的那个被抽出来负责管理工作的工人回去仍然搬砖去。包工头看着目前的情况想，如果要维持两家搬砖的工人弹性灵活，就需要100个工人抽1个工人做管理工作，那如果1000个工人就需要损失10个，10000个工人就需要损失100个。工程量越大则损失的劳动力就越多，当业务得到大规划发展时这个损耗的问题如果能够解决就可以大幅度的提升搬砖的效率。阿里云在神龙架构问世前的虚拟化损耗其实比搬砖的例子更大，平均虚拟化损耗为10%左右，代表100个工人，只有90个在搬砖，剩下的10个在做搬砖管理工作。 3.2 神龙1.0的核心理念结合实际情况包工头决定让原来被抽出来做管理工作的工人甲仍然回去搬他的砖去，因为他的力气大的特点意味着他本来就适合搬砖而不适合管理工作。而工人队伍的管理工作采用项目经理制，即引入专业管理人员来负责工人队伍的管理，使工人只负责搬砖，当然引入专业管理人员后，成本肯定是上升的，但是搬砖的劳动力就没有损耗了

Why is my MOC_DIR ignored when generating Visual Studio projects with qmake

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问题 I'm generating Visual Studio 2013 projects with Qt 5.3 qmake . In my .pro file, I've got the following line: MOC_DIR = $$BUILD_DIR/<DEBUG OR RELEASE>/moc If I message($$MOC_DIR) , the path is correctly formed. However, when I build in VS, the moc_<CLASS>.cpp files are not generated in that location, but instead end up in the same directory as the .pro . I get the following warning during compilation: Two or more files with the name of moc_<CLASS>.cpp will produce outputs to the same location

QT .pro file: How to change default include path for MAC frameworks

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问题 My .pro file looks like this: QT += core gui widgets SOURCES += a.cpp HEADERS += a.h FORMS += a.ui #Locally compiled Qt framework. Qt/out/{QtCore.framework,QtNetwork.framework..} QMAKE_LFLAGS += -L./Qt/lib/ QMAKE_CXXFLAGS += -F./Qt/lib/ macx { QMAKE_MAC_SDK = macosx10.9 LIBS += -framework QtCore -framework QtNetwork -framework QtGui -framework QtWidgets } I want to use frameworks compiled locally, but QT5.5 automatically includes framework from QT5.5.0 install directory ... I see a.cpp

How do I display an MOC user's online status on a web page without Active-X?

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问题 Is it possible to display a user's online status without Active-X? In my googling I've found a number of articles about displaying MOC online status on Sharepoint using the IMNRC() function in the OWS.js file but this seems pretty old-skool with all of the Active-X object instantiation and as a result will only work in Internet Explorer. Is there a simple method of getting an online status using some kind of back-end API call to the communication server by passing their email address? cheers

Compiling QObject-derived class on the command line on Linux

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问题 I am new to Qt. I am trying to compile a small code snippet shown below: #include<QtCore/QtCore> #include<QtCore/QObject> class Test:public QObject { Q_OBJECT public: Test(){qDebug()<<"CTOR";} }; int main() { Test t; return 0; } I am trying to run it through command line using the following command: g++ -o signalTest.exe -l QtCore signalTest.cpp However I am getting the following error: undefined reference to vtable for Test I think I need to include the library for QObject , but I am not

QMake moc files confused by namespaces

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问题 I have a file that looks like: #ifndef ENGINE_PLATFORM_AREAEDITOR_H #define ENGINE_PLATFORM_AREAEDITOR_H #include <QWidget> #include "../Widgets/QtSfmlWidget.h" namespace Engine { namespace World { class Area; } } //This tell's Qt's qmake to ignore the code between MOC_SKIP_BEGIN and MOC_SKIP_END // MOC_SKIP_BEGIN #include "Engine/World/Area.h" // MOC_SKIP_END namespace Ui { class AreaEditor; } class AreaEditor : public QWidget { Q_OBJECT public: Engine::World::Area area; public: explicit

Qt 5 cmake fails with undefined reference to vtable on hello world with inc & src as subdirs

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问题 Update 2 After messing around a bit (and some editing of the generated Makefiles), it looks like what is happening is that moc is not properly processing MainWindow.h (included by main.cpp and MainWindow.cpp unless it is in the same folder as the source files which included it. Moc runs on MainWindow.cpp , doesn't process the include and thus doesn't see the Q_OBJECT macro so proceeds to produce an empty output file. I'm not sure whether moc usually processes includes or if it just scans the

Qt/Qml and method overloads

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问题 Just came across a weird behavior of Qt framework while invoking overloaded C++ methods from within Qml and trying to understand the reason behind it. Let's say I have a QList<QVariant> -like class with the following methods: ... Q_SLOT void append(const QVariant &item); Q_SLOT void append(const QVariantList &items); Q_SLOT void insert(int index, const QVariant &item); Q_SLOT void insert(int index, const QVariantList &items); ... Qml: onclicked: { var itemCount = myListObject.size();

Qt Moc'ing multiple files in parallel under msbuild

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问题 Using the Qt Visual studio plugin it seems to take care of most of almost everything in a seemless manner. Unfortunately it does the moc'ing using a CustomBuild step in msbuild. This results in a serial moc'ing, one after another. Is there a way to convince msbuild to do them in parallel - I'm tired of 7 cores sitting on their laurels like me. I've seen msbuild's BuildInParallel, but I'm not sure how to make that apply here. msbuild snippet: <Project> ... <ItemGroup> <CustomBuild Include="a

Get a number of resources asynchronously and “asynchronously” save them to a database. Which good pattern to use? (AFNetworking, Core Data)

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I need to populate my map with annotations. Each annotation has corresponding Place resource that is being fetched from remote server. Each Place has associated Category - it is fetched from the server too as a separate resource. Let's assume that to populate a given region I need to fetch 100 places, each belonging to the one of 20 categories (actually there are much more of them). I use AFNetworking to fetch the both of resources. I try to cache both places and categories for offline use, so before the annotations are displayed on map, I write fetched resources to the Core Data tables. Each