Question

我使用protocol和init方法获得了AudioView类

 @protocol AudioViewDelegate <NSObject>
- (void)playButtonAction:(id)sender;  //(1)
- (void)playButtonActionforAudioTrack:(AudioTrack *)audioTrack;   //(2)

////

 - (id)initWithFrame:(CGRect)frame forAudioTrack:(AudioTrack *)audioTrack withButtonTag:(int)buttonTag

我使用音轨启动课程。我有播放按钮，然后我在屏幕上点击它，在方法（1）中委托我得到了按钮的发件人标签。

如何在代表中为播放曲目返回audioTrack？

========================= 类

 @protocol AudioViewDelegate <NSObject>
 - (void)playButtonAction:(id)sender;
 - (void)playButtonActionforAudioTrack:(AudioTrack *)audioTrack;
 @end

 @interface AudioView : UIView

 @property (nonatomic, strong) UILabel *audioTitle;
 @property (nonatomic, strong) UILabel *durationTitle;
 @property (nonatomic, strong) UIButton *playButton;

 @property (nonatomic, weak) id <AudioViewDelegate> delegate;

 - (id)initWithFrame:(CGRect)frame forAudioTrack:(AudioTrack *)audioTrack withButtonTag:(int)tag;

//。米

 - (id)initWithFrame:(CGRect)frame forAudioTrack:(AudioTrack *)audioTrack withButtonTag: (int)buttonTag
 {
self = [super initWithFrame:frame];
if (self) {
    self.frame = frame;
    self.tag = 0011;

    UIImageView *audioImageView = ..
    //[audioView addSubview:audioImageView];

    self.playButton = [UIButton buttonWithType:UIButtonTypeCustom];
    self.playButton.frame = audioImageView.frame;
    self.playButton.tag = buttonTag;
    [self.playButton setBackgroundImage:audioImageView.image forState:UIControlStateNormal];
    [self addSubview:self.playButton];


    [self.playButton addTarget:self.delegate action:@selector(playButtonAction:) forControlEvents:UIControlEventTouchUpInside];

    self.audioTitle = ..
    self.audioTitle.text = [NSString stringWithFormat:@"%@ - %@", audioTrack.artist, audioTrack.title];
    [self addSubview:self.audioTitle];

    self.durationTitle = ..
    [self addSubview:self.durationTitle];


}
return self;

}

////委托

创建视图

                 for (NSDictionary *dic in audioArray)
    {
        AudioTrack *audioTrack = [[AudioTrack alloc]init];
        audioTrack.artist = dic[@"artist"];
        audioTrack.title = dic[@"title"];
        audioTrack.duration = dic[@"duration"];
        audioTrack.url = dic[@"url"];
        [self.audioArray addObject:audioTrack];

             AudioView *audioView = [[AudioView alloc]initWithFrame:CGRectMake(10, currentHeight + audioInset, 300, 20) forAudioTrack:audioTrack withButtonTag:[audioArray indexOfObject:dic]];
        audioView.delegate = self;
        [view addSubview:audioView];

///实施委托

  - (void)playButtonAction:(id)sender
 {
int audioTag = [sender tag]; //here I get tag of tapped button
AudioTrack *sectedTrack = [self.audioArray objectAtIndex:audioTag];

我找到了很长的路。是否有可能在代理中获得音频跟踪？

Answer 1

这不是一个真正的答案，但评论很长。

好吧，如果A是一个想要将消息发送到它用作委托的其他类的对象的类，那么就像你所做的那样明智地为其他类中的所有方法声明一个协议，A想要呼叫。让我们称之为ProtocolA和方法method1和method2。 method2接收int作为参数。然后你有任何其他类B或C或类似的，符合协议ProtocolA。然后通常在A中使用名称为delegate的类型为id的变量。在某个时间点，当您要发送消息时，则调用[self.delegate method1];

这基本上都是关于委托模式的。你在哪里打电话给playButtonAction :?

委托中的返回值

1 个答案: