Question

我试图在iOS上绘制和编辑多条线。每行的每一端都有一个UIView充当句柄，因此，一旦绘制了该行，用户就可以拖动每端并重新绘制该行。

我目前正在使用UIBezierPath在视图上绘制CAShapelayer。我遇到的问题是最好的方式来绘制另一条线，并且用户点击了哪条线都可以对其进行编辑。

有人对最佳方法有任何想法吗？ CAShapelayer是最好的选择吗？

视频链接可能会更好地显示我要实现的目标。

https://www.dropbox.com/s/8rpt2azrs3uk6vr/Line%20Example.mov?dl=0

我到目前为止已完成的代码示例如下：

//画一条线在这里，我从两个接触点创建路径，并在视图上绘制CAShapeLayer。我还创建了一个自定义对象“线”来存储路径和shapelayer。

-(void)DrawLineFrom:(CGPoint)pointA to:(CGPoint)pointB
{
    NSLog(@"Drawing line X:%f Y:%f - X:%f Y:%f", pointA.x, pointA.y, pointB.x, pointB.y);

    UIBezierPath* path = [[UIBezierPath alloc]init];
    [path moveToPoint:pointA];
    [path addLineToPoint:pointB];
    [path addLineToPoint:CGPointMake(pointB.x, pointB.y+2)];
    [path addLineToPoint:CGPointMake(pointA.x, pointA.y+2)];
    [path addLineToPoint:pointA];
    [path closePath];
    currentLine.bPath = path;

    if (!shapeLayer)
    {
        shapeLayer = [LineLayer layer];
        [shapeLayer setFrame:self.view.frame];
        shapeLayer.path = path.CGPath;
        shapeLayer.strokeColor = [UIColor redColor].CGColor; //etc...
        shapeLayer.lineWidth = 2.0; //etc...
        shapeLayer.parent = currentLine;
        currentLine.shapeLayer = shapeLayer;

        [self.view.layer addSublayer:shapeLayer];
    }
    else
    {
        shapeLayer.path = path.CGPath;
    }

    [self ExitDrawMode];

}

//创建一个句柄这将在两端创建两个视图，并添加长按手势。

-(HandleView *)MakeLineHandleForPoint:(int)point atLocation:(CGPoint)loc
{
    HandleView *pointView = [[HandleView alloc]initWithFrame:CGRectMake(loc.x-10, loc.y-10, 20, 20)];
    pointView.layer.cornerRadius = 10;
    pointView.backgroundColor = [UIColor redColor];
    UILongPressGestureRecognizer *LP = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLp:)];
    [pointView addGestureRecognizer:LP];
    LP.delegate = self;
    LP.minimumPressDuration = 0.0;
    pointView.userInteractionEnabled = YES;
    pointView.tag = point;
    pointView.lineParent = currentLine;

    return pointView;
}

最后，在此处处理手势。这可以正常工作，但是将始终移动最后绘制的线条。即使我选择了第一个。

-（void）handleLp：（UILongPressGestureRecognizer *）发送者 { CGPoint loc = [发件人locationInView：self.view];

[sender view].center = loc;
HandleView *handleView = [sender view];

if ([sender view].tag == 0) {
    currentLine.pointA = loc;
    [self DrawLineFrom:loc to:currentLine.pointB];
}
if ([sender view].tag == 1) {
    currentLine.pointB = loc;
    [self DrawLineFrom:currentLine.pointA to:loc];
}

}

非常感谢任何帮助。提前致谢。

在iOS中绘制/编辑线条

0 个答案: