Android怎么使用高版本的Webview

        Android怎么使用高版本的Webview

前言

   最近客户提出一个问题，就是由于Android的内置版本WebView版本过低，用户希望能使用高版本的WebView。这个问题有两种解决办法，第一就是系统将内置WebView版本提高，第二就是客户需要使用什么版本的WebView，自行下载然后固件将客户下载的版本作为默认版本。下面分别介绍在Android 5.1和7.1的版本上面的实施步骤。

Android 5.xx版本实施

   该版本使用客户下载的谷歌WebView作为默认的WebView版本，比较简单，原理就是加载默认WebView的时候判断当前是否有谷歌的WebView，如果有就是用谷歌的。

diff --git a/frameworks/base/core/java/android/webkit/WebViewFactory.java b/frameworks/base/core/java/android/webkit/WebViewFactory.java
old mode 100644
new mode 100755
index 474ef422d0..6f652ae061
--- a/frameworks/base/core/java/android/webkit/WebViewFactory.java
+++ b/frameworks/base/core/java/android/webkit/WebViewFactory.java
@@ -69,6 +69,8 @@ public final class WebViewFactory {
 
 
     private static final boolean DEBUG = false;
 
+       private static final String GOOGLE_WEBVIEW_NAME = "com.google.android.webview";
+
     // Cache the factory both for efficiency, and ensure any one process gets all webviews from the
     // same provider.
     private static WebViewFactoryProvider sProviderInstance;
@@ -77,10 +79,31 @@ public final class WebViewFactory {
     private static PackageInfo sPackageInfo;
 
     public static String getWebViewPackageName() {
+               if(isGoogleWebViewExist()){
+                       return GOOGLE_WEBVIEW_NAME;
+               }
         return AppGlobals.getInitialApplication().getString(
                 com.android.internal.R.string.config_webViewPackageName);
     }
 
+       public static boolean isGoogleWebViewExist(){
+               Application initialApplication = AppGlobals.getInitialApplication();
+               PackageInfo packageInfo;
+               try {
+                       packageInfo = initialApplication.getPackageManager().getPackageInfo(GOOGLE_WEBVIEW_NAME, 0);
+               }catch(Exception e){
+                       packageInfo = null;
+                       Log.e(LOGTAG, "error instantiating provider", e);
+               }
+
+               if(packageInfo == null){
+                       return false;
+               }else{
+                       return true;
+               }
+
+       }
+

Android 7.xx版本实施

   该版本使用客户下载的谷歌WebView作为默认的WebView版本，修改逻辑要比5.xx版本复杂，但是原理是一样的就是加载默认WebView的时候判断当前是否有谷歌的WebView，如果有就是用谷歌的，反之就是用系统默认的版本。

diff --git a/frameworks/base/core/res/res/xml/config_webview_packages.xml b/frameworks/base/core/res/res/xml/config_webview_packages.xml
old mode 100644
new mode 100755
index f062b59a00..5d51f62a0f
--- a/frameworks/base/core/res/res/xml/config_webview_packages.xml
+++ b/frameworks/base/core/res/res/xml/config_webview_packages.xml
@@ -16,6 +16,8 @@
 
 <webviewproviders>
     <!-- The default WebView implementation -->
+    <webviewprovider description="Google WebView" packageName="com.google.android.webview">
+    </webviewprovider>
     <webviewprovider description="Android WebView" packageName="com.android.webview" availableByDefault="true">
     </webviewprovider>
 </webviewproviders>
diff --git a/frameworks/base/services/core/java/com/android/server/webkit/WebViewUpdateService.java b/frameworks/base/services/core/java/com/android/server/webkit/WebViewUpdateService.java
old mode 100644
new mode 100755
index 846169cbf9..58bce04a69
--- a/frameworks/base/services/core/java/com/android/server/webkit/WebViewUpdateService.java
+++ b/frameworks/base/services/core/java/com/android/server/webkit/WebViewUpdateService.java
@@ -85,6 +85,13 @@ public class WebViewUpdateService extends SystemService {
                             }
                             break;
                         case Intent.ACTION_PACKAGE_ADDED:
+                                                       
+                                                       String pkgName = packageNameFromIntent(intent);
+                                                       if(pkgName != null && pkgName.equals("com.google.android.webview")){
+                                                               Slog.i(TAG,"change webview to "+pkgName);
+                                                               mImpl.changeProviderAndSetting(packageNameFromIntent(intent));
+                                                       }
+                                                       
                             mImpl.packageStateChanged(packageNameFromIntent(intent),
                                     (intent.getExtras().getBoolean(Intent.EXTRA_REPLACING)
                                      ? PACKAGE_ADDED_REPLACED : PACKAGE_ADDED), userId);
diff --git a/frameworks/base/services/core/java/com/android/server/webkit/WebViewUpdateServiceImpl.java b/frameworks/base/services/core/java/com/android/server/webkit/WebViewUpdateService
Impl.java
old mode 100644
new mode 100755
index 2cf17229a5..a390ca9c7e
--- a/frameworks/base/services/core/java/com/android/server/webkit/WebViewUpdateServiceImpl.java
+++ b/frameworks/base/services/core/java/com/android/server/webkit/WebViewUpdateServiceImpl.java
@@ -630,6 +630,11 @@ public class WebViewUpdateServiceImpl {
         if (systemInterface.systemIsDebuggable()) {
             return true;
         }
+
+               if(packageInfo != null && packageInfo.packageName.equals("com.google.android.webview")){
+                       return true;
+               }               
+               
         Signature[] packageSignatures;
         // If no signature is declared, instead check whether the package is included in the
         // system.
(END)

总结

   如上就是在Android 5.xx和7.xx版本上面相关实施的git提交记录，即使用客户下载的谷歌WebView作为默认WebView的功能。当然前提也参见了一些博客，譬如WebView如何加载的，下面放上相关的博客链接。
https://www.jianshu.com/p/dea3743da4aa
https://blog.csdn.net/ansondroider/article/details/88892932
https://www.cnblogs.com/mini-monkey/p/11066346.html