如何覆盖uibutton子类中的-drawrect?

正如其他人所说,您不需要对uibutton进行子类划分——事实上,最好不要因为uibutton相当复杂(正如您发现的那样)。您有三种选择:

• 将按钮标题留空,并在所需位置向按钮添加新的文本字段。
• 如果使用3.0,请访问按钮的Label属性。虽然标签本身是只读的,但其属性(包括框架)不是只读的。
• uicontrol子类。uicontrol是一个uiview,因此您可以添加其他视图-文本和图像,而uiview实现了动作消息行为。( addTarget:action:forControlEvents: )uibutton在此基础上实现了状态性。

如果你不需要像uibutton那样的东西 setTitle:forState: 以及相关的功能,但是您使用了很多这些控件,我将使用第三个选项。否则使用第一个(如果您在3.0上,则使用第二个)。

这对我来说很好…(忽略复杂的绘图代码)。

1. 创建uibutton的子类
2. 在故事板中创建uibutton
3. 转到身份检查器并输入自定义的名称 按钮类

这里是我的ui按钮代码:

h文件:

#import <UIKit/UIKit.h>

@interface DoneButton : UIButton

@property (assign, nonatomic) BOOL selected;

@end

M文件:

 #import "DoneButton.h"

    @implementation DoneButton

    @synthesize selected = _selected;

    - (id)initWithFrame:(CGRect)frame
    {
        self = [super initWithFrame:frame];
        if (self) {
            // Initialization code
        }
        return self;
    }

    - (void)setSelected:(BOOL)selected
    {
        if (_selected != selected) {
            _selected = selected;
            [self setNeedsDisplay];
        }
    }


    - (void)drawRect:(CGRect)rect
    {
        // Drawing code

        if (_selected) {
            //// Color Declarations
            UIColor* color2 = [UIColor colorWithRed: 0 green: 0 blue: 0 alpha: 1];

