CoreText 轻松设置字体大小，间距，行间距，段间距,算高度

来源：互联网发布：约瑟夫环 java 编辑：程序博客网时间：2024/05/16 11:19

[http://blog.sina.com.cn/s/blog_691a202f0101bq6q.html]

下面主要讲，如何设置字体，间距，并计算（带特定段间距，行间距，字间距，字大小）文字的高度。

1.首先当然是导入CoreText.framework,如果这个不会，下面的你就别看了！

2 自己写一个继承UIView的类，我写的叫 MyView

.h代码如下：

#import

@interface Myview : UIView

@property(nonatomic,retain)NSString*text; //要画的文字

@property(nonatomic,assign)CGFloatfont; //字体大小

@property(nonatomic,assign)CGFloatcharacter; //字间距

@property(nonatomic,assign)CGFloatline; //行间距

@property(nonatomic,assign)CGFloatparagraph;//段落间距

@end

看到上面的5个属性，就是我们自己，可以随意设置的。

.m部分的全部代码如下，看不懂没关系，会用就行（东西都是，先了解，会用，然后理解）

#import "Myview.h"

#import

@implementation Myview

-(void)dealloc

{

[_textrelease];

[superdealloc];

}

- (id)initWithFrame:(CGRect)frame

{

self = [superinitWithFrame:frame];

if (self) {

self.font =15;

self.text= @"请给myview.text赋值";

self.line =10;

self.paragraph =20;

self.character =4;

}

return self;

}

-(void)drawRect:(CGRect)rect

{

[superdrawRect:rect];

//创建AttributeStringfdsa

NSMutableAttributedString*string = [[NSMutableAttributedStringalloc]

initWithString:self.text];

//创建字体以及字体大小

CTFontRef helvetica =CTFontCreateWithName(CFSTR("Helvetica"),self.font,NULL);

CTFontRef helveticaBold =CTFontCreateWithName(CFSTR("Helvetica"),self.font,NULL);

//字体，把helvetica 样式加到整个，string上

[string addAttribute:(id)kCTFontAttributeName

value:(id)helvetica

range:NSMakeRange(0, [stringlength])];

//字体样式 ,把helveticaBold 样式加到整个，string上

[string addAttribute:(id)kCTFontAttributeName

value:(id)helveticaBold

range:NSMakeRange(0, [stringlength])];

//颜色,此处为黑色，你可以自己改颜色，[UIColor redColor]

[string addAttribute:(id)kCTForegroundColorAttributeName

value:(id)[UIColorblackColor].CGColor

range:NSMakeRange(0, [stringlength])];

//创建文本对齐方式

CTTextAlignmentalignment = kCTJustifiedTextAlignment;//对齐方

CTParagraphStyleSettingalignmentStyle;

alignmentStyle.spec=kCTParagraphStyleSpecifierAlignment;

alignmentStyle.valueSize=sizeof(alignment);

alignmentStyle.value=&alignment;

//设置字体间距

long number =self.character;

CFNumberRefnum = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt8Type, &number);

[string addAttribute:(id)kCTKernAttributeNamevalue:(id)numrange:NSMakeRange(0, [stringlength])];

CFRelease(num);

//创建文本, 行间距

CGFloat lineSpace=self.line;//间距数据

CTParagraphStyleSettinglineSpaceStyle;

lineSpaceStyle.spec=kCTParagraphStyleSpecifierLineSpacing;

lineSpaceStyle.valueSize=sizeof(lineSpace);

lineSpaceStyle.value=&lineSpace;

//设置段落间距

CGFloat paragraph =self.paragraph;

CTParagraphStyleSettingparagraphStyle;

paragraphStyle.spec= kCTParagraphStyleSpecifierParagraphSpacing;

paragraphStyle.valueSize =sizeof(CGFloat);

paragraphStyle.value = &paragraph;

//创建样式数组

CTParagraphStyleSettingsettings[]={

alignmentStyle,lineSpaceStyle,paragraphStyle

};

//设置样式

CTParagraphStyleRef paragraphStyle1 =CTParagraphStyleCreate(settings,sizeof(settings));

//给字符串添加样式attribute

[string addAttribute:(id)kCTParagraphStyleAttributeName

value:(id)paragraphStyle1

range:NSMakeRange(0, [stringlength])];

// layout master

CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)string);

//计算文本绘制size ，这里300是文字宽度，你可以自己更改为247，但是要记得，在height 方法里的这个位置，也改为247

CGSizetmpSize = CTFramesetterSuggestFrameSizeWithConstraints(framesetter, CFRangeMake(0,0),NULL, CGSizeMake(300,MAXFLOAT),NULL);

