//一定要重写UIView类中的-(void)drawRect:(CGRect)rect方法才能画线；


//绘制UIView

-(void)drawRect:(CGRect)rect

{

[self drawLine];

}


/**

* 画线

*/

-(void)drawLine

{

//1.获取上下文

CGContextRef context = UIGraphicsGetCurrentContext();

//2.创建可变的路径并设置路径

CGMutablePathRef path = CGPathCreateMutable();

//1）设置起始点

CGPathMoveToPoint(path, NULL, 65, 215);

//2）设置目标点

CGPathAddLineToPoint(path, NULL, 115, 220);

//3.将路径添加到上下文

CGContextAddPath(context, path);

//4.设置上下文属性

/**

kCGPathStroke: 画线 (空心）

kCGPathFill: 填充 (实心)

kCGPathFillStroke: 即画线又填充

*/

CGContextDrawPath(context, kCGPathFillStroke);

//5.绘制路径

CGContextDrawPath(context, kCGPathFillStroke);

//6.释放 路径

CGPathRelease(path);

}