XCode 开发时,一个小BUG,记录之.

1):Rectangle.h

//

// Created by dhanzhang on 10-6-11.

// Copyright 2010 __MyCompanyName__. All rights reserved.

//

#import <Cocoa/Cocoa.h>

@interface Rectangle : NSObject {

int width;

int height;

}

-(Rectangle*) initWithWidth: (int) w height: (int) h;

-(void) setWidth: (int) w;

-(void) setHeight: (int) h;

-(void) setWidth: (int) w height: (int) h;

-(int) width;

-(int) height;

-(void) print;

@end

@interface Square: Rectangle

-(Square*) initWithSize: (int) s;

-(void) setSize: (int) s;

-(int) size;

@end

@implementation Rectangle

-(Rectangle*) initWithWidth: (int) w height: (int) h {

self = [super init];

if ( self ) {

[self setWidth: w height: h];

}

return self;

}

-(void) setWidth: (int) w {

width = w;

}

-(void) setHeight: (int) h {

height = h;

}

-(void) setWidth: (int) w height: (int) h {

width = w;

height = h;

}

-(int) width {

return width;

}

-(int) height {

return height;

}

-(void) print {

printf( "width = %i, height = %i", width, height );

}

@end

//-----------Square

@implementation Square

-(Square*) initWithSize: (int) s {

self = [super init];

if ( self ) {

[self setSize: s];

}

return self;

}

-(void) setSize: (int) s {

width = s;

height = s;

}

-(int) size {

return width;

}

-(void) setWidth: (int) w {

[self setSize: w];

}

-(void) setHeight: (int) h {

[self setSize: h];

}

@end

------------------调用时的一个小问题---------

void RECT()

{

Rectangle *rec = [[Rectangle alloc] initWithWidth: 10 height: 20];

Square *sq = [[Square alloc] initWithSize:13 ];//------------Build 失败.....

//正确的写法如下:

/*-------不知道会不会造成泄露

Square *sq = [[Square alloc] init ];
[sq initWithSize:13];//----调用了2次?

*/

//或者如下

Square *sq = [(Square *)[Square alloc] initWithSize:13 ];

[sq setWidth: 20];

[sq print];

[rec release];

[sq release];

}