UIButton的两种动作方法;下一步追踪： [英] Two action methods for an UIButton; next track and seek forward:

问题描述

我正在创建一个音乐播放器应用程序，它需要从一个按钮调用2个动作，一个通过触摸内部事件跳到下一个轨道，以及其他快速转发'长按'的curenttrack。我不知道哪个事件指向这个长按，我认为它是触地，但它只在按住按钮时起作用。当我释放按钮时，轨道被跳到下一个项目。请帮助

I am creating a music player application and it need that 2 actions to be called from a single button, one to skip to next track by touch up inside event and other to fast forward the curenttrack incase of a 'long press'. I don't know which event is pointing to this long press, i thought it to be touch down, but it worked only while holding the button. When i released the button, the track was skipped to next item. pls help

AVAudioPlayer *appSoundPlayer;// declared in .h file

在m文件中，方法：

-(void)seekForwards{
NSTimeInterval timex;
timex = appSoundPlayer.currentTime;
        timex = timex+5; // forward 5 secs

        appSoundPlayer.currentTime = timex;
        timex = 0;
}

推荐答案

就我个人而言，我只是跟踪按钮的状态，在视图控制器上或按钮子类中有一个整数。如果您跟踪按钮的功能，您可以控制每个操作的功能。在你的.h文件中输入这样的东西：

Personally I'd just track the button's state with an integer on your view controller or within a button subclass. If you track what the button is doing you can control what each of the actions do. In your .h file put in some stuff like this:

enum {
    MyButtonScanning,
    MyButtonStalling,
    MyButtonIdle
};



@interface YourClass : UIViewController {
    NSInteger buttonModeAt;
}
@property (nonatomic) NSInteger buttonModeAt;
-(IBAction)buttonPushedDown:(id)sender;
-(void)tryScanForward:(id)sender;
-(IBAction)buttonReleasedOutside:(id)sender;
-(IBAction)buttonReleasedInside:(id)sender;
@end

然后在你的.m文件中输入一些东西：

And then in your .m file throw in some of this stuff:

@implementation YourClass
///in your .m file
@synthesize buttonModeAt;


///link this to your button's touch down
-(IBAction)buttonPushedDown:(id)sender {
    buttonModeAt = MyButtonStalling;
    [self performSelector:@selector(tryScanForward:) withObject:nil afterDelay:1.0];
}

-(void)tryScanForward:(id)sender {
    if (buttonModeAt == MyButtonStalling) {
        ///the button was not released so let's start scanning
        buttonModeAt = MyButtonScanning;

        ////your actual scanning code or a call to it can go here
        [self startScanForward];
    }
}

////you will link this to the button's touch up outside
-(IBAction)buttonReleasedOutside:(id)sender {
    if (buttonModeAt == MyButtonScanning) {
        ///they released the button and stopped scanning forward
        [self stopScanForward];
    } else if (buttonModeAt == MyButtonStalling) {
        ///they released the button before the delay period finished
        ///but it was outside, so we do nothing
    }

    self.buttonModeAt = MyButtonIdle;
}

////you will link this to the button's touch up inside
-(IBAction)buttonReleasedInside:(id)sender {
    if (buttonModeAt == MyButtonScanning) {
        ///they released the button and stopped scanning forward
        [self stopScanForward];
    } else if (buttonModeAt == MyButtonStalling) {
        ///they released the button before the delay period finished so we skip forward
        [self skipForward];
    }

    self.buttonModeAt = MyButtonIdle;

}

之后只需将按钮的动作链接到我的动作在IBactions之前的评论中指出。我没有测试过这个，但它应该可以工作。

After that just link the button's actions to what I've noted in the comments before the IBactions. I haven't tested this but it should work.

这篇关于UIButton的两种动作方法;下一步追踪：的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！