Question

我制作程序，它将找到两个矩形交叉的区域。我有这个矩形的高度，宽度和坐标。

但它不会工作！ Xcode在此行（Rectangle.m）上使用“Thread 1：SIGNAL SIGABRT”终止程序：

reswidth = (origin.x + width) - (second.origin.x + second.width);

所以，这是我的代码：

main.m：

#import <Foundation/Foundation.h>
#import "Rectangle.h"
#import "XYPoint.h"

int main(int argc, const char * argv[])
{

    NSAutoreleasePool * pool = [NSAutoreleasePool new];
    Rectangle *myrect1 = [Rectangle new];
    Rectangle *myrect2 = [Rectangle new];
    XYPoint *temp = [XYPoint new];

    [temp setX: 200 andY: 420];
    [myrect1 setOrigin:temp];
   [temp setX: 400 andY: 300];
   [myrect2 setOrigin:temp];
   [temp dealloc];

   [myrect1 setWidth:250 andHeight:75];
   [myrect2 setWidth:100 andHeight:180];

   double print = [myrect1 intersect:myrect2];

   NSLog(@"%g", print);

   [pool drain];

   return 0;

}

Rectangle.h：

#import <Foundation/Foundation.h>
#import "XYPoint.h"

@interface Rectangle : NSObject
{
double width;
double height;
XYPoint *origin;
}

@property double width, height;

-(XYPoint *) origin;
-(void) setOrigin: (XYPoint *) pt;
-(void) setWidth: (double) w andHeight: (double) h;
-(double) area;
-(double) perimeter;
-(double) intersect: (Rectangle *) second;

@end

Rectangle.m：

#import "Rectangle.h"

@implementation Rectangle

@synthesize width, height;

-(void) setOrigin:(XYPoint *)pt
{
    origin = [[XYPoint alloc] init];
    [origin setX: pt.x andY: pt.y];
}

-(void) setWidth: (double) w andHeight: (double) h
{
    width = w;
    height = h;
}

-(double) area
{
    return width * height;
}

-(double) perimeter
{
    return (width + height) * 2;
}

-(double) intersect:(Rectangle *) second
{
    double result,reswidth,resheight;
    reswidth = (origin.x + width) - (second.origin.x + second.width);
    if (reswidth<0) reswidth *= -1;
    resheight = (origin.y + height) - (second.origin.y + second.height);
    if (resheight<0) resheight *= -1;
    result = reswidth * resheight;
    if (result<0) result *= -1;
    return result;
}
@end

XYPoint.h：

#import <Foundation/Foundation.h>

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

@property double x,y;

-(void) setX:(double) xVal andY: (double) yVal;

@end

XYPoint.m：

#import "XYPoint.h"

@implementation XYPoint

@synthesize x,y;

-(void) setX:(double) xVal andY: (double) yVal
{
    x=xVal;
    y=yVal;
}

@end

感谢!!!!

Answer 1

您没有在矩形类中实现方法-(XYPoint*) origin，因此在执行second.origin时会崩溃。只需将origin设置为矩形类中的属性即可。也不要过多使用新方法，这是不好的做法，并阻止你看到可能实现的其他init方法

找到两个矩形交叉区域时出错（objective-c）

1 个答案: