iOS开发练习之UIPickerView实现歌词翻滚效果

  1 #import "ViewController.h"
  2 #import "Word.h"
  3 #import "AudioPlayTool.h"
  4 #import "NSString+CJZ.h"
  5 
  6 
  7 @interface ViewController ()<UIPickerViewDataSource,UIPickerViewDelegate>
  8 
  9 @property (nonatomic,strong) NSArray *wordsArray;  // 存储对象word,word是根据歌词文件生成的一个对象,用来在PickerView显示一行的信息;
 10 @property (nonatomic,assign) int index;            // 播放索引;
 11 @property (nonatomic,strong) CADisplayLink *playLink;   // 定时器;
 12 @property (nonatomic,strong) AudioPlayTool * playTool;    // 播放类工具,用来播放歌曲,
 13 
 14 @property (weak, nonatomic) IBOutlet UIPickerView *wordListPicker;     // 显示歌词的PickerView
 15 
 16 
 17 @end
 18 
 19 @implementation ViewController
 20 - (IBAction)nextClick {
 21     [self.wordListPicker selectRow:self.index inComponent:0 animated:YES];
 22 }
 23 
 24 
 25 - (AudioPlayTool *)playTool
 26 {
 27     if (_playTool == nil) {
 28         _playTool = [[AudioPlayTool alloc]init];
 29     }
 30     return _playTool;
 31 }
 32 
 33 - (CADisplayLink *)playLink
 34 {
 35     if (_playLink == nil) {
 36         _playLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(updateInfo:)];
 37     }
 38     return _playLink;
 39 }
 40 
 41 - (NSArray *)wordsArray
 42 {
 43     if (_wordsArray == nil) {
 44         _wordsArray = [NSArray array];
 45     }
 46     return _wordsArray;
 47 }
 48 
 49 - (void)viewDidLoad
 50 {
 51     [super viewDidLoad];
 52     NSString *path = [[NSBundle mainBundle]pathForResource:@"Set Fire To The Rain_歌词.lrc" ofType:nil];
 53     self.wordsArray = [[Word alloc] wordsWithFilePath:path];
 54     [self.playTool prepareAudioWithName:@"31071114.mp3"];
 55     [self.playTool play];
 56     [self.playLink addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode];
 57   
 58 }
 59 
 60 #pragma mark - UIPickerView DataSource and Delegate;
 61 
 62 - (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component
 63 {
 64     return 40;
 65 }
 66 
 67 - (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView
 68 {
 69     return 1;
 70 }
 71 - (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component
 72 {
 73     return  self.wordsArray.count;
 74     
 75 }
 76 
 77 
 78 - (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
 79 {
 80     UILabel *textLable = [[UILabel alloc]initWithFrame:CGRectMake(0, 0, 320, 40)];
 81     Word *textWord = self.wordsArray[row];
 82     textLable.text = textWord.text;
 83     textLable.font = [UIFont systemFontOfSize:13];
 84     textLable.numberOfLines = 0;
 85     return textLable;
 86 }
 87  - (void)updateInfo:(CADisplayLink *)display
 88 {
 89     AVAudioPlayer *player = self.playTool.audioPlay;
 90     double currentTime = player.currentTime;
 91     NSString *change2Time = [NSString getMinuteSecondWithSecond:currentTime];
 92     double compareTime = [NSString getTimeWithString:change2Time];
 93     
 94    for (int i = 0; i < self.wordsArray.count; i++)
 95     {
 96         Word *beginW = self.wordsArray[i];
 97         double wordTime = [NSString getTimeWithString:beginW.time];
 98         Word *nextW = nil;
 99         int next = i + 1;
100         if (next < self.wordsArray.count) {
101             nextW = self.wordsArray[next];
102             if (compareTime >= wordTime && compareTime <= [NSString getTimeWithString:nextW.time])
103             {
104                dispatch_async(dispatch_get_main_queue(), ^{
105                 self.index = i + 1;
106                 [self nextClick];
107              });
108               break;
109             }
110         }
111     }
112 }
113 
114 
115 
116 @end

