学步园

按照网上的方法安装环境，在csdn下载相应软件很快搞定，写了测试程序如下：

分开一个一个文件写编译不了，应该是要写连接编译参数等的东西，不懂！所以写在同一个文件是最简单的，文件命名为helloworld.m

编译命令：gcc -o NilTest NilTest.m -I/GNUstep/System/Library/Headers -fconstant-string-class=NSConstantString -L/GNUstep/System/Library/Libraries -lobjc -lgnustep-base

环境按这篇文章搭建：

http://blog.csdn.net/zajin/article/details/9133793

#import <Foundation/Foundation.h> 

@interface XYPoint:NSObject{
	int x;
	int y;
}

-(id)initWithX:(int) _x andY:(int) _y;
-(void) dealloc;
@end

@implementation XYPoint

-(id)initWithX:(int) _x andY:(int)_y{
	x = _x;
	y = _y;
}

-(void) dealloc { 
	NSLog(@"Point is dealloc!"); 
	return [super dealloc];
}


@end

@interface Circle:NSObject{
	int r;
	XYPoint* p;
}

-(void)print;
-(void)setP:(int) _x :(int) _y;
-(XYPoint*)getP;

@end

@implementation Circle

-(void) print{
	NSLog(@"radius is : %d point is : %@  isa is : %@",r,p,isa);
	NSLog(@"point retaincount is : %d",[p retainCount]);
}

-(void) setP:(int) _x :(int) _y{
	[p release];
	p = [[XYPoint alloc] initWithX:_x andY:_y];
}

-(XYPoint*) getP{
	return p;
}

@end

int main (int argc, const char*argv[]) 
{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
NSLog(@"Hello World!");

Circle* c = [[Circle alloc] init];
[c setP:10 :20];

//[[c getP] release];//看看是否会调用Point的dealloc，会调用dealloc方法
//[[c getP] retainCount];//windows环境下报内存不能为read，因为p已经释放
//[[c getP] release];//连续两次release，报内存不能为read，因为p已经释放，释放后就是销毁了，不是Nil空值。
[c print];
[pool drain];

return 0;
}