改变文本行间距和字符间距

#import

@interface LineSpaceLabel : UILabel{
CGFloat charSpace_;
CGFloat lineSpace_;
}
@property(nonatomic, assign) CGFloat charSpace;
@property(nonatomic, assign) CGFloat lineSpace;

@end

#import "LineSpaceLabel.h"
#import
#import
@implementation LineSpaceLabel
@synthesize lineSpace = lineSpace_;
@synthesize charSpace = charSpace_;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
lineSpace_ = 5.0;
charSpace_ = 2.0;
}
return self;
}

-(void)awakeFromNib{
[super awakeFromNib];
lineSpace_ = 5.0;
charSpace_ = 2.0;
}

-(void)setCharSpace:(CGFloat)charSpace{
charSpace_ = charSpace;
[self setNeedsDisplay];
}
-(void)setLineSpace:(CGFloat)lineSpace{
lineSpace_ = lineSpace;
[self setNeedsDisplay];
}

-(void) drawTextInRect:(CGRect)requestedRect

{

//创建AttributeString

NSMutableAttributedString *string =[[NSMutableAttributedString alloc]initWithString:self.text];

//设置字体及大小

CTFontRef helveticaBold = CTFontCreateWithName((CFStringRef)self.font.fontName,self.font.pointSize,NULL);

[string addAttribute:(id)kCTFontAttributeName value:(id)helveticaBold range:NSMakeRange(0,[string length])];

//设置字间距

if(self.charSpace)

{
long number = self.charSpace;
CFNumberRef num = CFNumberCreate(kCFAllocatorDefault,kCFNumberSInt8Type,&number);
[string addAttribute:(id)kCTKernAttributeName value:(id)num range:NSMakeRange(0,[string length])];
CFRelease(num);
}

//设置字体颜色

[string addAttribute:(id)kCTForegroundColorAttributeName value:(id)(self.textColor.CGColor) range:NSMakeRange(0,[string length])];

//创建文本对齐方式

CTTextAlignment alignment = kCTLeftTextAlignment;

if(self.textAlignment == UITextAlignmentCenter)

{
alignment = kCTCenterTextAlignment;

}

if(self.textAlignment == UITextAlignmentRight)

{

alignment = kCTRightTextAlignment;

}

CTParagraphStyleSetting alignmentStyle;

alignmentStyle.spec = kCTParagraphStyleSpecifierAlignment;

alignmentStyle.valueSize = sizeof(alignment);

alignmentStyle.value = &alignment;

//设置文本行间距

CGFloat lineSpace = self.lineSpace;

CTParagraphStyleSetting lineSpaceStyle;

lineSpaceStyle.spec = kCTParagraphStyleSpecifierLineSpacingAdjustment;

lineSpaceStyle.valueSize = sizeof(lineSpace);

lineSpaceStyle.value =&lineSpace;

//设置文本段间距

CGFloat paragraphSpacing = 5.0;

CTParagraphStyleSetting paragraphSpaceStyle;

paragraphSpaceStyle.spec = kCTParagraphStyleSpecifierParagraphSpacing;

paragraphSpaceStyle.valueSize = sizeof(CGFloat);

paragraphSpaceStyle.value = &paragraphSpacing;



//创建设置数组

CTParagraphStyleSetting settings[ ] ={alignmentStyle,lineSpaceStyle,paragraphSpaceStyle};

CTParagraphStyleRef style = CTParagraphStyleCreate(settings ,3);

//给文本添加设置

[string addAttribute:(id)kCTParagraphStyleAttributeName value:(id)style range:NSMakeRange(0 , [string length])];

//排版

CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)string);

CGMutablePathRef leftColumnPath = CGPathCreateMutable();

CGPathAddRect(leftColumnPath, NULL ,CGRectMake(0 , 0 ,self.bounds.size.width , self.bounds.size.height));

CTFrameRef leftFrame = CTFramesetterCreateFrame(framesetter,CFRangeMake(0, 0), leftColumnPath , NULL);

//翻转坐标系统（文本原来是倒的要翻转下）

CGContextRef context = UIGraphicsGetCurrentContext();

CGContextSetTextMatrix(context , CGAffineTransformIdentity);

CGContextTranslateCTM(context , 0 ,self.bounds.size.height);

CGContextScaleCTM(context, 1.0 ,-1.0);

//画出文本

CTFrameDraw(leftFrame,context);

//释放

CGPathRelease(leftColumnPath);

CFRelease(framesetter);

CFRelease(helveticaBold);

[string release];

UIGraphicsPushContext(context);
}

@end