如何在iphone的视图中的两个分接点之间绘制自动线 [英] how to draw automatic line between two tap points in a view in iphone
问题描述
如何在用户点击两个不同的点后自动绘制一条线。该行应该加入这两个不同的点。
How can we draw a line automatically after the user taps two different points. The line should be joining those two different points.
应该使用哪些框架和方法。
What frameworks and methods should be used do so.
谢谢
推荐答案
您可以将触摸的位置存储在两个不同的 CGPoint
中被触及的
方法的帮助(文档)。
You can store the touched locations in two different CGPoint
with the help of the touchedEnded
method (documentation).
然后,当你得到两分时,你可以添加一个新的UIView作为子视图,它知道两个 CGPoint
,并将在其 drawRect
中绘制一条线方法。或者在当前视图中执行此操作,方法是调用 [view setNeedsDisplay]
来触发自己的 drawRect
方法。
Then, when you have your two points, you can add a new UIView as subview which is aware of the two CGPoint
and will draw a line in its drawRect
method. Or do it in the current view, by calling [view setNeedsDisplay]
to trigger its own drawRect
method.
如果您不知道如何使用CoreGraphics绘制一条简单的行,这就是开头:
If you don't know how to draw a simple line with CoreGraphics, here is the beginning :
- (void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
CGContextSetStrokeColorWithColor(context, [[UIColor blackColor]CGColor]);
CGContextSetLineWidth(context, 1.0);
CGContextMoveToPoint(context, startPoint.x, startPoint.y);
CGContextAddLineToPoint(context, endPoint.x, endPoint.y);
CGContextStrokePath(context);
CGContextRestoreGState(context);
}
这篇关于如何在iphone的视图中的两个分接点之间绘制自动线的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!