获取当前上下文Activity

获取当前上下文，用于显示dialog或弹出toast
public static Activity getGlobleActivity(){
Class<?> activityThreadClass;
try {
activityThreadClass = Class.forName("android.app.ActivityThread");
Object activityThread = activityThreadClass.getMethod("currentActivityThread").invoke(null);
Field activitiesField = activityThreadClass.getDeclaredField("mActivities");
activitiesField.setAccessible(true);
Map<?, ?> activities = (Map<?, ?>) activitiesField.get(activityThread);
for(Object activityRecord:activities.values()){
Class<? extends Object> activityRecordClass = activityRecord.getClass();
Field pausedField = activityRecordClass.getDeclaredField("paused");
pausedField.setAccessible(true);
if(!pausedField.getBoolean(activityRecord)) {
Field activityField = activityRecordClass.getDeclaredField("activity");
activityField.setAccessible(true);
Activity activity = (Activity) activityField.get(activityRecord);
return activity;
}
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}