Question

我想创建一个类似于UIBackBarButtonItem的UIButton（向左指向导航堆栈的箭头。我更愿意这样做而不必使用图像，如果可能的话，因为按钮将具有不同的大小，具体取决于在电话的方向。

有没有办法在代码中激活这种影响？我的想法是以某种方式使用按钮的CALayer。

谢谢！

修改

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[UIBezierPath bezierPathWithRoundedRect：rect cornerRadius：4]，左侧看起来像箭头。我尝试使用addQuadCurveToPoint：controlPoint方法执行此操作。

我使用rect的一角作为控制点，但路径不像我期望的那样弯曲。它仍然是走投无路的，好像我只使用了addLineToPoint：方法。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

您可以使用Quartz执行此操作。您将需要子类UIButton并实现其drawRect:方法。您必须定义路径并使用渐变填充它。

您还必须实施hitTest:withEvent:，因为它涉及非矩形形状。

Answer 2

这解决了我的绘图难题

    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];

自定义UIButton Shape而不使用图像

2 个答案: