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我为 UIButton 类做了扩展。现在，如果我使用它，一切都会很好。但是我有另一个类为我创建带有 UIButton 对象的数组，在这里我遇到了一些问题。

我有 Helper 类，其方法为我返回带有 UIButton 对象的数组。

在 viewDidLoad 回调中的 ViewController.m 中，我请求了这个数组，并且在 ViewController.m 中，我导入了我的 UIButton+Extension.m

所以，现在我有每个 UIButton 对象的扩展，我将在 ViewController.m 中使用

但是，如果我使用扩展名，我会在调用的方法上遇到错误

[thumbButton.titleLabel setFont:[UIFont fontWithName:@"Helvetica" size:11.0]];

但是如果我不使用扩展这个方法调用正确。

这是我的 UIButton+Extension.h 文件

#import <UIKit/UIKit.h>

@interface UIButton (extension_button)

- (void)centerButtonToView:(UIView *)view;
- (UIImage *)cropeImage:(UIImageView *)imageView;

@end

这是我的 UIButton+Extension.m 文件

#import "UIButton+Extension.h"

@implementation UIButton (extension_button)

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

- (void)centerButtonToView:(UIView *)view {
    CGRect rect = view.frame;
    CGRect rectSelf = self.frame;
    rectSelf.origin.x = (rect.size.width / 2.0f - rectSelf.size.width / 2.0f) + rect.origin.x;
    rectSelf.origin.y = (rect.size.height / 2.0f - rectSelf.size.height / 2.0f) + rect.origin.y;
    self.frame = rectSelf;
}

- (UIImage *)cropeImage:(UIImageView *)imageView {    
    CGRect rect;
    rect.origin.x = self.frame.origin.x - imageView.frame.origin.x;
    rect.origin.y = self.frame.origin.y - imageView.frame.origin.y;
    rect.size.width = self.frame.size.width;
    rect.size.height = self.frame.size.height;    
    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();    
    CGRect drawRect = CGRectMake(-rect.origin.x,-rect.origin.y, imageView.image.size.width, imageView.image.size.height);
    CGContextClipToRect(context, CGRectMake(0, 0, rect.size.width, rect.size.height));
    [imageView.image drawInRect:drawRect];
    UIImage* subImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return subImage; 
}

@end

Helper.m（为我返回数组的方法，这里我在 setFont 方法上有问题）

+ (NSMutableArray *)createThumbnailsForCropSize {

    CGFloat width = 0.0f;
    CGFloat start_pos = 0.0f;

    if (IS_IPHONE) {
        width = 320.0f;
        start_pos = 62.0f;
    }
    else {
        width = 768.0f;
        start_pos = 286.0f;
    }

    NSMutableArray *arr = [[NSMutableArray alloc] init];
    NSArray *resolutionArray = [NSArray arrayWithObjects:@"30x40",@"33x48",@"35x40",@"35x45",@"36x47",@"37x47",
                                @"40x50",@"40x60",@"43x55",@"45x50",@"50x50",@"50x70", nil];
    NSInteger pos_x = start_pos;
    NSInteger page = 0;
    for (NSInteger idx = 0; idx < 12; idx++) {
        if (idx%3 == 0 && idx != 0) {
            page++;
            pos_x = start_pos + width * page;
        }
        UIButton *thumbButton = [[UIButton alloc] init];
        [thumbButton setTag:idx];
        [thumbButton setFrame:CGRectMake(pos_x, 13, 60, 60)];
        [thumbButton setTitle:[NSString stringWithFormat:[resolutionArray objectAtIndex:idx]] forState:UIControlStateNormal];
        [thumbButton.titleLabel setFont:[UIFont fontWithName:@"Helvetica" size:11.0]];
        [thumbButton setTitle:@"!00" forState:UIControlStateNormal];
        [thumbButton setBackgroundImage:[UIImage imageNamed:@"block_without_photo.png"] forState:UIControlStateNormal];
        [arr addObject:thumbButton];
        pos_x += 68;
    }
    return arr;
}
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1 回答 1

2

您需要initWithFrame:从您的类别中删除。通过包含它，您将删除正常的实现，这将阻止您的按钮被正确创建，实际上您将返回一个UIControl.

调用super类别中的实现不会调用的实现，而是调用-UIButton的超类。类别不同于子类。（而且你也不应该子类化，因为它是一个类集群）。UIButtonUIControlUIButton

如果您确实有专门的初始化代码，则必须将其添加到单独的方法中并在创建循环期间调用它。

于 2012-07-25T10:10:58.083 回答