Question

当用户按下单元格中的按钮时，我正在尝试为自定义UITableViewCell中的一些项目制作动画。我设置了addTarget：并添加了一种方法来为单元格中的项目设置动画。我为按钮设置了一个标签，这样我就可以得到索引。在方法中，我调用cellForRowAtIndexPath：来获取按钮被调用的单元格。我正在将cellForRowAtIndexPath返回的对象转换为我的自定义单元格。拥有自定义单元格后，我会对对象执行动画。问题是动画没有发生。当我尝试在单元格中的一个项目上设置属性时，它也不起作用。自定义单元格没有返回零，所以我不确定这个问题。我做错了什么？

以下是我用来调用动画的代码

-(void)favButtonPressed:(id)sender{        
FavoritesCell *favCell = (FavoritesCell *)[self tableView:self.tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:[sender tag] inSection:0]];

[UIView animateWithDuration:0.2 animations:^{
    favCell.picButton.alpha = 0.5;
}  completion:nil];
}

Answer 1

你可以通过使用下面的自定义委托来实现这一点，希望这有助于你。

我举了一个你的案例的例子，希望这有助于你

在自定义单元格calss中定义委托协议，如下所示在FavoritesCell.h

#import <UIKit/UIKit.h>
@class FavoritesCell;

@protocol CellActionDelegate <NSObject>
- (void)doAnimationForCell:(FavoritesCell *)cell forButton:(UIButton *)picButton; //in this u can pass the cell itself
@end

@interface FavoritesCell : UITableViewCell
@property (nonatomic,retain)UIButton *picButton; //i am doing a simple test, say this is your pic button
@property (nonatomic,assign) id<CellActionDelegate>cellDelegate;
@end

并在FavoritesCell.m档案

#import "FavoritesCell.h"

@implementation FavoritesCell
@synthesize cellDelegate;
@synthesize picButton = _picButton;

- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
{
   self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
   if (self) {
      // Initialization code
      _picButton = [[UIButton alloc]initWithFrame:CGRectMake(20, 3, 100, 100)];
      //set the property // for test

      [_picButton addTarget:self action:@selector(favButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
      [_picButton.layer setCornerRadius:50];
      [_picButton.layer setMasksToBounds:YES];
      [_picButton.layer setBorderColor:[[UIColor blackColor]CGColor]];
      [_picButton.layer setBorderWidth:5];
      _picButton.backgroundColor = [UIColor greenColor];
      [self.contentView addSubview:_picButton];
    }
    return self;

}

- (void)setSelected:(BOOL)selected animated:(BOOL)animated  
{
  [super setSelected:selected animated:animated];

 // Configure the view for the selected state
}   

- (void)favButtonPressed:(UIButton *)sender
{
   //or you can do the animation hear only no need to delegate to controller form cell

   if([self.cellDelegate respondsToSelector:@selector(doAnimationForCell:forButton:)])
   {
      [self.cellDelegate doAnimationForCell:self forButton:sender]; //call this method
   }
}

@end

<{1>}文件中的

ViewController.h

ViewController.m文件中的

#import <UIKit/UIKit.h>
#import "FavoritesCell.h" //import it

 @interface ViewController : UIViewController<UITableViewDataSource,UITableViewDelegate,CellActionDelegate> //confirms to delegate

 //.... other stuffs

Answer 2

我想你想要这样的东西：

-(void)favButtonPressed:(id)sender
{        
    CGPoint buttonPosition = [sender convertPoint:CGPointZero toView:self.myTableView];

    // or try this one alternatively if the above line give wrong indexPath
    //CGPoint buttonPosition = [sender convertPoint:((UIButton *)sender).center toView:self.myTableView];

    NSIndexPath *indexPath = [self.myTableView indexPathForRowAtPoint:buttonPosition];

    // I assume "self" here is your view controller 
    FavoritesCell *favCell = (FavoritesCell *)[self.myTableView cellForRowAtIndexPath:indexPath];

    [UIView animateWithDuration:0.2 animations:^{
        favCell.picButton.alpha = 0.5;
    }  completion:nil];
}

在自定义UITableViewCell上执行动画

2 个答案: