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我正在尝试实现切换按钮的自定义实现，以便一次只能选择一个。我遇到了一个奇怪的错误，我使用[[ajdSwitchButton alloc] init]. 在初始化中，我设置了一个类属性，如下所示self.currentSelection = 2。

问题是在init第一次调用和第一次调用IBAction方法之间，值更改为 0。我不知道为什么。以下是相关代码：

ajdSwitchButton.h

#import <UIKit/UIKit.h>

@interface ajdSwitchButton : UIView

@property (nonatomic) NSInteger currentSelection;

// Button Outlets
@property (nonatomic, strong) IBOutlet UIButton *buttonOne;
@property (nonatomic, strong) IBOutlet UIButton *buttonTwo;

// Button Actions
- (IBAction)buttonPress:(id)sender;
- (IBAction)buttonPressTwo:(id)sender;

// Instance Methods
- (void)switchButtonState:(UIButton *)button;

@end

ajdSwitchButton.m

#import "ajdSwitchButton.h"

@implementation ajdSwitchButton

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        _currentSelection = 2;
    }
    return self;
}

// Handles button press actions for buttonOne
- (IBAction)buttonPress:(id)sender {
    NSLog(@"%@", self);
    // Y button pressed
    if (self.currentSelection == 2) {
        // No button is selected
        // Highlight and select buttonOne
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonOne afterDelay:0.0];
    } else if (self.currentSelection == 1) {
        // No was previously selected
        // Unselect NO and select YES
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonTwo afterDelay:0.0];
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonOne afterDelay:0.0];
    } else {
    // Y button already pressed
    [self performSelector:@selector(switchButtonState:) withObject:self.buttonOne afterDelay:0.0];
    }
    self.currentSelection = 0;
}

- (IBAction)buttonPressTwo:(id)sender {
    // N button pressed
    NSLog(@"%i", self.currentSelection);
    if (self.currentSelection == 2) {
        // No button is selected
        // Highlight and select buttonOne
    [self performSelector:@selector(switchButtonState:) withObject:self.buttonTwo afterDelay:0.0];
} else if (self.currentSelection == 0) {
        // Yes was previously selected
        // Unselect YES and select NO
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonTwo afterDelay:0.0];
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonOne afterDelay:0.0];
    } else {
        // N button already pressed
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonTwo afterDelay:0.0];
    }
    self.currentSelection = 1;
}

// Switches the look and state of the button
- (void)switchButtonState:(UIButton *)button {
    if (!button.selected) {
        button.highlighted = YES;
        button.selected = YES;
    } else {
        button.highlighted = NO;
        button.selected = NO;
    }
}
@end

我将的实例链接ajdSwitchButton到. 任何帮助将不胜感激。IBOutletViewController

init编辑：我粘贴了一些 NSLogs 以在调用该IBAction方法后直接检查对象的内存值。这是之前和之后：

<ajdSwitchButton: 0x746d2e0; frame = (0 0; 0 0); layer = <CALayer: 0x7472c40>>

<ajdSwitchButton: 0x7471b10; frame = (77 232; 180 83); autoresize = TM+BM; layer = <CALayer: 0x7471bf0>>

4

3 回答 3

0

IBOutlets 通过initWithCoder:(NSCoder)aDecoder init，所以需要实现这个方法。

- (id)initWithCoder:(NSCoder *)aDecoder
{
    self = [super initWithCoder:aDecoder];
    if (self) {
        // Initialization code
        _currentSelection = 2;
    }
    return self;
}
于 2013-01-15T07:07:26.487 回答
0

您正在代码中执行此操作...

这可能是一个愚蠢的错误，或者您需要它..请检查您的代码：

- (IBAction)buttonPress:(id)sender {
    NSLog(@"%@", self);
    // Y button pressed
    if (self.currentSelection == 2) {
        // No button is selected
        // Highlight and select buttonOne
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonOne afterDelay:0.0];
    } else if (self.currentSelection == 1) {
        // No was previously selected
        // Unselect NO and select YES
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonTwo afterDelay:0.0];
        [self performSelector:@selector(switchButtonState:) withObject:self.buttonOne afterDelay:0.0];
    } else {
    // Y button already pressed
    [self performSelector:@selector(switchButtonState:) withObject:self.buttonOne afterDelay:0.0];
    }



    /*  SEE HERE */

    self.currentSelection = 0;
}
于 2013-01-15T06:50:57.770 回答
0

问题在于你的问题本身。

您正在初始化变量：

- (id)initWithFrame:(CGRect)frame
{
}

您已经提到您正在使用创建对象[[ajdSwitchButton alloc] init]。

您init不是在调用initWithFrame，因此变量永远不会被初始化。所以实现一个函数，如：

- (id)init
{
    self = [super init];
    if (self) {
        // Initialization code
        _currentSelection = 2;
    }
    return self;
}
于 2013-01-15T08:03:30.840 回答