If your app utilizes WebView to display web content, you might want to consider optimizing click behavior for the following reasons:
-
WebViewdoesn't support tabbed browsing . Clicking a link opens the content in the default web browser.
-
WebViewdoesn't support custom URL schemes which could be returned in ads if the click destination is to a separate app. For example, a Google Play click-through URL might usemarket://.
- Google Sign-in and Facebook Sign-in aren't supported in
WebView.
This guide provides recommended steps to optimize the click behavior in mobile web views while preserving the web view content.
Предварительные требования
- Выполните все шаги руководства по настройке веб-представления .
Выполнение
Follow these steps to optimize the click behavior in your WebView instance:
Override
shouldOverrideUrlLoading()on theWebViewClient. This method is called when a URL is about to be loaded in the currentWebView.Determine whether to override the behavior of the click URL.
The code example checks if the current domain is different than the target domain. This is just one approach as the criteria you use could vary.
Решите, открывать ли URL-адрес во внешнем браузере, в Android Custom Tabs или в существующем веб-интерфейсе. В этом руководстве показано, как открывать URL-адреса, переходя с сайта на другой, с помощью Android Custom Tabs.
Пример кода
First add the androidx.browser dependency to your module-level build.gradle file, typically app/build.gradle . This is required for Custom Tabs:
dependencies {
implementation 'androidx.browser:browser:1.5.0'
}
The following code snippet shows how to implement shouldOverrideUrlLoading() :
Java
public class MainActivity extends AppCompatActivity {
private WebView webView;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// ... Register the WebView.
webView = new WebView(this);
WebSettings webSettings = webView.getSettings();
webSettings.setJavaScriptEnabled(true);
webView.setWebViewClient(
new WebViewClient() {
// 1. Implement the web view click handler.
@Override
public boolean shouldOverrideUrlLoading(
WebView view,
WebResourceRequest request) {
// 2. Determine whether to override the behavior of the URL.
// If the target URL has no host and no scheme, return early.
if (request.getUrl().getHost() == null && request.getUrl().getScheme() == null) {
return false;
}
// Handle custom URL schemes such as market:// by attempting to
// launch the corresponding application in a new intent.
if (!request.getUrl().getScheme().equals("http")
&& !request.getUrl().getScheme().equals("https")) {
Intent intent = new Intent(Intent.ACTION_VIEW, request.getUrl());
// If the URL cannot be opened, return early.
try {
MainActivity.this.startActivity(intent);
} catch (ActivityNotFoundException exception) {
Log.d("TAG", "Failed to load URL with scheme:" + request.getUrl().getScheme());
}
return true;
}
String currentDomain;
// If the current URL's host cannot be found, return early.
try {
currentDomain = new URI(view.getUrl()).toURL().getHost();
} catch (URISyntaxException | MalformedURLException exception) {
// Malformed URL.
return false;
}
String targetDomain = request.getUrl().getHost();
// If the current domain equals the target domain, the
// assumption is the user is not navigating away from
// the site. Reload the URL within the existing web view.
if (currentDomain.equals(targetDomain)) {
return false;
}
// 3. User is navigating away from the site, open the URL in
// Custom Tabs to preserve the state of the web view.
CustomTabsIntent intent = new CustomTabsIntent.Builder().build();
intent.launchUrl(MainActivity.this, request.getUrl());
return true;
}
});
}
}
Котлин
class MainActivity : AppCompatActivity() {
private lateinit var webView: WebView
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
// ... Register the WebView.
webView.webViewClient = object : WebViewClient() {
// 1. Implement the web view click handler.
override fun shouldOverrideUrlLoading(
view: WebView?,
request: WebResourceRequest?
): Boolean {
// 2. Determine whether to override the behavior of the URL.
// If the target URL has no host and no scheme, return early.
if (request?.url?.host == null && request.url.scheme == null) {
return false
}
val currentDomain = URI(view?.url).toURL().host
// Handle custom URL schemes such as market:// by attempting to
// launch the corresponding application in a new intent.
if (!request.url.scheme.equals("http") &&
!request.url.scheme.equals("https")) {
val intent = Intent(Intent.ACTION_VIEW, request.url)
// If the URL cannot be opened, return early.
try {
this@MainActivity.startActivity(intent)
} catch (exception: ActivityNotFoundException) {
Log.d("TAG", "Failed to load URL with scheme: ${request.url.scheme}")
}
return true
}
val targetDomain = request.url.host
// If the current domain equals the target domain, the
// assumption is the user is not navigating away from
// the site. Reload the URL within the existing web view.
if (currentDomain.equals(targetDomain)) {
return false
}
// 3. User is navigating away from the site, open the URL in
// Custom Tabs to preserve the state of the web view.
val customTabsIntent = CustomTabsIntent.Builder().build()
customTabsIntent.launchUrl(this@MainActivity, request.url)
return true
}
}
}
}
Проверьте навигацию по страницам.
Чтобы проверить изменения в навигации страницы, загрузите
https://google.github.io/webview-ads/test/#click-behavior-tests
into your web view. Click each of the different link types to see how they behave in your app.
Вот что следует проверить:
- Каждая ссылка открывает нужный URL-адрес.
- When returning to the app, the test page's counter doesn't reset to zero to validate the page state was preserved.