///bbs/?tid=74540
#import <UIKit/>
@interface TextFlowView : UIView {
//显示文本的标签
UILabel *_firstLabel;
UILabel *_secondLabel;
//定时器
NSTimer *_timer;
//显示的文本
NSString *_text;
//是否需要滚动
BOOL _needFlow;
//控件的框架大小
CGRect _frame;
//文本的字体
UIFont *_font;
//当前第一个控件的索引
NSInteger _startIndex;
//定时器每次执行偏移后，累计的偏移量之和
CGFloat _XOffset;
//文本显示一行，需要的框架大小
CGSize _textSize;
}
- (id)initWithFrame:(CGRect)frame Text:(NSString *)text;
- (void)setFont:(UIFont *)font;
- (void)setText:(NSString *)text;
@end
//
#import ""
@implementation TextFlowView
#pragma mark -
#pragma mark 内部调用
#define SPACE_WIDTH 50
#define LABEL_NUM 2
//改变一个TRect的起始点位置，但是其终止店点的位置不变，因此会导致整个框架大小的变化
- (CGRect)moveNewPoint:(CGPoint)point rect:(CGRect)rect
{
CGSize tmpSize;
tmpSize.height = rect.size.height + (rect.origin.y - point.y);
tmpSize.width = rect.size.width + (rect.origin.x - point.x);
returnCGRectMake(point.x, point.y, tmpSize.width, tmpSize.height);
}
//开启定时器
- (void)startRun
{
_timer = [NSTimerscheduledTimerWithTimeInterval:0.02target:selfselector:@selector(timerAction) userInfo:nilrepeats:YES];
}
//关闭定时器
- (void)cancelRun
{
if (_timer)
{
[_timerinvalidate];
}
}
//定时器执行的操作
- (void)timerAction
{
staticCGFloat offsetOnce = -1;
_XOffset += offsetOnce;
if (_XOffset + _textSize.width <= 0)
{
_XOffset += _textSize.width;
_XOffset += SPACE_WIDTH;
}
[selfsetNeedsDisplay];
}
//计算在给定字体下，文本仅显示一行需要的框架大小
- (CGSize)computeTextSize:(NSString *)text
{
if (text == nil)
{
returnCGSizeMake(0, 0);
}
CGSize boundSize = CGSizeMake(10000, 100);
CGSize stringSize = [_textsizeWithFont:_fontconstrainedToSize:boundSize lineBreakMode:UILineBreakModeWordWrap];
return stringSize;
}
- (id)initWithFrame:(CGRect)frame Text:(NSString *)text
{
self = [superinitWithFrame:frame];
if (self)
{
_text = [text retain];
_frame = frame;
//默认的字体大小
_font = [UIFontsystemFontOfSize:16.0F];
self.backgroundColor = [UIColorredColor];
//初始化标签
//判断是否需要滚动效果
_textSize = [selfcomputeTextSize:text];
//需要滚动效果
if (_textSize.width > frame.size.width)
{
_needFlow = YES;
[selfstartRun];
}
}
returnself;
}
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
CGContextRef context= UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [UIColorwhiteColor].CGColor);
// Drawing code
CGFloat startYOffset = (rect.size.height - _textSize.height)/2;
CGPoint origin = rect.origin;
if (_needFlow == YES)
{
// NSLog(@"OFFSETX:%f", _XOffset);
// NSLog(@"textwidth:%f",_textSize.width);
rect = [selfmoveNewPoint:CGPointMake(_XOffset, startYOffset) rect:rect];
// NSLog(@"rect X:%f Y:%f",, );
// NSLog(@"rect W:%f H:%f", , );
while (rect.origin.x <= rect.size.width+rect.origin.x)
{
[_textdrawInRect:rect withFont:_font];
rect = [selfmoveNewPoint:CGPointMake(rect.origin.x+_textSize.width+SPACE_WIDTH, rect.origin.y) rect:rect];
// NSLog(@"inner->rect X:%f Y:%f",, );
// NSLog(@"inner->rect W:%f H:%f", , );
}
}
else
{
//在控件的中间绘制文本
origin.x = (rect.size.width - _textSize.width)/2;
origin.y = (rect.size.height - _textSize.height)/2;
rect.origin = origin;
[_textdrawInRect:rect withFont:_font];
}
}
- (void)dealloc
{
[_textrelease];
[superdealloc];
}
#pragma mark -
#pragma mark 外部调用
- (void)setFont:(UIFont *)font
{
_font = font;
}
- (void)setText:(NSString *)text
{
[_textrelease];
_text = [text retain];
}
@end