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receiver

Within a Django Model, how can I prevent a delete based on a particular field?

In the following, I have a Post model. A Post object has a status field that can be 'unpublished' or 'published'. if status is 'published', I'd like to prevent the object from being deleted, and would like to keep this logic encapsulated in the model itself. from model_utils import Choices # from Django-Model-Utils from model_utils.fields import StatusField class Post(model.Models) STATUS = Choices( ('unpublished', _('Unpublished')), ('published', _('Published')), ) ... status = StatusField(default=STATUS.unpublished) How can I do this? Overriding the delete method won't work if the objects

2021-06-27 09:30:35    分类:问答    django   django-models   overriding   receiver

C++ DGRAM 套接字获取 RECEIVER 地址(C++ DGRAM socket get the RECEIVER address)

问题 在 C++ 中, 如何获取使用 recvfrom 收到的 UDP 数据包的接收方地址。 我知道它应该是我接收数据包的同一台主机,但我需要从接收到的数据包中提取它,以验证某些内容。 我怎样才能做到这一点? 我发现这样做的一种方法是: int r = getsockopt(receiver_sock, SOL_IP, SO_ORIGINAL_DST, (struct sockaddr *) &sender_addr, (socklen_t *)&addr_len);` 但我收到错误: error: ‘SO_ORIGINAL_DST’ was not declared in this scope 我正在使用适当的标题 #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include </usr/src/linux-headers-2.6.32-21/include/linux/netfilter_ipv4.h> #include <arpa/inet.h> #include <linux/netfilter.h> 使用 netfilter_ipv4 会导致其他错误,例如未声明 INT_MIN。 但是,我认为错误是更根本的,而不是包含正确的标题。 请帮忙。 回答1 在 Linux 上

2021-06-25 05:34:58    分类:技术分享    c++   sockets   udp   receiver

getting battery level at android widget

I wrote a widget for Android and I'm trying to get the battery level. I've tried using Intent batteryIntent = context.registerReceiver(null, new IntentFilter(Intent.ACTION_BATTERY_CHANGED)); but I get the error: "IntentReceiver components are not allowed to register to receive intents" Why? the ACTION_BATTERY_CHANGED is a sticky intent and I don't register a receiver (null in the first parameter). Any workaround? Thanks.

2021-06-05 05:11:25    分类:问答    android   android-widget   battery   receiver

WakefulBroadcastReceiver is deprecated

For creating a receiver I'm extended WakefulBroadcastReceiver in my old project. But now it's deprecated. Instead of WakefulBroadcastReceiver which Receiver I should use now and how to convert below code with new method? Here is my code: public class TaskFinishReceiver extends WakefulBroadcastReceiver { private PowerManager mPowerManager; private PowerManager.WakeLock mWakeLock; @Override public void onReceive(Context context, Intent intent) { mPowerManager = (PowerManager) context.getSystemService(Context.POWER_SERVICE); turnOnScreen(); Intent wakeIntent = new Intent(); wakeIntent

2021-05-24 12:25:33    分类:问答    android   android-broadcastreceiver   receiver   powermanager

How to access Switch button that is declared in MainActivity(layout) in BroadcastReceivers

I have a task in which i have to change state of Switch button when airplane mode is ON/OFF. I have a main activity in which i declared Switch Button and i want to Change the state on/off of Switch from BroadcastReceiver Class Receiver public class MyReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { boolean isAirplaneModeOn = intent.getBooleanExtra("state", false); if(isAirplaneModeOn){ What Should i do ? } } } layout_main_activity <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http:/

2021-05-14 20:58:56    分类:问答    java   android   widget   broadcastreceiver   receiver

Android-蓝牙发现找不到任何设备(Android - Bluetooth discovery doesn't find any device)

问题 我目前正在开发一个小应用程序,以开始使用Bluetooth Android API可以提供的服务。 编辑->答案: 该问题似乎是由于特定的Nexus 5设备引起的。 好像他们的蓝牙接收器工作不正常。 以下解决方案适用于其他设备 评论: 我在这里阅读了文档:http://developer.android.com/guide/topics/connectivity/bluetooth.html以及本教程的以下源代码http://www.londatiga.net/it/programming / android / how-to-programmatically-scan-or-discover-android-bluetooth-device /位于github下的/ lorensiuswlt / AndroBluetooth下我已经完成了几乎所有我感兴趣的功能(例如检查适配器的存在,启用/禁用蓝牙,查询配对的设备,设置可发现的适配器)。 问题: 即使我从Nexus 5的“设置” /“蓝牙”中找到了设备,当我启动.onDiscovery()方法时,实际上没有找到任何设备。 这是我的处理方式: public class MainActivity extends AppCompatActivity { private BluetoothAdapter

2021-05-08 23:24:02    分类:技术分享    android   bluetooth   receiver

Is it better code practice to register a receiver in manifest or in code?

I'm writing a simple broadcast receiver. I've registered receivers in both the manifest and in the code before. For my purposes this is a simple receiver that doesn't need to do anything fancy. Is there a reason to choose one method over the other in this case? Is registering the receiver in the manifest more efficient (executes faster)? Or are they both basically the same? I'm asking because the application I'm writing needs to be very efficient, and I haven't been able to find good information on the practical difference between the two methods. I'm trying to follow whatever is the best

2021-05-07 18:24:38    分类:问答    java   android   manifest   receiver

BOOT_COMPLETED not called on Honeycomb after export

I have a very weird problem, and none of the questions already on the website have an answer or the same problem. I have an app that receives BOOT_COMPLETED. I made sure it could receive the intent by setting android:installLocation to internalOnly. I have a Log.Debug in my OnBoot class, confirming wether or not it was called. I have two devices, an Android 2.2, and a Honeycomb. On android 2.2, it works fine, but Honeycomb... If I install the application on the honeycomb tablet with eclipse's "run" button, onBoot is called when the tablet boots. If I install the application on the honeycomb

2021-04-27 08:02:50    分类:问答    android   receiver   bootcompleted

Android DownloadManager获取文件名(Android DownloadManager get filename)

问题 在我的应用程序中,您可以下载一些文件。 我使用Android DownloadManager类进行下载。 下载完成后,应该显示一条消息,说明文件已下载。 问题是,可能同时有2,3或4个下载。 我的BroadcastReceiver代码如下所示: receiver_complete = new BroadcastReceiver(){ @Override public void onReceive(Context context, Intent intent) { String action = intent.getAction(); if (action.equals(DownloadManager.ACTION_DOWNLOAD_COMPLETE) ){ Toast.makeText(MainActivity.this, MainActivity.this.getString(R.string.download_finished, "Here should be the name", Toast.LENGTH_SHORT).show(); } } }; 如何获得完成下载的当前文件名? 非常感谢你。 回答1 我认为您想在if块中放入类似的内容。 用DownloadManager实例替换YOUR_DM 。 Bundle extras = intent.getExtras()

2021-04-23 11:06:20    分类:技术分享    java   android   broadcastreceiver   android-download-manager   receiver

android:enable and services

I m currently learning how create and use services on android. I looked on the android SDK for further help and i found the android:enable=[true | false]. in the SDK is said that: The and attributes must both be "true" (as they both are by default) for the service to be enabled. If either is "false", the service is disabled; it cannot be instantiated. So i would like to know what is the interest of/ why (in general) setting the application enables as "false". setting the service enable as "false". I say that if we put service enable as false there is no way to call that service, so why we

2021-04-23 04:16:28    分类:问答    android   service   receiver