understanding subnetting

execution process, it is used to respond to events initiated by users or program code or events triggered by the system. For example, if you want to input or modify the value of a field in Foxpro and then execute a program, the user-defined functions required by the valid clause and the valid clause must be created by entering code snippets. in access, a control) after the value is entered or modified, you must enter the program content during the event process of the afterupdate event attribut

In-depth understanding and application of the display attribute (1), in-depth understanding of the display Display is officially defined as the type of the box that the element should generate. This article focuses on the six commonly used values: none, block, inline, inline-block, inherit, and flex. Other tables and list-items are not recommended.I. None This element is not displayed. It is mainly distingu

Easy understanding of JavaScript status mode and easy understanding of javascript Status Mode The State mode allows an object to change its behavior when its internal State changes. The object seems to have modified its class. The usage scenarios of the Status mode are also specific, including the following:1. The behavior of an object depends on its state, and it must change its behavior according to its s

Understanding of CSS pseudo classes and understanding of CSS pseudo classes Because I have never been familiar with css pseudo classes much before, and I can't understand a piece of css code on the Internet. A: hover span. title {color: red ;.........} Currently, by querying the css manual, the css pseudo class only represents a State. a: hover only represents the tag in the suspended state of the mouse,

In-depth understanding of Android (1) -- Understanding JNI and androidjni in Android I participated in the CSDN blog Star Selection. If sunshine Xiaoqiang's blog has helped you in the past period, I hope to vote for you, every day can cast once: http://vote.blog.csdn.net/blogstar2014/details? Username = lxq_xsyu # content 1. What is JNI? JNI is the abbreviation of Java Native Interface (called locally in Ja

Handler's understanding and use 1. Handler's understanding and use Directory: Basic knowledge: 1. Android process and thread model 2. Main Android UI thread (or thread security issues) Knowledge points: Handler Introduction Handler Method 1: The subthread processes the transaction (working in the background). After the task is finished, the subthread sends a message through handler to notify the UI thread

[Android] an in-depth understanding of findViewById principles and an in-depth understanding of android I used too much, but I don't know the principle. In Xutils, instead of using the findViewById annotation, I didn't understand it at the time. After learning it step by step, we found that the findViewById efficiency is very low compared to the annotation method. The process of annotation + reflection load

references. In the heap, the right side is the memory representation of the function object, the center is the pointing of the prototype attribute of the function object, and the left side is the object instance created by the function object. The function object points to the pointer of the prototype attribute and writes dog1, dog2, and dog3 correspond to three reference changes of Dog. prototype respectively. They also have a relationship with dog1, dog2, and dog3 in the stack. (Note: Functio

Deep understanding of CSS counters and deep understanding of cssDirectory [1] Create counter [2] use counter [3] Before DEMO We are no longer familiar with counters. The list item mark in the ordered list is the counter. Create a counter There are two basic aspects for creating a counter: one is to reset the starting point of the counter, and the other is to increase it by a certain amount.Counter-reset Cou

Em understanding, em understandingEm Version: CSS1 Note: Your understanding: Note: The default browser size is 16px. The smallest font of Google Chrome is 12px. Font-size; inherited. Judgment steps: [] Check whether the font size of the element is set: Yes: So, Boder, width, height, padding, margin, line-height" , Are relative to the font size. Font-size * em value = equals to the actual value.

A deep understanding of the use of dictionary keys in Python and a deep understanding of the python dictionary Dictionary key The value in the dictionary has no restrictions. It can be any Python object, that is, from a standard object to a user-defined object. However, the keys in the dictionary have type restrictions.(1) One key cannot correspond to multiple values.One principle must be clarified: each ke

Deep understanding of linear gradient in css3 and deep understanding of css3 gradientLinear Gradient in css3Linear gradient formula: Background-image: linear-gradient ([ (Angle deg or acronyms, one or more gradient color key nodes (separated )); This method is similar to a regular expression: []: Represents a character bit. It is generally used with "|" to select a character from; |: Indicates "or", which m

Deep understanding of shared memory for inter-process communication and deep understanding of processes Shared memory is the most useful communication method between processes and the fastest IPC format. It is designed to reduce the running efficiency of other communication mechanisms. The shared memory of two different processes A and B means that the same physical memory is mapped to the process address s

Deep understanding of JS prototype and prototype chain, and deep understanding of js prototype PrototypeIt is a concept that is hard to understand in JavaScript. There are also many prototype-related attributes, the object has the prototype attribute, and the function object has the prototype attribute, the prototype object has the "constructor" attribute. I. Initial Knowledge prototypeIn JavaScript, the Pr

A deep understanding of the signals of inter-process communication and a deep understanding of Process CommunicationSignal and Signal Source Signal nature A signal is a simulation of the interrupt mechanism at the software level. In principle, a process receives a signal and the processor receives an interrupt request. The signal is asynchronous. A process does not have to wait for the signal to arrive thro

A deep understanding of the display attribute and a deep understanding of the displayDirectory [1] block [2] inline [3] inline-block [4] none [5] list-item [6] run-in [7] table [8] inline- table [9] Before table-cell [10] table-caption The display attribute is very common in web page layout, but it is often used only a few attribute values, such as block, inline-block, inline, And none. This article will de

Deep understanding of the box model, deep understanding of the ModelDirectory [1] width and height [2] padding [3] margin [4] Front of the border All document elements generate a rectangular box, called an element box, which describes the space occupied by an element in the document layout. In addition, each box affects the position and size of other element boxes. Width and height In CSS, you can set an ex

Make a summary of the contents of the first chapter:The first chapter is an overview, not to do too much detail on the description, more is the ideological doubts. What are the reasons for learning a high-level computer language or specifically learning the Java language? Always keep a scientific attitude. First of all understand why, then is the engineering how to do, and finally in the theory of mastering very familiar situations, how to do better. After learning about why Java is being learn

today is my first time since Learning programming blog, write down the weekday learning, originally these days are learning the web framework but I think it is necessary to comb the previous study. After all, learning Java before is very sketchy just for the purpose of exams. So, thinking in Java is the main book to consolidate Java from the beginning. The search for gaps and better understanding. 　　everything is an object　　 .　In C + + we know that ma

of 0x013. However, the status in registers and memory remains the value set by the addl command until the next cycle begins. [In this example, the clock is used to control the update of State elements and the value is transmitted by the combination logic. It is enough to control our SEQ to implement the computation of every instruction execution. Each time the clock changes from low to high, the processor starts to execute a new command .] 【Read operations are transmitted along these units, a