iOS 文字动画,文字逐个显示

随手记:

    对于iOS文字动画,首先想到的应该是基于CoreText框架将文字每个都写出来,加上定时器给定每个字显示的时间,这是一种思维方式:

#import "ViewController.h"
#import 
@interface ViewController ()
{
    NSMutableArray *labels;
    NSMutableArray *numArr;
    NSMutableArray *dataArr;
}
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
}

- (IBAction)buttonClick:(id)sender {
    UIView *vi = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
    vi.backgroundColor = [UIColor whiteColor];
    [self.view addSubview:vi];
    
    CATextLayer *textLayer = [CATextLayer layer];
    textLayer.frame = vi.bounds;
    textLayer.contentsScale = [UIScreen mainScreen].scale;
    [vi.layer addSublayer:textLayer];
    textLayer.alignmentMode = kCAAlignmentJustified;
    textLayer.wrapped = YES;
    
    UIFont *font = [UIFont fontWithName:@"EuphemiaUCAS-Bold" size:12];
    NSArray *familyNames = [UIFont familyNames];
    for( NSString *familyName in familyNames ){
        
        printf( "Family: %s \n", [familyName UTF8String] );
        
        NSArray *fontNames = [UIFont fontNamesForFamilyName:familyName];
        for( NSString *fontName in fontNames ){
            
            printf( "\tFont: %s \n", [fontName UTF8String] );
        }
    }
    
    NSString *str = @"还是月西江更有意境:日暮江水远,入夜随风迁,秋叶乱水月...";
    
    NSMutableAttributedString *string = nil;
    string = [[NSMutableAttributedString alloc] initWithString:str];
    CFStringRef fontName = (__bridge CFStringRef)(font.fontName);
    CGFloat fontSize = font.pointSize;
    CTFontRef fontRef = CTFontCreateWithName(fontName, fontSize, NULL);
    NSDictionary *attribs = @{
                              (__bridge id)kCTForegroundColorAttributeName:(__bridge id)[UIColor whiteColor].CGColor,
                              (__bridge id)kCTFontAttributeName:(__bridge id)fontRef
                              };
    [string setAttributes:attribs range:NSMakeRange(0, str.length)];
    
    dataArr = [NSMutableArray arrayWithObjects:(__bridge id _Nonnull)(fontRef),attribs,string,str,textLayer, nil];
    numArr = [NSMutableArray array];
    for (int i = 0; i < str.length; i++) {
        [numArr addObject:[NSNumber numberWithInt:i]];
        [self performSelector:@selector(changeToBlack) withObject:nil afterDelay:0.1 * i];
    }
    CFRelease(fontRef);
    
}

- (void)changeToBlack {
    CTFontRef fontRef = (__bridge CTFontRef)(dataArr[0]);
    NSMutableAttributedString *string = dataArr[2];
    NSNumber *num = [numArr firstObject];
    int y = [num intValue];
    NSDictionary *attribs = dataArr[1];
    attribs = @{
                (__bridge id)kCTForegroundColorAttributeName:(__bridge id)[UIColor blackColor].CGColor,
                (__bridge id)kCTFontAttributeName:(__bridge id)fontRef
                };
    [string setAttributes:attribs range:NSMakeRange(y, 1)];
    if (numArr.count > 1) {
        [numArr removeObjectAtIndex:0];
    }
    CATextLayer *textLayer = [dataArr lastObject];
    textLayer.string = string;
}

    是不是还有另一种思维方式呢,答案是有的,只需在label上加一个白色的挡板就OK了,当然,别忘记了把挡板的anchorPoint变为(1,0.5),让它从左边开始变小:

#import "ViewController.h"

@interface ViewController ()
{
    UIView *myView;
    BOOL isclick;
}
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 200, 50)];
    label.text = @"我其实很喜欢你的,初音";
    [self.view addSubview:label];
    
    myView = [[UIView alloc] initWithFrame:CGRectMake(200, 100, 200, 50)];
    myView.backgroundColor = [UIColor whiteColor];
    myView.layer.anchorPoint = CGPointMake(1, 0.5);
    [self.view addSubview:myView];
}
- (IBAction)buttonClick:(id)sender {
    if (!isclick) {
        [UIView animateWithDuration:1.0 delay:0 options:UIViewAnimationOptionLayoutSubviews animations:^{
            myView.bounds = CGRectMake(0, 0, 10, 50);
        } completion:^(BOOL finished) {
        }];
    } else {
        [UIView animateWithDuration:1.0 delay:0 options:UIViewAnimationOptionLayoutSubviews animations:^{
            myView.bounds = CGRectMake(0, 0, 200, 50);
        } completion:^(BOOL finished) {
        }];
    }
    isclick = !isclick;
}

 demo下载地址:http://download.csdn.net/download/et295394330/9406943