 1 #import <Foundation/Foundation.h>
 2 
 3 @interface Word : NSObject
 4 @property (nonatomic,copy)NSString *time;
 5 @property (nonatomic,copy)NSString *text;
 6 
 7 + (instancetype)wordWithString:(NSString *)string;    //工具方法,根据特定的字符串,生成word对象;
 8 - (instancetype)initWithString:(NSString *)string;    // 同上;
 9 
10 - (NSArray *)wordsWithFilePath:(NSString *)path;      // 根据文件路径,生成包含多个word对象的数组;
11 
12 @end

 1 #import "Word.h"
 2 
 3 @implementation Word
 4 
 5 - (instancetype)initWithString:(NSString *)string
 6 {
 7     if (self = [super init]) {
 8         NSRange  rangeOne = NSMakeRange(1, 5);
 9         self.time = [string substringWithRange:rangeOne];
10         self.text = [string substringFromIndex:10];
11     }
12     return self;
13 }
14 
15 + (instancetype)wordWithString:(NSString *)string
16 {
17     return [[self alloc]initWithString:string];
18 }
19 
20 - (NSArray *)wordsWithFilePath:(NSString *)path
21 {
22     NSError *error = nil;
23     NSString *original = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:&error];
24     NSArray *stringArray = [original componentsSeparatedByString:@"\n"];
25     NSMutableArray *lastArray = [NSMutableArray array];
26     for (NSString *string in stringArray) {
27         if ((string.length > @"[00:00:00]".length ) && [string hasPrefix:@"[0"]) {
28             [lastArray addObject:string];
29         }
30     }
31     NSMutableArray *wordsArray = [NSMutableArray array];
32     for (NSString *string in lastArray) {
33         Word *singleWord = [Word wordWithString:string];
34         [wordsArray addObject:singleWord];
35     }
36     return [wordsArray copy];
37 }
38 @end

 1 #import <Foundation/Foundation.h>
 2 #import <AVFoundation/AVFoundation.h>
 3 
 4 @class AVAudioPlayer ;
 5 @interface AudioPlayTool : NSObject
 6 
 7 @property (nonatomic,strong,readonly ) AVAudioPlayer *audioPlay;
 8 
 9 - (void)prepareAudioWithName:(NSString *)name;
10 - (void)play;
11 - (void)stop;
12 - (void)pause;
13 
14 @end

 1 #import "AudioPlayTool.h"
 2 
 3 
 4 @interface AudioPlayTool()
 5 
 6 
 7 @end
 8 
 9 @implementation AudioPlayTool
10 
11 
12 - (void)prepareAudioWithName:(NSString *)name
13 {
14    NSError *error = nil;
15     NSString *songPath = [[NSBundle mainBundle] pathForResource:name ofType:nil];
16      AVAudioPlayer *player = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:songPath] error:&error];
17     if (error) {
18               return;
19     }
20     [player prepareToPlay];
21     _audioPlay = player;
22 }
23 
24 - (void)play
25 {
26     if (![_audioPlay isPlaying]) {
27         [self.audioPlay play];
28     
29     }
30 }
31 
32 - (void)stop
33 {
34     [self.audioPlay stop];
35 }
36 
37 - (void)pause
38 {
39     if ([_audioPlay isPlaying]) {
40         [self.audioPlay pause];
41     
42     }
43 }
44 
45 @end

#import <Foundation/Foundation.h>

@interface NSString (CJZ)


/**
 *  返回分与秒的字符串 如:01:60
 */
+(NSString *)getMinuteSecondWithSecond:(NSTimeInterval)time;

+(NSTimeInterval) getTimeWithString:(NSString *)string;
@end

#import "NSString+CJZ.h"

@implementation NSString (CJZ)

+(NSString *)getMinuteSecondWithSecond:(NSTimeInterval)time{
    
    int minute = (int)time / 60;
    int second = (int)time % 60;
    
    if (second > 9) {
        return [NSString stringWithFormat:@"%d:%d",minute,second];
    }
    return [NSString stringWithFormat:@"%d:0%d",minute,second];
}

+ (NSTimeInterval)getTimeWithString:(NSString *)string{
    if (string.length == 5) {
        double first = [[string substringWithRange:NSMakeRange(1, 1)] doubleValue];
        double second = [[string substringFromIndex:3] doubleValue];
        return first + second * 0.01;
    }
    double first = [[string substringWithRange:NSMakeRange(0, 1)] doubleValue];
    double second = [[string substringFromIndex:2] doubleValue];
    return first + second * 0.01;
}

@end