iphone中自定义单选按钮的默认选择

Posted 2023-04-15

【中文标题】iphone中自定义单选按钮的默认选择

【英文标题】：default selection on custom Radio Button in iphone

【发布时间】：2013-06-08 07:55:14

【问题描述】：

我想在我的应用中实现单选按钮 我使用了https://www.cocoacontrols.com/controls/radiobutton（可可控制单选按钮）。 我希望默认情况下始终选择其中之一。我怎样才能做到这一点。

我的单选按钮代码如下：

  RadioButton *radioButtonForDay = [[RadioButton alloc] initWithGroupId:@"first group" index:0 ];
RadioButton *radioButtonForWeek = [[RadioButton alloc] initWithGroupId:@"first group" index:1 ];
RadioButton *radioButtonForMonth = [[RadioButton alloc] initWithGroupId:@"first group" index:2 ];

radioButtonForDay.frame = CGRectMake(40,65,22,28);
radioButtonForWeek.frame = CGRectMake(130,65,22,28);
radioButtonForMonth.frame = CGRectMake(195,65,22,28);

[self.view addSubview:radioButtonForDay];
[self.view addSubview:radioButtonForWeek];
[self.view addSubview:radioButtonForMonth];

[RadioButton addObserverForGroupId:@"first group" observer:self];

RadioButton.m

`

导入“RadioButton.h”

@interface RadioButton() -（无效）默认初始化； -(void)otherButtonSelected:(id)sender; -(void)handleButtonTap:(id)sender; @结束

@implementation 单选按钮

@synthesize groupId=_groupId; @synthesize index=_index;

静态常量 NSUInteger kRadioButtonWidth=22; 静态常量 NSUInteger kRadioButtonHeight=22;

静态 NSMutableArray *rb_instances=nil; 静态 NSMutableDictionary *rb_observers=nil;

pragma mark - 观察者

+(void)addObserverForGroupId:(NSString*)groupId 观察者:(id)observer 如果（！rb_observers） rb_observers = [[NSMutableDictionary alloc] init];

if ([groupId length] > 0 && observer) 
    [rb_observers setObject:observer forKey:groupId];
    // Make it weak reference
    //[observer release];

pragma mark - 管理实例

+(void)registerInstance:(RadioButton*)radioButton 如果（！rb_instances） rb_instances = [[NSMutableArray alloc] init];

[rb_instances addObject:radioButton];
// Make it weak reference
//[radioButton release];

pragma mark - 类级处理程序

+(void)buttonSelected:(RadioButton*)radioButton

// Notify observers
if (rb_observers) 
    id observer= [rb_observers objectForKey:radioButton.groupId];

    if(observer && [observer respondsToSelector:@selector(radioButtonSelectedAtIndex:inGroup:)])
        [observer radioButtonSelectedAtIndex:radioButton.index inGroup:radioButton.groupId];
    


// Unselect the other radio buttons
if (rb_instances) 
    for (int i = 0; i < [rb_instances count]; i++) 
        RadioButton *button = [rb_instances objectAtIndex:i];
        if (![button isEqual:radioButton] && [button.groupId isEqualToString:radioButton.groupId]) 
            [button otherButtonSelected:radioButton];
        
    

pragma mark - 对象生命周期

-(id)initWithGroupId:(NSString*)groupId index:(NSUInteger)index self = [超级初始化];

if (self) 
    _groupId = groupId;
    _index = index;
   // _selected = selected;

    [self defaultInit];

return  self;

(无效)dealloc //[_groupId 释放]; // [_按钮释放]; // [超级释放];

pragma mark - 点击处理

-(void)handleButtonTap:(id)sender [_button setSelected:YES]; [RadioButton buttonSelected:self];

-(void)otherButtonSelected:(id)sender // 当其他单选按钮实例被选中时调用 如果（_button.selected） [_button setSelected:NO];

pragma mark - RadioButton 初始化

-(void)defaultInit // 设置容器视图 self.frame = CGRectMake(0, 0, kRadioButtonWidth, kRadioButtonHeight);

// Customize UIButton
_button = [UIButton buttonWithType:UIButtonTypeCustom];

_button.frame = CGRectMake(0, 0,kRadioButtonWidth, kRadioButtonHeight);
_button.adjustsImageWhenHighlighted = NO; 

[_button setImage:[UIImage imageNamed:@"RadioButton-Unselected"] forState:UIControlStateNormal];
[_button setImage:[UIImage imageNamed:@"RadioButton-Selected"] forState:UIControlStateSelected];

[_button addTarget:self action:@selector(handleButtonTap:) forControlEvents:UIControlEventTouchUpInside];

[self addSubview:_button];

[RadioButton registerInstance:self];

@结束 `

【参考方案1】：

最初将所选图像设置为您的任何按钮。

[yourBtn setImage:yourImage forState:UIControlStateNormal]; 

根据您的代码，只需将 handleButtonTap 方法放入 RadioButton.h

-(void)handleButtonTap:(id)sender;  

在RadioButtonViewController.m 访问您要选择的按钮

第二个按钮（即 RadioButton *rb2）

for (id subView in [rb2 subviews]) 
    if ([subView isKindOfClass:[UIButton class]]) 
        [rb2 handleButtonTap:subView];
    

【讨论】：

@Rajneesh071：我也曾在我的应用程序中使用过这段代码，但它正在崩溃并释放 UIViewController 的对象。你能帮我解决这个问题吗？

【参考方案2】：

试试这个：

默认选择

        [btnR setImage:[UIImage imageNamed:@"btnCheck.png"] forState:UIControlStateNormal];
        [btnG setImage:[UIImage imageNamed:@"btnUnCheck.png"] forState:UIControlStateNormal];
        [btnB setImage:[UIImage imageNamed:@"btnUnCheck.png"] forState:UIControlStateNormal];

当您转到下一个视图时，只需检查条件......

    UIImage* selectedImg=[UIImage imageNamed:@"btnCheck.png"]; //btnCheck.png your image name
    if (btnR.imageView.image == selectedImg  || btnG.imageView.image == selectedImg || btnB.imageView.image == selectedImg)
    
             //One of them is selected
    
    else 
       NSLog(@"Please Select At least One Color" );