selenium chrome浏览器启动设置，加载浏览器相关插件设置方法。

Capabilities are options that you can use to customize and configure a ChromeDriver session. This page documents all ChromeDriver supported capabilities and how to use them.

There are two ways to specify capabilities. 

1. The first is to use the ​​ChromeOptions​​ class.  
2. If your client library does not have a ​​ChromeOptions​​​ class (like the selenium ruby client), you can specify the capabilities directly as part of the ​​DesiredCapabilities​​.

Using the ChromeOptions class

You can create an instance of ​​ChromeOptions​​​, which has convenient methods for setting ChromeDriver-specific capabilities. You can pass the ​​ChromeOptions​​ object directly into the ChromeDriver constructor:

ChromeOptions options = new ChromeOptions();
options.addExtensions(new File("/path/to/extension.crx"));
ChromeDriver driver = new ChromeDriver(options);

Alternatively, you can add the options to an already existing ​​DesiredCapabilities​​ object, which is useful when need to specify other WebDriver capabilities not specific to ChromeDriver.

DesiredCapabilities capabilities = DesiredCapabilities.chrome();

// Add the WebDriver proxy capability.
Proxy proxy = new Proxy();
proxy.setHttpProxy("myhttpproxy:3337");
capabilities.setCapability("proxy", proxy);

// Add ChromeDriver-specific capabilities through ChromeOptions.
ChromeOptions options = new ChromeOptions();
options.addExtensions(new File("/path/to/extension.crx"));
capabilities.setCapability(ChromeOptions.CAPABILITY, options);
ChromeDriver driver = new ChromeDriver(capabilities);

Using DesiredCapabilities directly

The ​​ChromeOptions​​​ class uses ​​DesiredCapabilities​​​ underneath. To use ​​DesiredCapabilities​​ directly, you need to know the name of the capability and the type of value it takes. See the full list further below.

Java

Map<String, Object> chromeOptions = new Map<String, Object>();
chromeOptions.put("binary", "/usr/lib/chromium-browser/chromium-browser");
DesiredCapabilities capabilities = DesiredCapabilities.chrome();
capabilities.setCapability(ChromeOptions.CAPABILITY, chromeOptions);
WebDriver driver = new ChromeDriver(capabilities);

Ruby

caps = Selenium::WebDriver::Remote::Capabilities.chrome("chromeOptions" => {"args" => [ "--disable-web-security" ]})
driver = Selenium::WebDriver.for :remote, url: 'http://localhost:4444/wd/hub' desired_capabilities: caps

Common use cases

Use custom profile (also called user data directory)

By default, ChromeDriver will create a new temporary profile for each session. At times you may want to set special preferences or just use a custom profile altogether. If the former, you can use the 'chrome.prefs' capability (described later below) to specify preferences that will be applied after Chrome starts. If the latter, you can use the ​​user-data-dir​​ Chrome command-line switch to tell Chrome which profile to use:

ChromeOptions options = new ChromeOptions();
options.addArguments("user-data-dir=/path/to/your/custom/profile");

You can create your own custom profile by just running Chrome (on the command-line or through ChromeDriver) with the ​​user-data-dir​​ switch set to some new directory. If the path doesn't exist, Chrome will create a new profile in the specified location. You can then modify the profile settings as desired, and ChromeDriver can use the profile in the future. Open chrome://version in the browser to see what profile Chrome is using.

Start Chrome maximized

ChromeOptions options = new ChromeOptions();
options.addArguments("start-maximized");

Using a Chrome executable in a non-standard location

ChromeOptions options = new ChromeOptions();
options.setBinary("/path/to/other/chrome/binary");

Set a Chrome preference

ChromeOptions options = new ChromeOptions();
Map<String, Object> prefs = new HashMap<String, Object>();
prefs.put("profile.default_content_settings.popups", 0);
options.setExperimentalOption("prefs", prefs);

List of recognized capabilities

This is a list of all the WebDriver-standard capabilities that ChromeDriver supports:

​​Proxy​​ object

See ​​http://code.google.com/p/selenium/wiki/DesiredCapabilities#Proxy_JSON_Object​​ 

​​loggingPrefs​​ object

See ​​https://code.google.com/p/selenium/wiki/DesiredCapabilities#JSON_object ​​

​​chromeOptions​​ object

This is a list of all the Chrome-specific desired capabilities, which all are under the ​​chromeOptions​​ dictionary. 

If possible, use the ​​ChromeOptions​​ class instead of specifying these directly.

​​perfLoggingPrefs​​ object

The perfLoggingPrefs dictionary has the following format (all keys are optional):

 Name

Type

Default 

Description 

​​args ​​

list of strings 

List of command-line arguments to use when starting Chrome. Arguments with an associated value should be separated by a '=' sign (e.g., ['start-maximized', 'user-data-dir=/tmp/temp_profile']). See ​​here​​ for a list of Chrome arguments.

​​binary​​

string 

Path to the Chrome executable to use (on Mac OS X, this should be the actual binary, not just the app. e.g., '/Applications/Google Chrome.app/Contents/MacOS/Google Chrome')

​​extensions​​

list of strings 

A list of Chrome extensions to install on startup. Each item in the list should be a base-64 encoded packed Chrome extension (.crx)

​​localState​​

dictionary

A dictionary with each entry consisting of the name of the preference and its value. These preferences are applied to the Local State file in the user data folder.

​​prefs​​

dictionary

A dictionary with each entry consisting of the name of the preference and its value. These preferences are only applied to the user profile in use. See the 'Preferences' file in Chrome's user data directory for examples.

​​detach​​

boolean

false 

If false, Chrome will be quit when ChromeDriver is killed, regardless of whether the session is quit. If true, Chrome will only be quit if the session is quit (or closed). Note, if true, and the session is not quit, ChromeDriver cannot clean up the temporary user data directory that the running Chrome instance is using.

​​debuggerAddress​​

string 

An address of a Chrome debugger server to connect to, in the form of <hostname/ip:port>, e.g. '127.0.0.1:38947'

​​excludeSwitches​​

list of strings 

List of Chrome command line switches to exclude that ChromeDriver by default passes when starting Chrome.  Do not prefix switches with --.

​​minidumpPath ​​

string 

Directory to store Chrome minidumps . (Supported only on Linux.)

​​mobileEmulation​​

dictionary

A dictionary with either a value for “deviceName,” or values for “deviceMetrics” and “userAgent.” Refer to Mobile Emulation for more information.

​​perfLoggingPrefs​​

dictionary

 An optional dictionary that specifies performance logging preferences. See below for more information.

 windowTypes

 list of strings

A list of window types that will appear in the list of window handles. For access to <webview> elements, include "webview" in this list.