            //// Bezier Drawing
            UIBezierPath* bezierPath = [UIBezierPath bezierPath];
            [bezierPath moveToPoint: CGPointMake(49.39, 31.25)];
            [bezierPath addLineToPoint: CGPointMake(49.39, 31.25)];
            [bezierPath addCurveToPoint: CGPointMake(46.64, 25.19) controlPoint1: CGPointMake(49.39, 29.02) controlPoint2: CGPointMake(48.38, 26.94)];
            [bezierPath addCurveToPoint: CGPointMake(44.3, 18.95) controlPoint1: CGPointMake(46.63, 22.72) controlPoint2: CGPointMake(45.88, 20.53)];
            [bezierPath addCurveToPoint: CGPointMake(42.44, 17.59) controlPoint1: CGPointMake(43.75, 18.4) controlPoint2: CGPointMake(43.13, 17.95)];
            [bezierPath addCurveToPoint: CGPointMake(38.07, 16.61) controlPoint1: CGPointMake(41.17, 16.93) controlPoint2: CGPointMake(39.67, 16.62)];
            [bezierPath addCurveToPoint: CGPointMake(33.15, 13.95) controlPoint1: CGPointMake(36.62, 15.18) controlPoint2: CGPointMake(34.95, 14.23)];
            [bezierPath addCurveToPoint: CGPointMake(32.78, 13.92) controlPoint1: CGPointMake(33.03, 13.93) controlPoint2: CGPointMake(32.9, 13.93)];
            [bezierPath addCurveToPoint: CGPointMake(32, 13.86) controlPoint1: CGPointMake(32.52, 13.89) controlPoint2: CGPointMake(32.26, 13.86)];
            [bezierPath addLineToPoint: CGPointMake(32, 13.86)];
            [bezierPath addLineToPoint: CGPointMake(32, 13.86)];
            [bezierPath addLineToPoint: CGPointMake(32, 13.86)];
            [bezierPath addLineToPoint: CGPointMake(32, 13.86)];
            [bezierPath addCurveToPoint: CGPointMake(31.38, 13.91) controlPoint1: CGPointMake(31.79, 13.86) controlPoint2: CGPointMake(31.59, 13.89)];
            [bezierPath addCurveToPoint: CGPointMake(30.85, 13.95) controlPoint1: CGPointMake(31.2, 13.92) controlPoint2: CGPointMake(31.02, 13.92)];
            [bezierPath addCurveToPoint: CGPointMake(26.92, 15.74) controlPoint1: CGPointMake(29.44, 14.17) controlPoint2: CGPointMake(28.12, 14.8)];
            [bezierPath addCurveToPoint: CGPointMake(25.94, 16.61) controlPoint1: CGPointMake(26.58, 16.01) controlPoint2: CGPointMake(26.25, 16.29)];
            [bezierPath addCurveToPoint: CGPointMake(24.13, 16.76) controlPoint1: CGPointMake(25.31, 16.61) controlPoint2: CGPointMake(24.71, 16.66)];
            [bezierPath addCurveToPoint: CGPointMake(19.7, 18.95) controlPoint1: CGPointMake(22.41, 17.06) controlPoint2: CGPointMake(20.88, 17.77)];
            [bezierPath addCurveToPoint: CGPointMake(17.36, 25.19) controlPoint1: CGPointMake(18.12, 20.53) controlPoint2: CGPointMake(17.37, 22.72)];
            [bezierPath addCurveToPoint: CGPointMake(14.61, 31.25) controlPoint1: CGPointMake(15.62, 26.94) controlPoint2: CGPointMake(14.61, 29.02)];
            [bezierPath addLineToPoint: CGPointMake(14.61, 31.25)];
            [bezierPath addCurveToPoint: CGPointMake(14.61, 31.25) controlPoint1: CGPointMake(14.61, 31.25) controlPoint2: CGPointMake(14.61, 31.25)];
            [bezierPath addCurveToPoint: CGPointMake(14.66, 31.92) controlPoint1: CGPointMake(14.61, 31.48) controlPoint2: CGPointMake(14.64, 31.7)];
            [bezierPath addCurveToPoint: CGPointMake(14.7, 32.4) controlPoint1: CGPointMake(14.67, 32.08) controlPoint2: CGPointMake(14.67, 32.24)];
            [bezierPath addCurveToPoint: CGPointMake(15.86, 35.44) controlPoint1: CGPointMake(14.86, 33.46) controlPoint2: CGPointMake(15.27, 34.48)];
            [bezierPath addCurveToPoint: CGPointMake(15.97, 35.64) controlPoint1: CGPointMake(15.9, 35.5) controlPoint2: CGPointMake(15.93, 35.57)];
            [bezierPath addCurveToPoint: CGPointMake(17.36, 37.32) controlPoint1: CGPointMake(16.36, 36.23) controlPoint2: CGPointMake(16.83, 36.78)];
            [bezierPath addCurveToPoint: CGPointMake(17.49, 38.98) controlPoint1: CGPointMake(17.36, 37.89) controlPoint2: CGPointMake(17.41, 38.44)];
            [bezierPath addCurveToPoint: CGPointMake(18.35, 41.7) controlPoint1: CGPointMake(17.65, 39.95) controlPoint2: CGPointMake(17.92, 40.87)];
            [bezierPath addCurveToPoint: CGPointMake(19.7, 43.55) controlPoint1: CGPointMake(18.7, 42.38) controlPoint2: CGPointMake(19.15, 43)];
            [bezierPath addCurveToPoint: CGPointMake(25.93, 45.89) controlPoint1: CGPointMake(21.28, 45.13) controlPoint2: CGPointMake(23.47, 45.88)];
            [bezierPath addCurveToPoint: CGPointMake(27.61, 47.28) controlPoint1: CGPointMake(26.47, 46.42) controlPoint2: CGPointMake(27.02, 46.89)];
            [bezierPath addCurveToPoint: CGPointMake(32, 48.64) controlPoint1: CGPointMake(28.96, 48.16) controlPoint2: CGPointMake(30.44, 48.64)];
            [bezierPath addLineToPoint: CGPointMake(32, 48.64)];
            [bezierPath addLineToPoint: CGPointMake(32, 48.64)];
            [bezierPath addLineToPoint: CGPointMake(32, 48.64)];
            [bezierPath addLineToPoint: CGPointMake(32, 48.64)];
            [bezierPath addCurveToPoint: CGPointMake(38.06, 45.89) controlPoint1: CGPointMake(34.23, 48.64) controlPoint2: CGPointMake(36.31, 47.63)];
            [bezierPath addCurveToPoint: CGPointMake(44.3, 43.55) controlPoint1: CGPointMake(40.53, 45.88) controlPoint2: CGPointMake(42.72, 45.13)];
            [bezierPath addLineToPoint: CGPointMake(44.3, 43.55)];
            [bezierPath addLineToPoint: CGPointMake(44.3, 43.55)];
            [bezierPath addCurveToPoint: CGPointMake(46.64, 37.31) controlPoint1: CGPointMake(45.88, 41.97) controlPoint2: CGPointMake(46.63, 39.78)];
            [bezierPath addCurveToPoint: CGPointMake(49.39, 31.25) controlPoint1: CGPointMake(48.38, 35.56) controlPoint2: CGPointMake(49.39, 33.48)];
            [bezierPath addLineToPoint: CGPointMake(49.39, 31.25)];
            [bezierPath closePath];
            [color2 setStroke];
            bezierPath.lineWidth = 1;
            [bezierPath stroke];


