Target Devices and Processes

为了使用跟踪文档对某些内容进行配置，需要对其进行目标定位。也就是说，您需要告诉仪器您想要什么样的配置文件，以及您想要对它进行什么样的配置，例如在设备上或模拟器中。In order to profile something with a trace document, you need to target it. That is, you need to tell Instruments what you want to profile and where you want to profile it, such as on a device or in a simulator.

创建新跟踪文档时，工具会显示分析模板选择对话框。该对话框顶部包括一个目标设备列表和一个目标进程列表（图7-1），它允许你指定目标时，当你选择一个模板。这些列表包括配置或连接到Mac的任何设备，包括模拟器，以及用于对这些设备进行分析的任何流程。最近有针对性的进程、应用程序扩展、活动进程和系统进程也被列出。When you create a new trace document, Instruments displays the profiling template selection dialog. The top of this dialog includes a target device list and a target process list (Figure 7-1), which allow you to specify the desired target when when you choose a template. These lists include any devices that are configured or connected to your Mac, including simulators, as well as any processes available for profiling on those devices. Recently targeted processes, app extensions, active processes, and system processes are also listed.

Figure 7-1剖析模板选择对话框中的目标设备和进程列表Target device and process lists in the profiling template selection dialog

目标列表中的每一道文档工具栏也可用（见图7-2），允许你改变目标在任何时间在一个跟踪文件工作。Target lists are also available in the toolbar of every trace document (see Figure 7-2), allowing you to change the target at any time while working in a trace document.

Figure 7-2装置和过程跟踪中文档工具栏列表Target device and process lists in the trace document toolbar

1. 单击目标设备列表或目标进程列表，并选择所需的设备和进程。Click the target device list or target process list, and select the desired device and process.

   

   有些工具允许您针对所有进程。如果您想这样做，请选择目标进程列表中的所有进程。Some instruments allow you to target all processes. If you want to do this, select All Processes in the target process list.

   

   如果未列出所需的流程，请在目标流程列表中选择“目标”。这将显示一个对话框，允许您浏览任何进程。您还可以通过这个对话框配置进程的环境变量。If the desired process isn’t listed, select Choose Target in the target process list. This displays a dialog that allows you to browse for any process. You can also configure environment variables for a process through this dialog.

   

针对iOS设备Target an iOS Device

若要针对iOS设备，请将设备连接到您的开发Mac。一旦连接，该设备会出现在目标设备列表，如图7-3所示。To target an iOS device, connect the device to your development Mac. Once connected, the device appears in the target device list, as shown in Figure 7-3.

Figure 7-3Targeting an iOS device in Instruments

以无线方式锁定iOS设备Target an iOS Device Wirelessly

仪器还允许您从iOS设备无线采集数据。在测试以下内容时，无线剖析特别有用：Instruments also allows you to collect data from an iOS device wirelessly. Wireless profiling is especially useful when testing the following:

• 加速度计。将设备移动到各个方向而不被栓住。Accelerometers. Move the device in all directions without its being tethered.

• 配件.将USB附件插入空闲槽中并进行测试。Accessories. Plug your USB accessory into the free slot and test it.

1. 确保你的iOS设备通过USB或闪电电缆连接到你的开发Mac上。Make sure your iOS device is connected to your development Mac by a USB or Lightning cable.

   

2. 按下选项键，然后单击目标设备列表。Press the Option key, and click the target device list.

3. 选择您的移动设备以启用它的无线分析。Select your mobile device to enable wireless profiling for it.

   

4. 再次单击目标设备列表以打开它，选择设备的无线版本，然后选择一个进程。Click the target device list again to open it, select the wireless version of your device, and select a process.

   

5. Disconnect the device from the USB or Lightning cable.

   You should now be able to profile the process wirelessly on your device.

Target an Apple Watch

Before targeting an Apple Watch with Instruments, you must first prepare the Apple Watch for profiling.

1. Ensure that your Apple Watch is paired with your development iPhone.

2. Quit Instruments.

3. Launch Xcode.

4. Connect the iPhone that’s paired with your Apple Watch to your development Mac by a USB or Lightning cable.

   

5. Choose Window > Devices (or press Shift-Command-2) to open the Devices window in Xcode.

6. Wait for the iPhone to appear in the Devices list.

7. Wait for the Apple Watch to appear as a paired device for the iPhone.

8. Wait for Xcode to indicate that the Apple Watch has been prepared. This process may take several minutes.

   

9. Disconnect the iPhone from the USB or Lightning cable.

10. Connect the iPhone to the USB or Lightning cable again.

Once your Apple Watch has been prepared for profiling, relaunch Instruments, and the Apple Watch should appear in the target device list, as shown in Figure 7-4.

Figure 7-4Targeting an Apple Watch in Instruments

Other Ways to Target

In this chapter, you learned how to specify a target app and device in Instruments. However, you can also target an app externally, without actually entering the Instruments app directly. Visit the following sections to learn more:

• Profile from the Dock

• Profile from Xcode

• Profile from the Command Line

Target Devices and Processes