业务练习（矩形）
本帖最后由 Sian 于 2014-1-18 18:31 编辑需求分析：
写一个Rectangle类，具备以下属性：位置（origin）、长（width）、宽（height）
要求提供：初始化方法、工厂方法、业务方法（移动位置、求周长、求面积）
程序实现：说明：我们程序实现中写两个类SAPoint与SARectangle，SAPoint专为矩形提供位置服务（矩形的一个属性）
SAPoint.h
//
//SAPoint.h
//Rectangle
//
//Created by yusian on 14-1-18.
//Copyright (c) 2014年 yusian. All rights reserved.
//
#import <Foundation/Foundation.h>
@interface SAPoint : NSObject
@property int x;
@property int y;
- (id) init;
- (id) initWithX:(int)x andY:(int)y;
+ (id) pointWithX:(int)x andY:(int)y;
- (void) show;
@end
SAPoint.m
//
//SAPoint.m
//Rectangle
//
//Created by yusian on 14-1-18.
//Copyright (c) 2014年 yusian. All rights reserved.
//
#import "SAPoint.h"
@implementation SAPoint
- (id) init
{
if (self = ) {
_x = 1;
_y = 1;
}
return self;
}
- (id) initWithX:(int)x andY:(int)y
{
if (self = ) {
self.x = x;
self.y = y;
}
return self;
}
+ (id) pointWithX:(int)x andY:(int)y
{
return [ initWithX:(int)x andY:(int)y];
}
- (void) show{
NSLog(@"The position is (%d,%d)",_x,_y);
}
- (void) dealloc
{
NSLog(@"SAPoinr is dealloc");
;
}
@endSARectangle.h
//
//SARectangle.h
//Rectangle
//
//Created by yusian on 14-1-18.
//Copyright (c) 2014年 yusian. All rights reserved.
//
#import <Foundation/Foundation.h>
#import "SAPoint.h"
@interface SARectangle : NSObject
@property int width;
@property int height;
@property (assign) SAPoint *origin;
- (id) initWithPoint:(SAPoint *)origin andWidth:(int)width andHeight:(int)height;
+ (id) rectangleWithPoint:(SAPoint *)origin andWith:(int)width andHeight:(int)height;
- (void) show;
- (void) moveToX:(int)x andY:(int)y;
- (int) perimeter;
- (void) perimeterPrint;
- (int) area;
- (void) areaPrint;
@endSARectangle.m
//
//SARectangle.m
//Rectangle
//
//Created by yusian on 14-1-18.
//Copyright (c) 2014年 yusian. All rights reserved.
//
#import "SARectangle.h"
@implementation SARectangle
- (id) initWithPoint:(SAPoint *)point andWidth:(int)width andHeight:(int)height
{
self = ;
if (self) {
self.origin = point;
self.width = width;
self.height = height;
}
return self;
}
+ (id) rectangleWithPoint:(SAPoint *)point andWith:(int)width andHeight:(int)height
{
return [ initWithPoint:(SAPoint *)point andWidth:(int)width andHeight:(int)height];
}
- (void) moveToX:(int)x andY:(int)y
{
_origin.x = x;
_origin.y = y;
NSLog(@"The new position is (%d,%d)",_origin.x,_origin.y);
}
- (int) perimeter
{
return (self.width+self.height)*2;
}
- (void) perimeterPrint
{
NSLog(@"The Perimeter is %d",self.perimeter);
}
- (int) area
{
return self.width*self.height;
}
- (void) areaPrint
{
NSLog(@"The area is %d",self.area);
}
- (void) show
{
NSLog(@"The rectangle position is (%d,%d) , Width is %d , Height is %d",_origin.x,_origin.y,self.width,self.height);
}
- (void) dealloc
{
NSLog(@"SARectangle is dealloc");
;
;
}
@end
main.m
//
//main.m
//Rectangle
//
//Created by yusian on 14-1-18.
//Copyright (c) 2014年 yusian. All rights reserved.
//
#import <Foundation/Foundation.h>
#import "SAPoint.h"
#import "SARectangle.h"
int main(int argc, const char * argv[])
{
@autoreleasepool {
SAPoint * point = ;//工厂方法
;
SARectangle * rectangle = ;
;
;
;
;
;
}
return 0;
}
输出结果：
2014-01-18 18:25:40.178 Rectangle The position is (2,4)
2014-01-18 18:25:40.179 Rectangle The rectangle position is (2,4) , Width is 10 , Height is 20
2014-01-18 18:25:40.180 Rectangle The Perimeter is 60
2014-01-18 18:25:40.180 Rectangle The area is 200
2014-01-18 18:25:40.180 Rectangle The new position is (3,5)
2014-01-18 18:25:40.181 Rectangle SARectangle is dealloc
2014-01-18 18:25:40.181 Rectangle SAPoinr is dealloc
Program ended with exit code: 0
本帖最后由 Sian 于 2014-1-19 16:44 编辑
该程序还存在内存管理问题：
在声明SAPoint对象时，没有将SAPoint进行内存管理
因此，在@property (assign) SAPoint * origin 时需要优化，最简单的方法在声明时使用retain属性
修改成：@property (retain)SAPoint * origin;
main.m中创建point后，将point被调用后，负责创建point的指针有责任将point释放，因此需要在
ARectangle * rectangle = ;后加上;
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