iOS应用程序中的复选框

Question

我需要在表单中添加复选框控件.我知道iOS SDK中没有这样的控件.我怎么能这样做？

Answer 1

这也让我很生气,我找到了一个适合我的不同解决方案,避免了使用图像.

1. 向Interface Builder添加新标签对象.
2. 在Xcode中创建一个IBOutlet属性并将其连接到它.在下面的代码中,我称之为'fullPaid',因为我想知道是否有人已经全额支付了一笔钱.
3. 添加以下2个功能.'touchesBegan'函数检查你是否触摸了'fully Paid'标签对象内的某个地方,如果是这样,它会调用'togglePaidStatus'函数.'togglePaidStatus'函数设置两个字符串,其中unicode字符分别表示空框(\ u2610)和复选框(\ u2611).然后它比较'fullPaid'对象中当前的内容并将其与另一个字符串切换.

您可能希望在viewDidLoad函数中调用togglePaidStatus函数,以便最初将其设置为空字符串.

显然,如果标签未启用,您可以添加额外的检查以防止用户切换复选框,但下面未显示.

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];   
    if (CGRectContainsPoint([fullyPaid frame], [touch locationInView:self.view]))
    {
        [self togglePaidStatus];
    }
}
-(void) togglePaidStatus
{
    NSString *untickedBoxStr = [[NSString alloc] initWithString:@"\u2610"];
    NSString *tickedBoxStr = [[NSString alloc] initWithString:@"\u2611"];   

    if ([fullyPaid.text isEqualToString:tickedBoxStr])
    {
        fullyPaid.text = untickedBoxStr;
    }
    else
    {
        fullyPaid.text = tickedBoxStr;
    }

    [tickedBoxStr release];
    [untickedBoxStr release];
}

Answer 2

通常,您可以将UISwitch用于类似复选框的功能.

您可以通过使用带有两个图像(已选中/未选中)的图像控件并在触摸控件时切换图像来自行滚动/

Answer 3

如果您正在显示一组选项,并且用户可以选择其中一个选项,请使用带有复选标记附件的表格视图以及所选行上的不同文本颜色.

如果您有一个选项,最好的办法是使用开关.如果您不能或不想,请使用按钮,将普通图像设置为空框,将所选图像设置为复选框.您必须自己制作这两张图片,或者找到可供他们使用的库存图片.

Answer 4

延伸到Adrean的想法,我使用一种非常简单的方法实现了这一目标.
我的想法是根据状态更改按钮(比如说checkBtn)文本,然后更改按钮的状态IBAction.
以下是我这样做的代码:

- (void)viewDidLoad
{
    [super viewDidLoad];

    [checkBtn setTitle:@"\u2610" forState:UIControlStateNormal];    // uncheck the button in normal state
    [checkBtn setTitle:@"\u2611" forState:UIControlStateSelected];  // check the button in selected state
}

- (IBAction)checkButtonTapped:(UIButton*)sender {
    sender.selected = !sender.selected;    // toggle button's selected state  

    if (sender.state == UIControlStateSelected) {    
        // do something when button is checked 
    } else {
        // do something when button is unchecked
    }
}

Answer 5

我想以编程方式执行此操作,并且还解决了命中区域实际上太小的问题.这可以从各种来源改编,包括Mike和Mike的评论员Agha.

在你的标题中

@interface YourViewController : UIViewController {
    BOOL checkboxSelected;
    UIButton *checkboxButton;
}

@property BOOL checkboxSelected;;
@property (nonatomic, retain) UIButton *checkboxButton;

-(void)toggleButton:(id)sender;

并在您的实施中

// put this in your viewDidLoad method. if you put it somewhere else, you'll probably have to change the self.view to something else
// create the checkbox. the width and height are larger than actual image, because we are creating the hit area which also covers the label
UIButton* checkBox = [[UIButton alloc] initWithFrame:CGRectMake(100, 60,120, 44)];  
[checkBox setImage:[UIImage imageNamed:@"checkbox.png"] forState:UIControlStateNormal];
// uncomment below to see the hit area
// [checkBox setBackgroundColor:[UIColor redColor]];
[checkBox addTarget:self action:@selector(toggleButton:) forControlEvents: UIControlEventTouchUpInside];
// make the button's image flush left, and then push the image 20px left
[checkBox setContentHorizontalAlignment:UIControlContentHorizontalAlignmentLeft];
[checkBox setImageEdgeInsets:UIEdgeInsetsMake(0.0, 20.0, 0.0, 0.0)];
[self.view addSubview:checkBox];

// add checkbox text text
UILabel *checkBoxLabel = [[UILabel alloc] initWithFrame:CGRectMake(140, 74,200, 16)];
[checkBoxLabel setFont:[UIFont boldSystemFontOfSize:14]];
[checkBoxLabel setTextColor:[UIColor whiteColor]];
[checkBoxLabel setBackgroundColor:[UIColor clearColor]];
[checkBoxLabel setText:@"Checkbox"];
[self.view addSubview:checkBox];

// release the buttons
[checkBox release];
[checkBoxLabel release];

并且也使用这种方法:

- (void)toggleButton: (id) sender
{
    checkboxSelected = !checkboxSelected;
    UIButton* check = (UIButton*) sender;
    if (checkboxSelected == NO)
        [check setImage:[UIImage imageNamed:@"checkbox.png"] forState:UIControlStateNormal];
    else
        [check setImage:[UIImage imageNamed:@"checkbox-checked.png"] forState:UIControlStateNormal];

}

Answer 6

这是我的iphone复选框版本.

它是单一类,扩展了UIButton.这很简单所以我会把它贴在这里.

CheckBoxButton.h文件内容

#import <UIKit/UIKit.h>

@interface CheckBoxButton : UIButton

@property(nonatomic,assign)IBInspectable BOOL isChecked;

@end

CheckBoxButton.m文件内容

#import "CheckBoxButton.h"

@interface CheckBoxButton()

@property(nonatomic,strong)IBInspectable UIImage* checkedStateImage;
@property(nonatomic,strong)IBInspectable UIImage* uncheckedStateImage;

@end

@implementation CheckBoxButton

-(id)init
{
    self = [super init];

    if(self)
    {
        [self addTarget:self action:@selector(switchState) forControlEvents:UIControlEventTouchUpInside];
    }

    return self;
}

-(id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];

    if(self)
    {
        [self addTarget:self action:@selector(switchState) forControlEvents:UIControlEventTouchUpInside];
    }

    return self;
}

-(id)initWithCoder:(NSCoder *)aDecoder
{
    self = [super initWithCoder:aDecoder];

    if(self)
    {
        [self addTarget:self action:@selector(switchState) forControlEvents:UIControlEventTouchUpInside];
    }

    return self;
}

-(void)setIsChecked:(BOOL)isChecked
{
    _isChecked = isChecked;

    if(isChecked)
    {
        [self setImage:self.checkedStateImage forState:UIControlStateNormal];
    }
    else
    {
        [self setImage:self.uncheckedStateImage forState:UIControlStateNormal];
    }
}

-(void)switchState
{
    self.isChecked = !self.isChecked;
    [self sendActionsForControlEvents:UIControlEventValueChanged];
}

@end

您可以在visual studio的属性检查器中为已选中/未选中以及isChecked属性设置图像.

要在storyboard或xib中添加CheckBoxButton,只需添加UIButton并在下一个图像上设置自定义类.

每当isChecked状态改变时,Button都会发送UIControlEventValueChanged事件.