如何在iphone中創建多個具有選取框效果的uiview動畫

Question

我需要創建多個具有MARQUEE效果的UIView，如HTML <marquee>標記。

我首先需要動態創建UIView。

爲動態創建的UIView添加MARQUEE效果之後。

任何幫助將不勝感激。

Answer 1

您的意思是一個視圖，它可以顯示比視圖寬度更寬的字符串集合，它通過從右向左緩慢滾動顯示它？你需要建立它。我做了一次，像這樣繼承UIScrollView：

// CrawlView.h 

#import <UIKit/UIKit.h> 

@interface CrawlView : UIScrollView 

@property (assign, nonatomic) NSTimeInterval period; 
@property (strong, nonatomic) NSMutableArray *messages; 

- (void)go; 

@end 


// CrawlView.m 

#import "CrawlView.h" 

// distance between neighboring strings. could make this a public property 
#define kPADDING 16.0 

@interface CrawlView() 

@property (assign, nonatomic) CGFloat messagesWidth; 

@end 

@implementation CrawlView 

@synthesize period=_period; 
@synthesize messages=_messages; 
@synthesize messagesWidth=_messagesWidth; 

- (void)buildSubviews { 

    for (UIView *subview in [self subviews]) { 
     if ([subview isKindOfClass:[UILabel self]]) { 
      [subview removeFromSuperview]; 
     } 
    } 

    CGFloat xPos = kPADDING; 

    for (NSString *message in self.messages) { 
     UILabel *label = [[UILabel alloc] initWithFrame:CGRectZero]; 
     label.text = message; 
     CGSize size = [message sizeWithFont:label.font]; 
     CGFloat width = size.width + kPADDING; 
     label.frame = CGRectMake(xPos, 0.0, width, self.frame.size.height); 
     [self addSubview:label]; 
     xPos += width; 
    } 
    self.messagesWidth = xPos; 
    self.contentSize = CGSizeMake(xPos, self.frame.size.height); 
    self.contentOffset = CGPointMake(-self.frame.size.width, 0.0); 
} 

- (void)setMessages:(NSMutableArray *)messages { 

    if (_messages != messages) { 
     _messages = messages; 
     [self buildSubviews]; 
    } 
} 

- (void)go { 

    if (!self.period) self.period = self.messagesWidth/100; 
    // so it always takes about the same (fudged, but reasonable) amount of time to scroll the whole array 

    [UIView animateWithDuration:self.period 
          delay:0.0 
         options:UIViewAnimationOptionCurveLinear |UIViewAnimationOptionRepeat 
        animations:^{ 
         self.contentOffset = CGPointMake(self.messagesWidth, 0.0); 
        } completion:^(BOOL finished){}]; 
} 


@end