Android 12 (InputMethodManagerService) 替换默认输入法为Pinyin输入法

1.问题场景

由于系统自带的Latin输入法不支持遥控器操作，需要替换为RK的拼音输入法。

2. 替换步骤

1）将LatinIME从mk中删除，让系统编译的时候不编译该apk

--- a/Android/build/make/target/product/handheld_product.mk
+++ b/Android/build/make/target/product/handheld_product.mk
@@ -23,7 +23,6 @@ $(call inherit-product, $(SRC_TARGET_DIR)/product/media_product.mk)
 # /product packages
 PRODUCT_PACKAGES += \
     Browser2 \
-    LatinIME \
     preinstalled-packages-platform-handheld-product.xml \
     SettingsIntelligence \
     frameworks-base-overlays

2）添加PinyinIME的编译预装

--- a/Android/device/rockchip/common/modules/rockchip_apps.mk
+++ b/Android/device/rockchip/common/modules/rockchip_apps.mk
@@ -20,3 +20,5 @@
 #     RkVideoPlayer \
 #     RkExplorer \
 #     StressTest
+PRODUCT_PACKAGES += \
+       PinyinIME

3）设置PinyinIME为默认输入法。这一步在网上搜了几个方案 ，但是都有些问题，后面自己试验用如下方式可以设置成功，即在InputManagerServices.java的buildInputMethodListLocked函数中添加设置默认输入法值的动作

+++ b/Android/frameworks/base/services/core/java/com/android/server/inputmethod/InputMethodManagerService.java
@@ -4560,6 +4560,26 @@ public class InputMethodManagerService extends IInputMethodManager.Stub
             Slog.e(TAG, "buildInputMethodListLocked is not allowed until system is ready");
             return;
         }
+        String defaultIme = Settings.Secure.getString(mContext
+             .getContentResolver(), Settings.Secure.DEFAULT_INPUT_METHOD);
+        if ( defaultIme == null ) {
+            final Resources res = mContext.getResources();
+            try{
+                String myIME = "com.android.inputmethod.pinyin/.PinyinIME";
+                if ( myIME != null && myIME.length() > 0 )
+                {
+                    Settings.Secure.putString( mContext.getContentResolver(),
+                            Settings.Secure.DEFAULT_INPUT_METHOD,
+                            myIME );
+                    Settings.Secure.putString( mContext.getContentResolver(),
+                        Settings.Secure.ENABLED_INPUT_METHODS,
+                        myIME );
+                }
+            } catch( Exception e ) {
+            }
+        }