WebView2

简介

以下将解释如何将 Playwright 与 Microsoft Edge WebView2 结合使用。WebView2 是一个 WinForms 控件，它将在底层使用 Microsoft Edge 来渲染 Web 内容。它是 Microsoft Edge 浏览器的一部分，可在 Windows 10 和 Windows 11 上使用。Playwright 可用于自动化 WebView2 应用程序，并可用于测试 WebView2 中的 Web 内容。为了连接到 WebView2，Playwright 使用 BrowserType.connectOverCDP()，它通过 Chrome DevTools 协议 (CDP) 连接到 WebView2。

概述

可以指示 WebView2 控件监听传入的 CDP 连接，方法是设置 WEBVIEW2_ADDITIONAL_BROWSER_ARGUMENTS 环境变量为 --remote-debugging-port=9222，或者使用 --remote-debugging-port=9222 参数调用 EnsureCoreWebView2Async。这将启动启用 Chrome DevTools 协议的 WebView2 进程，从而允许 Playwright 进行自动化。9222 在这里只是一个示例端口，也可以使用任何其他未使用的端口。

await this.webView.EnsureCoreWebView2Async(await CoreWebView2Environment.CreateAsync(null, null, new CoreWebView2EnvironmentOptions()
{
  AdditionalBrowserArguments = "--remote-debugging-port=9222",
})).ConfigureAwait(false);

一旦您的带有 WebView2 控件的应用程序正在运行，您就可以通过 Playwright 连接到它

Browser browser = playwright.chromium().connectOverCDP("https://127.0.0.1:9222");
BrowserContext context = browser.contexts().get(0);
Page page = context.pages().get(0);

为了确保 WebView2 控件已准备就绪，您可以等待 CoreWebView2InitializationCompleted 事件

this.webView.CoreWebView2InitializationCompleted += (_, e) =>
{
    if (e.IsSuccess)
    {
        Console.WriteLine("WebView2 initialized");
    }
};

编写和运行测试

默认情况下，WebView2 控件将对所有实例使用相同的用户数据目录。这意味着，如果您并行运行多个测试，它们将相互干扰。为了避免这种情况，您应该为每个测试将 WEBVIEW2_USER_DATA_FOLDER 环境变量（或使用 WebView2.EnsureCoreWebView2Async 方法）设置为不同的文件夹。这将确保每个测试都在其自己的用户数据目录中运行。

使用以下方法，Playwright 将把您的 WebView2 应用程序作为子进程运行，为其分配唯一的用户数据目录，并为您的测试提供 Page 实例

WebView2Process.java

package com.example;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;

public class WebView2Process {
  public int cdpPort;
  private Path _dataDir;
  private Process _process;
  private Path _executablePath = Path.of("../webview2-app/bin/Debug/net8.0-windows/webview2.exe");

  public WebView2Process() throws IOException {
    cdpPort = nextFreePort();
    _dataDir = Files.createTempDirectory("pw-java-webview2-tests-");

    if (!Files.exists(_executablePath)) {
      throw new RuntimeException("Executable not found: " + _executablePath);
    }
    ProcessBuilder pb = new ProcessBuilder().command(_executablePath.toAbsolutePath().toString());
    Map<String, String> envMap = pb.environment();
    envMap.put("WEBVIEW2_ADDITIONAL_BROWSER_ARGUMENTS", "--remote-debugging-port=" + cdpPort);
    envMap.put("WEBVIEW2_USER_DATA_FOLDER", _dataDir.toString());
    _process = pb.start();
    // wait until "WebView2 initialized" got printed
    BufferedReader reader = new BufferedReader(new InputStreamReader(_process.getInputStream()));
    while (true) {
      String line = reader.readLine();
      if (line == null) {
        throw new RuntimeException("WebView2 process exited");
      }
      if (line.contains("WebView2 initialized")) {
        break;
      }
    }
  }

  private static final AtomicInteger nextUnusedPort = new AtomicInteger(9000);

  private static boolean available(int port) {
    try (ServerSocket ignored = new ServerSocket(port)) {
      return true;
    } catch (IOException ignored) {
      return false;
    }
  }

  static int nextFreePort() {
    for (int i = 0; i < 100; i++) {
      int port = nextUnusedPort.getAndIncrement();
      if (available(port)) {
        return port;
      }
    }
    throw new RuntimeException("Cannot find free port: " + nextUnusedPort.get());
  }

  public void dispose() {
    _process.destroy();
    try {
      _process.waitFor();
    } catch (InterruptedException e) {
      throw new RuntimeException(e);
    }
  }
}

TestExample.java

package com.example;

import com.microsoft.playwright.Browser;
import com.microsoft.playwright.BrowserContext;
import com.microsoft.playwright.Locator;
import com.microsoft.playwright.Page;
import com.microsoft.playwright.Playwright;
import org.junit.jupiter.api.*;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static com.microsoft.playwright.assertions.PlaywrightAssertions.assertThat;

import java.io.IOException;

public class TestExample {
  // Shared between all tests in this class.
  static WebView2Process webview2Process;
  static Playwright playwright;
  static Browser browser;
  static BrowserContext context;
  static Page page;

  @BeforeAll
  static void launchBrowser() throws IOException {
    playwright = Playwright.create();
    webview2Process = new WebView2Process();
    browser = playwright.chromium().connectOverCDP("http://127.0.0.1:" + webview2Process.cdpPort);
    context = browser.contexts().get(0);
    page = context.pages().get(0);
  }

  @AfterAll
  static void closeBrowser() {
    webview2Process.dispose();
  }

  @Test
  public void shouldClickButton() {
    page.navigate("https://playwright.net.cn");
    Locator gettingStarted = page.getByText("Get started");
    assertThat(gettingStarted).isVisible();
  }
}

调试

在您的 webview2 控件中，您只需右键单击即可打开上下文菜单，然后选择“检查”以打开 DevTools，或按 F12 键。您还可以使用 WebView2.CoreWebView2.OpenDevToolsWindow 方法以编程方式打开 DevTools。

有关调试测试的信息，请参阅 Playwright 调试指南。