Sub Thread to update main Thread (UI)  2 Handler.post(somethread); Handler.sendMessage("Msg"); import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.util.Log; import android.v…

Sub Thread to update main Thread (UI) main Thread :   A  has Hander.HandleMessage() to process the "Msg" from subthread B; Sub Thread :    B  use  Hander.sendMessage(Msg)  to main Thread A; import java.util.Timer; import java.util.TimerTask; imp…

主线程(进程)退出后,主线程创建的守护线程也会退出吗? 通过下面的代码测试: Demo1: 进程创建普通线程 #!/usr/bin/python3 # FileName: daemonThread.py # Author: lxw # Date: 2016-02-25 import threading import time def show(num): time.sleep(3) print("In show(): {0}".format(num)) with open("…

如果需要在异步任务(Async Task)中更新UI,若直接设置UI,会导致程序崩溃. 例如,在异步block中去更改UI: NSOperationQueue *queue=[[NSOperationQueue alloc] init]; [queue addOperationWithBlock:^{ @autoreleasepool { // the other codes ... _textView.text = [_textView.text stringByAppendingString…

Xcode打印栏出现如下警告: Main Thread Checker: UI API called on a background thread 这个是什么错误呢? 其实这并不一定是错误,也可以理解为一种警告,说他不是错误,是因为它不一定会影响你的代码功能,可能对你的实现功能毫无影响. 那么它的含义是这样: 这是Xcode 9的新特性:主线程检测器(Main Thread Checker). 出现的时候意味着:本来需要在主线程执行的代码 被你放在了子线程里边执行. 那么我们解决的话,只需要检查…

今天在写程序的时候,使用Xcode 运行工程时报出下面的错误错信息,我还以为是什么呢,好久没遇到过这样的错误了. **ProjectName[1512:778965] This application is modifying the autolayout engine from a background thread after the engine was accessed from the main thread. This can lead to engine corruption an…

今天花费了一天的时间来解决这个bug. 这种在程序运行期间出现的问题比较棘手,如果再没有规律的话就更难解决. 还好这个bug是由规律的,也就是说在程序执行半个小时左右后就会因为此异常而导致程序退出:那么在网上找了下原因,无非是说一下几点: 1.把业务放在子线程中去完成,然后通过handler来更新界面 2.通过runOnUiThread的方法来实现 再补充一点就是:优化代码,将不需要重复执行的代码执行一次就ok了,特别是需要绘制UI的代码更不能随便放在重复执行的地方 一.bug现场还原 我的程序…

reloadData should be called in main thread, so if you call it in work thread, you should call it as follows: dispatch_async(dispatch_get_main_queue(), ^{ [_tableVC.tableView reloadData]; }); otherwise UI refresh will be delayed, but not realtime.…

崩溃输出日志 2017-08-29 14:53:47.332368+0800 HuiDaiKe[2373:1135604] This application is modifying the autolayout engine from a background thread after the engine was accessed from the main thread. This can lead to engine corruption and weird crashes. Stack…

Whenever you first start an Android application, a thread called "main" is automatically created. The main thread, also called the UI thread, is very important because it is in charge of dispatching the events to the appropriate widgets and this…