            //// Bezier 2 Drawing
            UIBezierPath* bezier2Path = [UIBezierPath bezierPath];
            [bezier2Path moveToPoint: CGPointMake(22.42, 29.85)];
            [bezier2Path addLineToPoint: CGPointMake(29.74, 37.17)];
            [bezier2Path addLineToPoint: CGPointMake(41.58, 25.33)];
            bezier2Path.usesEvenOddFillRule = YES;

            [color2 setStroke];
            bezier2Path.lineWidth = 1;
            [bezier2Path stroke];

        } else {

            //// Color Declarations
            UIColor* color3 = [UIColor colorWithRed: 0.5 green: 0.5 blue: 0.5 alpha: 1];

            //// Bezier 2 Drawing
            UIBezierPath* bezier2Path = [UIBezierPath bezierPath];
            [bezier2Path moveToPoint: CGPointMake(22.42, 29.85)];
            [bezier2Path addLineToPoint: CGPointMake(29.74, 37.17)];
            [bezier2Path addLineToPoint: CGPointMake(41.58, 25.33)];
            bezier2Path.usesEvenOddFillRule = YES;

            [color3 setStroke];
            bezier2Path.lineWidth = 1;
            [bezier2Path stroke];
        }
    }

如果选择按钮,则绘制第一个代码,否则绘制另一个代码。 我喜欢这个方法,因为我使用了油漆代码。这样可以节省很多时间,而且您不需要创建数千个PNG或JPEG。

根据您对其他答案之一的评论,这是一个询问“如何用x和y实现z”的案例。当你真的应该问“我怎样才能得到z?”

如果您希望按钮在图像上而不是旁边绘制文本,只需将图像设置为按钮的背景图像即可。使用 setBackgroundImage:forState: 而不是 setImage:forState: ,然后正常设置标题。

在任何情况下,你要么要画图像 drawRect: 或者将文本移动到子视图中,以便在图像上方绘制。我提到的解决方案是第二个选项的版本。

您不需要子类uibutton,只需添加一些文本即可。以下是在uiviewcontroller子类的-viewdidload方法中为自定义按钮设置按钮标题的示例:

UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(0, 0, 44, 44);
[button setTitle:@"x" forState:UIControlStateNormal];
[self.view addSubview:button];

您还可以设置按钮的字体属性或使用-settitlecolor:forstate:更改颜色。

在按钮的视图上添加子视图怎么样?然后你就可以完全控制它,而不在乎按钮做了什么。你甚至可以把它做成一个标签,把它保存下来。