进程A（写入sp）：

SharedPreferences sharedPreferences = this.getSharedPreferences("xml_name",
                Context.MODE_WORLD_READABLE | Context.MODE_MULTI_PROCESS);
            SharedPreferences.Editor editor = sharedPreferences.edit();
            editor.putBoolean("key", true);
            editor.commit();

进程B（读取sp）：

  try {            //创建进程A的上下文
            Context phoneContext = this.createPackageContext("com.android.phone",
                                       Context.CONTEXT_IGNORE_SECURITY);
            SharedPreferences sp = phoneContext.getSharedPreferences("xml_name",
                    Context.MODE_WORLD_READABLE | Context.MODE_MULTI_PROCESS);
            int values = sp.getInt("key" , 0);
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }

需要导入的包

import android.content.pm.PackageManager;
import android.content.SharedPreferences;