Objective-C 多線程: Grand Central Dispatch(GCD)

Serial	sync嵌套會死鎖, 外部的sync block會等待內部的sync block完成才結束, 但內部的永遠執行不到
	GCD_TEST[45149:303] HELLO
	GCD_TEST[45149:1a03] async:{name = (null), num = 2}
	-
Concurrent	怎麼嵌套都不會死鎖, 因為block沒有順序依賴關係
	GCD_TEST[45167:303] HELLO
	GCD_TEST[45167:303] sync:{name = (null), num = 1}
	GCD_TEST[45167:1503] async:{name = (null), num = 2}
	GCD_TEST[45167:1503] sync-async:{name = (null), num = 2}
	GCD_TEST[45167:1a03] async-async:{name = (null), num = 3}
	GCD_TEST[45167:303] sync-sync:{name = (null), num = 1}
	GCD_TEST[45167:1503] sync-async:{name = (null), num = 2}
	-
Main	async 和 sync 相同, 都在主線程, 怎麼嵌套都會死鎖, 只用sync也無法執行, 因為main queue一直有任務在執行
	GCD_TEST[45083:303] HELLO
	-
Global	系統共用的queue, 效果同Concurrent
	GCD_TEST[45187:303] HELLO
	GCD_TEST[45187:303] sync:{name = (null), num = 1}
	GCD_TEST[45187:1a03] async:{name = (null), num = 2}
	GCD_TEST[45187:1a03] sync-async:{name = (null), num = 2}
	GCD_TEST[45187:1f03] async-async:{name = (null), num = 3}
	GCD_TEST[45187:303] sync-sync:{name = (null), num = 1}
	GCD_TEST[45187:1a03] sync-async:{name = (null), num = 2}

	//
	// GCD_Test.m
	// GCD_TEST
	//
	// Created by fengyi on 2014/11/19.
	// Copyright (c) 2014年 fytsai. All rights reserved.
	//
	#import "GCD_Test.h"
	@implementation GCD_Test
	-(void) gcd_main_queue{
	dispatch_queue_t main_queue = dispatch_get_main_queue();
	NSLog(@"HELLO");
	dispatch_async(main_queue, ^{
	NSLog(@"async:%@",[NSThread currentThread]);
	dispatch_async(main_queue, ^{
	NSLog(@"async-async:%@",[NSThread currentThread]);
	});
	dispatch_sync(main_queue, ^{
	NSLog(@"sync-async:%@",[NSThread currentThread]);
	});
	});
	dispatch_sync(main_queue, ^{
	NSLog(@"sync:%@",[NSThread currentThread]);
	dispatch_sync(main_queue, ^{
	NSLog(@"sync-sync:%@",[NSThread currentThread]);
	});
	dispatch_async(main_queue, ^{
	NSLog(@"sync-async:%@",[NSThread currentThread]);
	});
	});
	}
	-(void) gcd_concurrent_queue{
	dispatch_queue_t concurrent_queue = dispatch_queue_create("fytsai", DISPATCH_QUEUE_CONCURRENT);
	NSLog(@"HELLO");
	dispatch_async(concurrent_queue, ^{
	NSLog(@"async:%@",[NSThread currentThread]);
	dispatch_async(concurrent_queue, ^{
	NSLog(@"async-async:%@",[NSThread currentThread]);
	});
	dispatch_sync(concurrent_queue, ^{
	NSLog(@"sync-async:%@",[NSThread currentThread]);
	});
	});
	dispatch_sync(concurrent_queue, ^{
	NSLog(@"sync:%@",[NSThread currentThread]);
	dispatch_sync(concurrent_queue, ^{
	NSLog(@"sync-sync:%@",[NSThread currentThread]);
	});
	dispatch_async(concurrent_queue, ^{
	NSLog(@"sync-async:%@",[NSThread currentThread]);
	});
	});
	}
	-(void) gcd_serial_queue{
	dispatch_queue_t serial_queue = dispatch_queue_create("fytsai", DISPATCH_QUEUE_SERIAL);
	NSLog(@"HELLO");
	dispatch_async(serial_queue, ^{
	NSLog(@"async:%@",[NSThread currentThread]);
	dispatch_async(serial_queue, ^{
	NSLog(@"async-async:%@",[NSThread currentThread]);
	});
	dispatch_sync(serial_queue, ^{
	NSLog(@"sync-async:%@",[NSThread currentThread]);
	});
	});
	dispatch_sync(serial_queue, ^{
	NSLog(@"sync:%@",[NSThread currentThread]);
	dispatch_sync(serial_queue, ^{
	NSLog(@"sync-sync:%@",[NSThread currentThread]);
	});
	dispatch_async(serial_queue, ^{
	NSLog(@"sync-async:%@",[NSThread currentThread]);
	});
	});
	}
	-(void) gcd_global_queue{
	dispatch_queue_t global_queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
	NSLog(@"HELLO");
	dispatch_async(global_queue, ^{
	NSLog(@"async:%@",[NSThread currentThread]);
	dispatch_async(global_queue, ^{
	NSLog(@"async-async:%@",[NSThread currentThread]);
	});
	dispatch_sync(global_queue, ^{
	NSLog(@"sync-async:%@",[NSThread currentThread]);
	});
	});
	dispatch_sync(global_queue, ^{
	NSLog(@"sync:%@",[NSThread currentThread]);
	dispatch_sync(global_queue, ^{
	NSLog(@"sync-sync:%@",[NSThread currentThread]);
	});
	dispatch_async(global_queue, ^{
	NSLog(@"sync-async:%@",[NSThread currentThread]);
	});
	});
	}
	@end

