不使用图像的自定义UIButton形状

Question

我想创建一个与UIBackBarButtonItem类似的UIButton（带有箭头指向左侧的导航堆栈，如果可能的话，我宁愿这样做而不必使用图像，因为按钮会根据手机的方向有不同的尺寸。

有没有办法来活跃在这个代码影响？我的想法是使用按钮的CALayer不知何故。

谢谢！

编辑

我正在尝试使用@ Deepak的建议，但我遇到了一个问题。我希望按钮的右侧看起来像一个[UIBezierPath bezierPathWithRoundedRect：rect cornerRadius：4]，左侧看起来像一个箭头。我试图用addQuadCurveToPoint：controlPoint方法来做到这一点。

我正在使用矩形的拐角作为控制点，但路径不像我期望的那样弯曲。它仍然像我只使用addLineToPoint：方法一样受到限制。我的代码如下。

float radius = 4.0; 
UIBezierPath *path = [UIBezierPath bezierPath]; 

CGPoint startPoint = CGPointMake(rect.size.width/5.0, 0); 
CGPoint pointBeforeTopCurve = CGPointMake(rect.size.width - radius, 0); 
CGPoint topRightCorner = CGPointMake(rect.size.width, 0); 
CGPoint pointAfterTopCurve = CGPointMake(rect.size.width, 0.0-radius); 

CGPoint pointBeforeBottomCurve = CGPointMake(rect.size.width, rect.size.height-radius); 
CGPoint bottomRightCorner = CGPointMake(rect.size.width, rect.size.height); 
CGPoint pointAfterBottomCurve = CGPointMake(rect.size.width - radius, rect.size.height); 

CGPoint pointBeforeArrow = CGPointMake(rect.size.width/5.0, rect.size.height); 
CGPoint arrowPoint = CGPointMake(0, rect.size.height/2.0); 


[path moveToPoint:pointBeforeTopCurve]; 
[path addQuadCurveToPoint:pointAfterTopCurve controlPoint:topRightCorner]; 

[path addLineToPoint:pointBeforeBottomCurve]; 
[path addQuadCurveToPoint:pointAfterBottomCurve controlPoint:bottomRightCorner]; 


[path addLineToPoint:pointBeforeArrow]; 
[path addLineToPoint:arrowPoint]; 
[path addLineToPoint:startPoint]; 

Answer 1

您可以用Quartz来做到这一点。您需要子类UIButton并实施其drawRect:方法。你将不得不定义一个路径并用渐变填充它。

您还必须实施hitTest:withEvent:，因为它涉及非矩形形状。

Answer 2

这解决了绘图的困难，我

float radius = 10.0; 
UIBezierPath *path = [UIBezierPath bezierPath]; 

CGPoint startPoint = CGPointMake(rect.size.width/5.0, 0); 
CGPoint pointBeforeTopCurve = CGPointMake(rect.size.width - radius, 0); 
CGPoint topRightCorner = CGPointMake(rect.size.width, 0.0); 
CGPoint pointAfterTopCurve = CGPointMake(rect.size.width, radius); 

CGPoint pointBeforeBottomCurve = CGPointMake(rect.size.width, rect.size.height-radius); 
CGPoint bottomRightCorner = CGPointMake(rect.size.width, rect.size.height); 
CGPoint pointAfterBottomCurve = CGPointMake(rect.size.width - radius, rect.size.height); 

CGPoint pointBeforeArrow = CGPointMake(rect.size.width/5.0, rect.size.height); 
CGPoint arrowPoint = CGPointMake(0.0, rect.size.height/2.0); 


[path moveToPoint:pointBeforeTopCurve]; 
[path addQuadCurveToPoint:pointAfterTopCurve controlPoint:topRightCorner]; 

[path addLineToPoint:pointBeforeBottomCurve]; 
[path addQuadCurveToPoint:pointAfterBottomCurve controlPoint:bottomRightCorner]; 


[path addLineToPoint:pointBeforeArrow]; 
[path addLineToPoint:arrowPoint]; 
[path addLineToPoint:startPoint]; 


[path fill];