使用删除功能创建自定义UIButton类

I have a grid of UIButtons. When I hit an 'edit' button, I want a delete button to appear over each of these buttons, which when pressed, deletes the button (and associated data). A bit like apple's home screen, when you hold down a button and it starts to wiggle with an X in the corner.

我有一个UIButtons网格。当我点击“编辑”按钮时,我想在每个按钮上显示一个删除按钮,按下该按钮时,删除按钮(和相关数据)。有点像苹果的主屏幕,当你按住一个按钮时,它开始在角落里摆动一个X。

According to this post: Subclass UIButton to add a property I can use Associative References to add a property to each of my buttons. I've tried to add a UIButton as a property of my custom UIButton but I can't seem to get it to appear and have the feeling this isn't the right way to go. Here's my custom button main:

根据这篇文章:Subclass UIButton添加一个属性我可以使用Associative References为我的每个按钮添加一个属性。我试图添加一个UIButton作为我的自定义UIButton的属性,但我似乎无法让它出现并感觉这不是正确的方法。这是我的自定义按钮主要:

    #import "UIButton+Property.h"
#import <objc/runtime.h>

@implementation UIButton(Property)

static char UIB_DELETEBUTTON_KEY;

@dynamic deleteButton;


- (void)setDeleteButton:(UIButton *)deleteButton {
    deleteButton = [UIButton buttonWithType:UIButtonTypeInfoDark];
    deleteButton.frame = CGRectMake(100, 100, 50, 50);
    objc_setAssociatedObject(self, &UIB_DELETEBUTTON_KEY, deleteButton, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (UIButton *)deleteButton {
    return (UIButton *)objc_getAssociatedObject(self, &UIB_DELETEBUTTON_KEY);
}

@end

And here's where I add the buttons programmatically:

这是我以编程方式添加按钮的位置:

//Create a custom button for each custom book doc
for (int i = 0; i < [customBookDocs count]; ++i) {
    BookDoc *customBookDoc = [customBookDocs objectAtIndex:i];
    NSString *bookTitle = customBookDoc.book.title;

    //create a button for each book
    CGRect frame = CGRectMake(xCoord, yCoord, 200, 200);
    UIButton *bookButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    bookButton.bookDoc = customBookDoc;
    [bookButton setFrame:frame];
    [bookButton setTitle:bookTitle forState:UIControlStateNormal];
    [bookButton addTarget:self action:@selector(bookButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
    xCoord += 250;

    [self.view addSubview:bookButton];
    [self.view addSubview:bookButton.deleteButton];
}

Is there an easier more sensible way to do this? Or am I on the right track?

有没有更容易更明智的方法来做到这一点?还是我走在正确的轨道上?

1 个解决方案

#1

ORIGINAL RESPONSE BEGAN:

原始回应开始:

... Someone else may have more to say about that, but I'm not sure why you'd need to use object association here. You can certainly add another button to your button as a property using regular subclassing, which is the route that I would take. ...

......其他人可能有更多话要说,但我不确定你为什么需要在这里使用对象关联。您当然可以使用常规子类化向您的按钮添加另一个按钮作为属性,这是我将采取的路径。 ...

EDITS BELOW:

I thought that I had subclassed a UI control directly, but I realized that I was mistaken when I went to look for the code. @Joe rightly pointed out in the comments that there are issues with directly subclassing UI controls.

我以为我直接将子控件子类化了,但是当我去寻找代码时,我意识到自己错了。 @Joe在评论中正确地指出直接子类化UI控件存在问题。

I was able to implement something like the functionality you described without using Associated Objects, by creating a wrapper class to hold the button and its related delete button. It works, but it's not very flexible, so I would generally recommend @Joe's method as a better solution.

通过创建一个包装类来保存按钮及其相关的删除按钮,我能够实现类似于您所描述的功能而不使用关联对象。它有效,但它不是很灵活,所以我一般会推荐@ Joe的方法作为更好的解决方案。

Here's the relevant code:

这是相关的代码:

I threw all of the code into the appDelegate to keep it simple. I don't recommend that in real life.

我把所有代码都放到appDelegate中以保持简单。我不建议在现实生活中。

AppDelegate.m:

@implementation AppDelegate

@synthesize window = _window;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

    self.window.backgroundColor = [UIColor whiteColor];

    UIButton *toggleDeleteButtons = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [toggleDeleteButtons setFrame:CGRectMake(20, 45, 280, 45)];
    [toggleDeleteButtons setTitle:@"Toggle Delete" forState:UIControlStateNormal];
    [toggleDeleteButtons addTarget:self action:@selector(toggleDeleteButtonAction) forControlEvents:UIControlEventTouchUpInside];
    [[self window] addSubview:toggleDeleteButtons];

    ButtonWrapper *myButtonWrapper = [[ButtonWrapper alloc] init];
    [[myButtonWrapper button] setFrame:CGRectMake(20, 100, 200, 45)];
    [[myButtonWrapper button] setTitle:@"This is my button" forState:UIControlStateNormal];
    [[myButtonWrapper deleteButton] addTarget:self action:@selector(buttonDeleteRequested:) forControlEvents:UIControlEventTouchUpInside];
    [[myButtonWrapper deleteButton] setTag:0];
    [[self window] addSubview:[myButtonWrapper button]];
    buttonWrapper1 = myButtonWrapper;

    // Added instance called anotherButtonWrapper with tag 1, as above

    // Added instance called stillAnotherButtonWrapper with tag 2, as above

    [self.window makeKeyAndVisible];
    return YES;
}

- (void)toggleDeleteButtonAction {
    static BOOL deleteButtonsShown;

    [buttonWrapper1 showDeleteButton:!deleteButtonsShown];
    [buttonWrapper2 showDeleteButton:!deleteButtonsShown];
    [buttonWrapper3 showDeleteButton:!deleteButtonsShown];
    deleteButtonsShown = !deleteButtonsShown;
}

- (void)buttonDeleteRequested:(UIButton *)deleteButton {
    // delete the specified button here
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Delete" message:[NSString stringWithFormat:@"Delete was pressed on button %i",[deleteButton tag]]delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [alert show];
}

ButtonWrapper.m:

@implementation ButtonWrapper

@synthesize button;
@synthesize deleteButton;

- (ButtonWrapper *)init {
    ButtonWrapper *newWrapper = [ButtonWrapper alloc];

    UIButton *myButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [myButton setFrame:CGRectZero];

    UIButton *myDeleteButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    [myDeleteButton setFrame:CGRectMake(0, 0, 100, 40)];
    [myDeleteButton setTitle:@"Delete" forState:UIControlStateNormal];
    [myDeleteButton setHidden:TRUE];
    [myButton addSubview:myDeleteButton];

    [newWrapper setButton:myButton];
    [newWrapper setDeleteButton:myDeleteButton];

    return newWrapper;
}

- (void)showDeleteButton:(BOOL)showButton {
    if (showButton) {
        [[self deleteButton] setHidden:FALSE];
        [[self deleteButton] setEnabled:TRUE];    }
    else {
        [[self deleteButton] setHidden:TRUE];
        [[self deleteButton] setEnabled:FALSE];
    }
}
@end

This solution did not require me to implement all of the UI properties, but it did require extra work to hook up the embedded delegates, which is cumbersome. There may be a way to pass the delegates into the wrapper at initialization, but I couldn't make it work.

这个解决方案并不需要我实现所有的UI属性,但它确实需要额外的工作来挂钩嵌入的委托,这很麻烦。可能有一种方法可以在初始化时将委托传递给包装器,但我无法使其工作。