view raw GCD_Test.m hosted with ❤ by GitHub

javascript function.call()

var a = function(a,b,c){
  console.log(this.a);
  console.log(this.b);
  console.log(this.c);
  console.log(a);
  console.log(b);
  console.log(c);
}
 
var b = {
  a:123,
  b:456,
  c:789
}
 
a.call(b,1,2,3)
//  output:
//  123
//  456 
//  789 
//  1
//  2
//  3
 
a.apply(b,[1,2,3])
//  output:
//  123
//  456 
//  789 
//  1
//  2
//  3

Android 模擬按鍵點擊

Reference:
http://developer.android.com/reference/android/app/Instrumentation.html



Code:

Instrumentation.sendKeyDownUpSync(key_code);

KeyEvent  Key Code Mapping:
http://developer.android.com/reference/android/view/KeyEvent.html

HTML5的觸控事件

螢幕被點擊後依序會觸發三個事件:

touchStart	開始
touchMove	移動
touchEnd	結束

觸控點列表:

touches	screen上所有的觸控點
targetTouches	元素上所有觸控點
changedTouches	該次事件相關的觸控點

Touch的屬性:

identifier	第n個觸控點(從0開始)
target	元素
pageX/Y	該頁面的x/y距離
clientX/Y	該頁面的x/y距離(不包含滾動距離)
screenX/Y	螢幕的x/y距離

效果:

Demo:

Source Code:

	<!doctype html>
	<html xmlns="http://www.w3.org/1999/xhtml">
	<head>
	<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
	<title>Touch</title>
	</head>
	<body>
	<canvas id="MyCanvas" style="border: #CCC solid 1px;">
	<script>
	function $(id){
	return document.getElementById(id);
	}
	var canvas = $("MyCanvas");
	var context = canvas.getContext("2d");
	function getTouchPoint(e){
	var pageX = e.targetTouches[0].pageX;
	var pageY = e.targetTouches[0].pageY;
	return {
	x: pageX - e.target.offsetLeft,
	y: pageY - e.target.offsetTop
	}
	}
	canvas.addEventListener("touchstart",function(e){
	context.beginPath();
	var point = getTouchPoint(e);
	context.moveTo(point.x,point.y);
	});
	canvas.addEventListener("touchmove",function(e){
	e.preventDefault();
	var point = getTouchPoint(e);
	context.lineTo(point.x,point.y);
	context.strokeStyle = 'red';
	context.stroke();
	});
	canvas.addEventListener("touchend",function(e){
	context.save();
	});
	</script>
	</body>
	</html>

view raw Touch.html hosted with ❤ by GitHub

JavaScript: Falsy Values

Falsy Values:

0: false

false: false

null: false

undefined: false

NaN: false

"": false

Shell Script

	#!/bin/bash
	# if else
	if [ 2 = 1 ] ;
	then
	echo "2=1"
	elif [ 2 = 3 ] ;
	then
	echo "2=3"
	else
	echo "else"
	fi
	# for loop
	for word in "aaa" "bbb" "ccc" "ddd"
	do
	echo $word
	done
	# while loop
	i=0
	while [ $i -lt 5 ] ;
	do
	echo $i
	((i++))
	done
	# until loop
	i=0
	until [ $i -gt 4 ] ;
	do
	echo $i
	((i++))
	done
	# switch
	echo "press a key"
	read key
	case "$key" in
	[A-Z]) echo "Upper";;
	[a-z]) echo "Lower";;
	[0-9]) echo "Number";;
	*) echo "others"
	esac
	# list all file
	for i in *
	do
	if [ -f "$i" ] ; then
	echo "$i is a regular file"
	elif [ -d "$i" ] ; then
	echo "$i is a directory"
	fi
	done
	function check() {
	if [ -f "$1" ] ; then
	echo "$i is a regular file"
	elif [ -d "$1" ] ; then
	echo "$i is a directory"
	fi
	}
	for i in *
	do
	check $i
	done

view raw gistfile1.ps1 hosted with ❤ by GitHub

Android 用 adb shell啟動 Activity

在app中intent 可以透過Action或是Activity Name來啟動新的Activity
用adb shell 也同樣可以做到

1. 用Action啟動 activity

adb shell am start -a android.intent.action.MAIN

可以再加上category


adb shell am start -a android.intent.action.MAIN -c android.intent.category.HOME

2. 用activity name 啟動 activity
注意前面要加上package name
格式：am start -n package name / activity name  )

am start -n com.demo.browser/com.demo.browser.BrowserActivity