项目中有时候需要保存一些永久变量，使用系统数据库是一个好的选择，但是如果该变量需要在第三方APP中访问，就还需要解决要解决权限问题。
下面以变量notification_panel_enable，bool类型为例
一、添加变量
首先要进行变量初始化，一般位于SettingsProvider
定义变量，方便引用
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
public final class Settings {
*/
public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/global");
+ //bianjb 状态栏下拉开关
+ public static final String NOTIFICATION_PANEL_ENABLE = "notification_panel_enable";
+
初始化变量
diff --git a/packages/SettingsProvider/res/values/defaults.xml
<resources>
+ <!--bianjb 添加状态栏下拉开关 -->
+ <bool name="notification_panel_enable">true</bool>
diff --git a/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
class DatabaseHelper extends SQLiteOpenHelper {
try {
stmt = db.compileStatement("INSERT OR IGNORE INTO global(name,value)"
+ " VALUES(?,?);");
+ //bianjb 添加状态栏下拉开关
+ loadBooleanSetting(stmt, Settings.Global.NOTIFICATION_PANEL_ENABLE,
+ R.bool.notification_panel_enable);
二、解决第三方APP读写的权限问题
diff --git a/packages/SettingsProvider/src/com/android/providers/settings/SettingsProvider.java
@@ -1249,18 +1250,23 @@ public class SettingsProvider extends ContentProvider {
private boolean mutateGlobalSetting(String name, String value, String tag,
boolean makeDefault, int requestingUserId, int operation, boolean forceNotify,
int mode) {
- // Make sure the caller can change the settings - treated as secure.
- enforceWritePermission(Manifest.permission.WRITE_SECURE_SETTINGS);
String pkg = "com.android.settings"; //数据写入时使用系统settings应用的包名，系统会进行调用进程的包名判断
if(!"notification_panel_enable".equals(name)){ //bianjb 自定义数据不进行权限验证
pkg = "";
// Make sure the caller can change the settings - treated as secure.
enforceWritePermission(Manifest.permission.WRITE_SECURE_SETTINGS);
}
//下面修改在插入操作时使用上面预设的包名，绕过包名验证
@@ -1268,7 +1274,7 @@ public class SettingsProvider extends ContentProvider {
case MUTATION_OPERATION_INSERT: {
return mSettingsRegistry.insertSettingLocked(SETTINGS_TYPE_GLOBAL,
UserHandle.USER_SYSTEM, name, value, tag, makeDefault,
- getCallingPackage(), forceNotify, CRITICAL_GLOBAL_SETTINGS);
+ "".equals(pkg)?getCallingPackage():pkg, forceNotify, CRITICAL_GLOBAL_SETTINGS);
}
三、变量读写
//写
Settings.Global.putInt(mContext.getContentResolver(),Settings.Global.NOTIFICATION_PANEL_ENABLE,1);
//读
Settings.Global.getInt(mContext.getContentResolver(),Settings.Global.NOTIFICATION_PANEL_ENABLE, 1)
