Custom UIButton Shape without using an image

问题:

I want to make a UIButton with that looks similar to the UIBackBarButtonItem (with an arrow pointing left for the navigation stack. I would prefer to do this without having to use an image if possible because the button will have a different size depending on the phone's orientation.

Is there a way to active this affect in code? My idea was using the CALayer of the button somehow.

Thanks!

EDIT

I am trying to use @Deepak's advice, but I am running into a a problem. I want the right side of the button to look like a [UIBezierPath bezierPathWithRoundedRect:rect cornerRadius:4] with the left side looking like an arrow. I tried to do this using the addQuadCurveToPoint:controlPoint method.

I am using the corner of the rect as the control point, but the path does not curve like I expect. It is still cornered as if I only used the addLineToPoint: method. My code is below.

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];

回答1:

You can do this with Quartz. You will need subclass UIButton and implement its drawRect: method. You will have to define a path and fill it with a gradient.

You will also have to implement hitTest:withEvent: as it involves non-rectangular shape.

回答2:

This solved the drawing difficulties for me

    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];