A connectable object is one that supports outgoing interfaces. An outgoing interface allows the object to communicate with a client. For each outgoing interface, the connectable object exposes a connection point. Each outgoing interface is implemented by a client on an object called a sink.

Each connection point supports the [IConnectionPoint](/windows/desktop/api/ocidl/nn-ocidl-iconnectionpoint) interface. The connectable object exposes its connection points to the client through the [IConnectionPointContainer](/windows/desktop/api/ocidl/nn-ocidl-iconnectionpointcontainer) interface.

title: "Implementing a Property Page (ATL)"

helpviewer_keywords: ["property pages, implementing"]

ms.assetid: c30b67fe-ce08-4249-ae29-f3060fa8d61e

Now that your property page has been generated, you'll need to add a few controls to the dialog resource representing your page. Add an edit box, a static text control, and a check box and set their IDs as shown below:

These controls will be used to display the file name of the document and its read-only status.

title: "Fundamentals of ATL COM Objects"

helpviewer_keywords: ["COM, and ATL", "ATL, COM", "ATL COM objects", "COM objects, ATL"]

ms.assetid: 0f9c9d98-cc28-45da-89ac-dc94cee422fe

The following illustration depicts the relationship among the classes and interfaces that are used to define an ATL COM object.

title: "Identifying the Elements of the DHTML Control Project"

helpviewer_keywords: ["HTML controls, ATL support", "DHTML controls, ATL support"]

ms.assetid: b627547a-3768-4346-9900-4b7a21fb8e27

The following graphic illustrates the relationship between your DLL, the DHTML control, the Web browser, and the HTML resource.

The ATL Control Wizard generates a control with default code in both the HTML resource and the .cpp file. You can compile and run the control as generated by the wizard, and then view the control in either the Web browser or the ActiveX Control Test Container. The picture below shows the default ATL DHTML control with three buttons displayed in Test Container:

See [Creating an ATL DHTML Control](../atl/creating-an-atl-dhtml-control.md) to get started building a DHTML control. See [Testing Properties and Events with Test Container](../mfc/testing-properties-and-events-with-test-container.md) for information on how to access Test Container.

title: "ARM64 exception handling"

title: "Examples of Structure Alignment"

helpviewer_keywords: ["structure alignment", "examples [C++], structure alignment"]

ms.assetid: 03d137bf-5cc4-472e-9583-6498f2534199

}

}

title: "Creating Precompiled Header Files"

f1_keywords: ["pch"]

helpviewer_keywords: ["precompiled header files, creating", "PCH files, creating", "cl.exe compiler, precompiling code", ".pch files, creating"]

ms.assetid: e2cdb404-a517-4189-9771-c869c660cb1b

The figure uses three diagrammatic devices to show the flow of the build process. Named rectangles represent each file or macro; the three macros represent one or more files. Shaded areas represent each compile or link action. Arrows show which files and macros are combined during the compilation or linking process.

Beginning at the top of the diagram, both STABLEHDRS and BOUNDRY are NMAKE macros in which you list files not likely to need recompilation. These files are compiled by the command string

title: "Profile Guided Optimization in the Performance and Diagnostics Hub"

ms.assetid: dc3a1914-dbb6-4401-bc63-10665a8c8943

Open the Performance and Diagnostics Hub—on the menu bar, choose **Analyze**, **Performance and Diagnostics**. This opens a diagnostics session page that has the analysis tools that are available for your project type.

In **Available Tools**, select the **Profile Guided Optimization** check box. Choose the **Start** button to start the PGO plug-in.

The **Profile Guided Optimization** page describes the steps the plug-in uses to improve the performance of your app. Choose the **Start** button.

In the **Instrumentation** section, you use the **Training is initially enabled** option to choose whether to include the startup phase of your app as part of the training. If this option is not selected, training data is not recorded in a running instrumented app until you explicitly enable training.

Choose the **Instrument** button to build your app with a special set of compiler options. The compiler inserts probe instructions in the generated code. These instructions record profiling data during the training phase.

When the instrumented build of your app is complete, the app is started automatically.

If any errors or warnings occur during the build, correct them and then choose **Restart Build** to restart the instrumented build.

When your app is started, you can use the **Start Training** and **Pause Training** links in the **Training** section to control when profiling information is recorded. You can use the **Stop Application** and **Start Application** links to stop and restart the app.

During training, go through your user scenarios to capture the profiling information that the PGO plug-in needs to optimize the code. When you have completed the training, close your app or choose the **Stop Application** link. Choose the **Analyze** button to start the analysis step.

When the analysis is complete, the **Analysis** section shows a report of the profiling information that was captured during the user-scenario training phase. You can use this report to examine which functions your app called the most and spent the most time in. The PGO plug-in uses the information to determine which app functions to optimize for speed and which to optimize for size. The PGO plug-in configures build optimizations to create the smallest, fastest app for the user scenarios that you recorded during training.

If the training captured the expected profiling information, you can choose **Save Changes** to save the analyzed profile data in your project to optimize future builds. To discard the profile data and start the training over from the beginning, choose **Redo Training**.

The profile data file is saved in your project in a **PGO Training Data** folder. This data is used to control the compiler build optimization settings in your app.

After analysis, the PGO plug-in sets build options in your project to use the profile data to selectively optimize your app during compilation. You can continue to modify and build your app with the same profile data. When the app is built, the build output reports how many functions and instructions were optimized by using profile data.

If you make significant code changes during development, you may have to retrain your app to get the best optimizations. We recommend that you retrain your app when the build output reports that less than 80 percent of functions or instructions were optimized by using profile data.

title: Install C++ support in Visual Studio 2017

description: "Install Visual Studio support for Visual C++"

ms.custom: "mvc"

ms.topic: "tutorial"

ms.devlang: "C++"

ms.assetid: 45138d70-719d-42dc-90d7-1d0ca31a2f54

1. Find the installer file you downloaded and run it. It may be displayed in your browser, or you may find it in your Downloads folder. The installer needs Administrator privileges to run. You may see a **User Account Control** dialog asking you to give permission to let the installer make changes to your system; choose **Yes**. If you are having trouble, find the downloaded file in File Explorer, right-click on the installer icon, and choose **Run as Administrator** from the context menu.

1. The installer presents you with a list of workloads, which are groups of related options for specific development areas. Support for C++ is now part of optional workloads that aren't installed by default.

For C++, select the **Desktop development with C++** workload and then choose **Install**.