创建多个绘制的线条

Question

所以我需要绘制2条不同的线条.通过另一个帖子,我想出了如何重新绘制一条线.我的问题是,如果我想绘制2行,我需要有2个代码段来做吗？或者有没有办法绘制n行？

- (void)drawRect:(CGRect)rect
{
    CGContextRef context = UIGraphicsGetCurrentContext();
    NSLog(@"drawRect called");
    CGContextSetLineWidth(context, self.lineWidth);
    CGContextSetStrokeColorWithColor(context, self.lineColor.CGColor);
    CGContextMoveToPoint(context, self.startPoint.x, self.startPoint.y);
    CGContextAddLineToPoint(context, self.endPoint.x, self.endPoint.y);
    CGContextStrokePath(context);
} 

履行

draw2D *myCustomView = [[draw2D alloc] init];

myCustomView.startPoint = CGPointMake(0, 0);
myCustomView.endPoint = CGPointMake(300, 300);
myCustomView.lineWidth = 5;
myCustomView.lineColor = [UIColor redColor];

myCustomView.frame = CGRectMake(0, 0, 500, 500);
[myCustomView setBackgroundColor:[UIColor blueColor]];
[self.view addSubview:myCustomView];
[myCustomView setNeedsDisplay];

myCustomView.endPoint = CGPointMake(100, 100);

myCustomView.lineColor = [UIColor orangeColor];
[myCustomView setNeedsDisplay];

这只会重新划线.我会为我想要的每一行重复drawRect块吗？所以,如果我想要两条线,我必须这样做:

- (void)drawRect:(CGRect)rect
{
    //line1
    CGContextRef context1 = UIGraphicsGetCurrentContext();
    NSLog(@"drawRect called");
    CGContextSetLineWidth(context1, self.lineWidth1);
    CGContextSetStrokeColorWithColor(context1, self.lineColor1.CGColor);
    CGContextMoveToPoint(context1, self.startPoint1.x, self.startPoint1.y);
    CGContextAddLineToPoint(context1, self.endPoint1.x, self.endPoint1.y);
    CGContextStrokePath(context1);

    //line 2
    CGContextRef context2 = UIGraphicsGetCurrentContext();
    NSLog(@"drawRect called");
    CGContextSetLineWidth(context2, self.lineWidth2);
    CGContextSetStrokeColorWithColor(context2, self.lineColor2.CGColor);
    CGContextMoveToPoint(context2, self.startPoint2.x, self.startPoint2.y);
    CGContextAddLineToPoint(context2, self.endPoint2.x, self.endPoint2.y);
    CGContextStrokePath(context2);
} 

还是有更好的方法来处理我的线条？

编辑:最终目标是使用它UIView与标签和文本框我用作表格.我想要线条来分解表格.

我想知道我是否应该只使用这些自定义draw2D UIView作为行,并将它们放在UIView表单的顶部,然后我可以创建多个"draw2D" UIViews？

解:

所以这里是我认为可行的代码:

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code

        NSMutableArray *tempArray = [[NSMutableArray alloc] init];

        NSMutableDictionary *tempDict = [[NSMutableDictionary alloc] init];
        [tempDict setValue:[NSValue valueWithCGPoint:CGPointMake(10, 10)] forKey:@"start"];
        [tempDict setValue:[NSValue valueWithCGPoint:CGPointMake(500, 500)] forKey:@"end"];

        [tempArray addObject:tempDict];

        NSMutableDictionary *tempDict2 = [[NSMutableDictionary alloc] init];
        [tempDict2 setValue:[NSValue valueWithCGPoint:CGPointMake(400, 10)] forKey:@"start"];
        [tempDict2 setValue:[NSValue valueWithCGPoint:CGPointMake(500, 500)] forKey:@"end"];

        [tempArray addObject:tempDict2];

        self.pointArray = [NSArray arrayWithArray:tempArray];
    }
    return self;
}


// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetLineWidth(context, self.lineWidth);
    CGContextSetStrokeColorWithColor(context, self.lineColor.CGColor);

    for (int i = 0; i < [self.pointArray count]; i++)
    {
        CGPoint tempPoint = [[[self.pointArray objectAtIndex:i] objectForKey:@"start"] CGPointValue];
        CGPoint tempPoint2 = [[[self.pointArray objectAtIndex:i] objectForKey:@"end"] CGPointValue];

        CGContextMoveToPoint(context, tempPoint.x, tempPoint.y);
        CGContextAddLineToPoint(context, tempPoint2.x, tempPoint2.y);
    }

    CGContextStrokePath(context);
}

我在创建用于测试的数组时包含了我的initWithFrame:方法(CGPoint不是对象,因此必须弄清楚如何将它们包含在字典中).

所以这将循环并创建n行.

Answer 1

您可以根据需要重复此位(每次显示不同的坐标).

CGContextMoveToPoint(context, self.startPoint.x, self.startPoint.y);
CGContextAddLineToPoint(context, self.endPoint.x, self.endPoint.y);

第一行代码设置行的起始点,第二行代码绘制它.您无需重复所有其余代码.

换句话说,您可以像这样绘制多条线:

//set up context
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context, self.lineWidth1);
CGContextSetStrokeColorWithColor(context, self.lineColor1.CGColor);

//line1
CGContextMoveToPoint(context, self.startPoint1.x, self.startPoint1.y);
CGContextAddLineToPoint(context, self.endPoint1.x, self.endPoint1.y);

//line 2
CGContextMoveToPoint(context, self.startPoint2.x, self.startPoint2.y);
CGContextAddLineToPoint(context, self.endPoint2.x, self.endPoint2.y);

//line 3
etc...

//finished drawing
CGContextStrokePath(context);

每次绘制一条线时都不需要复制整批,你可以重复这两行代码.