objective-c : 构造类、继承及实例

来源：互联网发布：java中static什么意思编辑：程序博客网时间：2024/06/05 17:46

今天，我们来实现如下UML，并作为objective-c的第二个例子，介绍如何自己构造类，实现继承，并如何实例化，赋值等：

            +--------------------------+
            |       Phone              |
            |--------------------------|
            | LCDSize                |
            | Color                      |
            +-------------------------+
            | SetLCDSize          |
            | SetColor               |
            | Performance        |
            +--------------------------+
               ^                          ^
               |                            |
               |                            |
   +-----------+-------------+       +-+--------------+
   |      miPhone            |       | mPearPhone     |
   |-------------------------|         |----------------|
   |                         |              |                |
   |                         |              |                |
   +-------------------------+       |                |
   +                         |             |                |
   |                         |             +----------------+
   |                         |             +                |
   |   Performance        |       | Performance   |
   +-------------------------+       |                |
                                           +----------------+

代码实现如下：

#import <Foundation/Foundation.h>

typedef enum {
RED,
WHITE,
BLACK
}PHONECOLOR;

NSString *getColorStr(PHONECOLOR c)
{
    switch(c)
    {
        case RED: return @"red";
        case WHITE: return @"white";
        case BLACK: return @"black";
        default: return @"no color";
    }
}

@interface Phone: NSObject
{
float LCDSize;
PHONECOLOR color;
}

-(void) SetLCDSize : (float)size;
-(void) SetColor : (PHONECOLOR)c;
@end

@implementation Phone
-(void) SetLCDSize : (float)size
{
LCDSize = size;
}

-(void) SetColor : (PHONECOLOR)c
{
color = c;
}

//empty
-(void) Performance
{
}
@end

//-----iPhone "is a" Phone. it has all feature what a phone posess
@interface iPhone: Phone
@end

@implementation iPhone
-(void) Performance
{
NSLog(@"iPhone performance: LCD-%1.1f Color-%@", LCDSize, getColorStr(color));
}
@end

//----PearPhone "is a" Phone too.
@interface PearPhone: Phone
@end

@implementation PearPhone
-(void) Performance
{
NSLog(@"Pear Phone performance: LCD-%1.1f Color-%@", LCDSize, getColorStr(color));
}
@end

int main(int argc, const char *argv[])
{
    PHONECOLOR mcolor = WHITE;
    id iphone;
    iphone = [iPhone new];
    [iphone SetLCDSize: 4.0];
    [iphone SetColor: mcolor];

[iphone Performance];

    id pearphone;
    pearphone = [PearPhone new];
    [pearphone SetLCDSize: 4.5];
    mcolor = BLACK;
    [pearphone SetColor: mcolor];

[pearphone Performance];

return (0);
}