大约有 15,000 项符合查询结果（耗时：0.0431秒） [XML]
使用App Inventor 2 控制物联网设备/低功耗蓝牙设备(BLE) · App Inventor 2 中文网
...接。 因此，我们开发蓝牙 LE 组件是为了解决物联网连接问题。
三． 技术方法
BluetoothLE 组件是 MIT App Inventor 的新颖补充。 如图 4 所示，在 MIT App Inventor 平台上创建时，BLE 组件可以作为移动应用程序的一部分实现。 然后，该...
Convert objective-c typedef to its string equivalent
...Type.JSON sytax. FormatType is a type and the enum values (e.g. JSON, XML, etc.) are values that you can assign to that type.
share
|
improve this answer
|
follow
...
What is the difference between concurrent programming and parallel programming?
...O bound but not always, e.g. concurrent garbage collectors are entirely on-CPU. The pedagogical example of a concurrent program is a web crawler. This program initiates requests for web pages and accepts the responses concurrently as the results of the downloads become available, accumulating a set ...
When and why are database joins expensive?
...ires retrieval of only the keys. In practice, not even the key values are fetched: the key hash values are used for join comparisons, mitigating the cost of multi-column joins and radically reducing the cost of joins involving string comparisons. Not only will vastly more fit in cache, there's a lot...
Selenium WebDriver: Wait for complex page with JavaScript to load
...bserve its behaviour and track some of its variables on window or document etc. This solution, however, is not for everyone and can be used only by you and only on a limited set of pages.
Your solution by observing the HTML code and whether it has or hasn't been changed for some time is not bad (als...
C# DateTime.Now precision
...
Why would DateTime.Now be made less precise than what most CPU clocks could handle?
A good clock should be both precise and accurate; those are different. As the old joke goes, a stopped clock is exactly accurate twice a day, a clock a minute slow is never accurate at any time. Bu...
Why does JPA have a @Transient annotation?
...ystem uses tools to generate entities from database. (Hibernate has those, etc...)
Now, suppose that by your business logic you need a particular field NOT to be persisted. You have to "configure" your entity in a particular way.
While Transient keyword works on an object - as it behaves within a j...
Increasing the maximum number of TCP/IP connections in Linux
... eth0 txqueuelen 5000
echo "/sbin/ifconfig eth0 txqueuelen 5000" >> /etc/rc.local
Similarly bump up the values for net.core.netdev_max_backlog and net.ipv4.tcp_max_syn_backlog. Their default values are 1000 and 1024 respectively.
sysctl net.core.netdev_max_backlog=2000
sysctl net.ipv4.tcp_m...
Debug vs. Release performance
...oven to be invariants
code written under #debug directive is not included, etc.
The rest is up to the JIT.
Full list of optimizations here courtesy of Eric Lippert.
share
|
improve this answer
...
Should I use Vagrant or Docker for creating an isolated environment? [closed]
...ctivity benefits:
Vagrant can launch VirtualBox, VMware, AWS, OpenStack, etc. machines. It doesn't matter what you need, Vagrant can launch it. If you are using Docker, Vagrant can install Docker on any of these so you can use them for that purpose.
Vagrant is a single workflow for all your projec...