Set a background picture[Self.navigationController.navigationBar Setbackgroundimage:imag Forbarmetrics:uibarmetricsdefault];button to define the background text or event you wantUibarbuttonitem *leftbarbutton = [[Uibarbuttonitem alloc] Initwithcustomview:button];Self.navigationItem.leftBarButtonItem = Leftbarbutton;[Leftbarbutton release];Specific implementation:[Self.navigationitem settitle:@ "notice details"];Self.navigationController.navigationBarHidden = NO;[Self.navigationController.navigat
, declare it between the @interface class name: Parent class Name {} @end, and be able to call outside the classCommon errors:(1) @interface @end and @implementation @end cannot be nested with(2) Only the declaration of the class has no implementation of the class(3) Missing write @end(4) member variable not written in {}(5) The declaration of the method is written in {}(6) method cannot be called like a function(7) member variables and methods can not be modified with static and other keywords,
Once you have defined this macro#define CC_SYNTHESIZE_READONLY (VarType, VarName, Funname)Protected:vartype VarName;Public:inline Virtual VarType get# #funName (void) const {return varName;}Execute the following statementCc_synthesize_readonly (canavigationcontroller*, M_prootnavigationcontroller, Rootnavigationcontroller);Equivalent to performing the followingProtectedcanavigationcontroller* M_prootnavigationcontroller;Inline canavigationcontroller* Getrootnavigationcontroller (return m_prootna
in theObject oriented
(OOP) language, a class can have one or more subclasses, and each class has at least one public method interface that is accessed as an external code. and abstract method is to facilitate the introduction of inheritance, and now take a look atAbstract class
and how the abstract methods are defined and their characteristics.
What is an abstract method? The method we define in our class is the abstract method, without the method body, the so-called No method is the method d
This article mainly introduces the definition and inheritance usage of php classes, and analyzes the basic definition and inheritance usage skills of php classes, for more information about the definitions and inheritance usage of php classes, see the examples in this article. Share it with you for your reference. The details are as follows:
"." Age: ". $ this-> age;} function _ tostring () {return" name: ". $ this-> name .""." Age: ". $ this-> age;
This article mainly introduces the definition and inheritance usage of php classes, and analyzes the basic definition and inheritance usage skills of php classes, for more information about the definitions and inheritance usage of php classes, see the examples in this article. Share it with you for your reference. The details are as follows:
"." Age: ". $ this-> age;} function _ tostring () {return" name: ". $ this-> name .""." Age: ". $ this-> age;
This article mainly introduces the Python iterator definition and simple usage, and analyzes the concept, principle, creation and use of the iterator in the form of an instance, and the friends can refer to the following
The examples in this article describe Python iterator definitions and simple usages. Share to everyone for your reference, as follows:
First, what is an iterator
Iterations, as the name implies, are repeated several times (as is now
several prerequisites for its appearance:
1. the array attribute must be defined for the class and initialized when the class variable is defined;
2. it must be before the explicit array key, after the implicit array key, the implicit array key overwrites the value of the display array key at the same position as itself; if the implicit array key is before, after the explicit array key is defined, overwriting will occur, regardless of the version;
3. the explicit array key must be a constant
The standard is to support a two-class definition, just as li.classname defines an attribute of Li with classname, and a space in the middle is defined as the element that has classname in the Li child element.Class selector and write no space, like Li.classname, which can extend and write, ID and write (because the ID is unique, and write basically no meaning); ID and class and write should be able to form a control element style selector.Example:. cb-disable.selected corresponds to If there ar
Inline functions with the parameter macro definition and the inline decoration are replaced by the function body with a macro call or function call at compile time. The benefit of this is to reduce the time it takes to call the function.For example:Introduction to the algorithm when it comes to heap ordering, the good heap sort implementation is generally to leave (i), right (i), the implementation of the Parent (i) through a macro definition or inline function, this is because when we use heap
As the saying goes: "A good memory is worse than a bad keyboard ". I recently read 《C ++ProgramDesign tutorial. I have some insights on the differences between the function prototype and the function definition in the function call. I will record it and study it later.
When defining a function, the program pushes the parameters to be passed into the stack. The specific parameter sequence is related to the compiler. Then Call The address of the called function. Sometimes the program p
1. About NSLog Output/** * When Xcode is release does not output, for debug output * * @param ... * * @return * /#ifndef __optimize__#define NSLog (...) NSLog (__va_args__)/** * You can see the class name, method, and number of rows when printing * *///#define NSLOG (FMT,...) NSLog (@ "%s [line%d]" FMT), __pretty_function__, __line__, # # __va_args__); #else # define NSLOG (...) {} #endif2. Color#define RGB_COLOR (r,g,b) [Uicolor colorwithred: (r)/255.0 Green: (g)/255.0 Blue: (b)/255.0 alph
Reprinted from https://my.oschina.net/cdzsc/blog/86107In an abstract class, you can include one or more abstract methods, but in an interface (interface), all methods must be abstract and cannot have a method body, which is more "abstract" than an abstract class.1. Why only static final is defined in an interface:1.1 static (which is considered a variable at this moment) explains: because a class can implement multiple interfaces, if a class implements multiple interfaces at the same time, and e
: KeyWord;4. Use PX (pixels) as the basic unit of measurement;5. Use of hollow grid: Full angle: Chinese space half angle: nbsp;6. In the project completion package, the document and the file name all use lowercase letters, do not use the Chinese file name;7. Reduce the number of nested layers of div;8. Add alt attribute to important picture, add title to important element and truncated element;9. Use the correct annotation method;10. Non-special circumstances require performance and content sep
converted to an rvalue on X, no other function is called, and a constant expression is generated.
An ex contains an expression of a potential computed x, either discarding its results, or doing lvalue-to-rvalue conversions. struct S { static const int x = 1; }; int f() { return S::x; } // does not need define S::xOr struct S { static const int x = 1; }; void f() { S::x; } // discarded-value expression does not need define S::x
How to tell if a function needs to be definedYou need to
PHP//common functions//Generate random numbers//echo rand (1,10);//two parameters to determine the range of random numbers//datetime function//var_dump (time ());//timestamp of Unix timestamp for the current time//date_default_ Timezone_set (' PRC '),//echo date ("Y-m-d h:i:s", Time ());//format date timestamp//echo date ("y-m-d h:i:s");//omit 2nd parameter get current time//array/ Features: can store any type of data, can be discontinuous, can be indexed, or can be associated//definition array
1. Double quotes can parse the variable "string $a" normally2. Single quotes cannot parse the variable ' string $a ' normally3. Print only the preceding string:4.{$url} is wrapped in curly braces and can be placed anywhere in the string. 5.N12BR function: Strings need double quotes, single quotes will not recognize \ n6. Double quotes require a lot of functionality, so the speed is slower than single quotes.7. Delimiter:the end of the delimiter Houdunwang cannot be preceded by whitespace, other
, such as arithmetic, and the host treats it as a direct quantity, as follows:Copy CodeThe code is as follows:var a = ten + function () {return 5;}();Exaggerate a little, as follows:Copy CodeThe code is as follows:(function () {Alert (1);} ) ( );(function () {Alert (2);} ( ) );void function () {Alert (3);}()0, function () {Alert (4);}();-function () {Alert (5);}();+function () {Alert (6);}();!function () {Alert (7);}();~function () {Alert (8);}();typeof function () {Alert (9);}();There are many
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