//创建textBoxSize以设置view的frame

CGSize textBoxSize =CGSizeMake((int)tmpSize.width +1, (int)tmpSize.height +1);

// NSLog(@"textBoxSize0 == %f,%f,%f",textBoxSize.width,textBoxSize.height,textBoxSize.width / textBoxSize.height);

self.frame =CGRectMake(0,0, textBoxSize.width , textBoxSize.height);

[string release];

//- (void)drawRect:(CGRect)rect;代码

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);

// NSLog(@"textBoxSize1 == %f,%f",self.frame.size.width,self.frame.size.height);

// flip the coordinate system

CGContextRefcontext = UIGraphicsGetCurrentContext();

CGContextClearRect(context,self.frame);

CGContextSetFillColorWithColor(context, [[UIColor whiteColor]CGColor]);

CGContextFillRect(context,CGRectMake(0,0, 320,self.frame.size.height));

CGContextSetTextMatrix(context, CGAffineTransformIdentity);

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

CGContextScaleCTM(context,1.0, -1.0);

// draw

CTFrameDraw(leftFrame, context);

// cleanup

CGPathRelease(leftColumnPath);

CFRelease(framesetter);

//CFRelease(helvetica);

// CFRelease(helveticaBold);

UIGraphicsPushContext(context);

}

#pragma mark - 计算高度的方法

//这个方法，剪切到你要用的那个类里面，就ok了

// 或者，就放这里，但改成实例方法，+(CGSize)height:^^^^^^^^^

-(CGSize)height:(NSString *)text Font:(CGFloat)font Character:(CGFloat)character Line:(CGFloat)line Pragraph:(CGFloat)pragraph

{

//创建AttributeStringfdsa

NSMutableAttributedString*string = [[NSMutableAttributedStringalloc]

initWithString:text];

//创建字体以及字体大小

CTFontRef helvetica =CTFontCreateWithName(CFSTR("Helvetica"), font,NULL);

CTFontRef helveticaBold =CTFontCreateWithName(CFSTR("Helvetica"), font,NULL);

//添加字体目标字符串从下标0开始到字符串结尾

[string addAttribute:(id)kCTFontAttributeName

value:(id)helvetica

range:NSMakeRange(0, [stringlength])];

//添加字体目标字符串从下标0开始，截止到4个单位的长度

[string addAttribute:(id)kCTFontAttributeName

value:(id)helveticaBold

range:NSMakeRange(0, [stringlength])];

[string addAttribute:(id)kCTForegroundColorAttributeName

value:(id)[UIColorwhiteColor].CGColor

range:NSMakeRange(0, [stringlength])];

CTTextAlignmentalignment = kCTJustifiedTextAlignment;//这种对齐方式会自动调整，使左右始终对齐

CTParagraphStyleSettingalignmentStyle;

alignmentStyle.spec=kCTParagraphStyleSpecifierAlignment;//指定为对齐属性

alignmentStyle.valueSize=sizeof(alignment);

alignmentStyle.value=&alignment;

//设置字体间距

long number = character;

CFNumberRefnum = CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt8Type, &number);

[string addAttribute:(id)kCTKernAttributeNamevalue:(id)numrange:NSMakeRange(0, [stringlength])];

CFRelease(num);

//创建文本行间距

CGFloat lineSpace=line;//间距数据

CTParagraphStyleSettinglineSpaceStyle;

lineSpaceStyle.spec=kCTParagraphStyleSpecifierLineSpacing;//指定为行间距属性

lineSpaceStyle.valueSize=sizeof(lineSpace);

lineSpaceStyle.value=&lineSpace;

//设置段落间距

CGFloat paragraph = pragraph;

CTParagraphStyleSettingparagraphStyle;

paragraphStyle.spec= kCTParagraphStyleSpecifierParagraphSpacing;

paragraphStyle.valueSize =sizeof(CGFloat);

paragraphStyle.value = &paragraph;

//创建样式数组

CTParagraphStyleSettingsettings[]={

alignmentStyle,lineSpaceStyle,paragraphStyle

};

//设置样式

CTParagraphStyleRef paragraphStyle1 =CTParagraphStyleCreate(settings,sizeof(settings));

//给字符串添加样式attribute

[string addAttribute:(id)kCTParagraphStyleAttributeName

value:(id)paragraphStyle1

range:NSMakeRange(0, [stringlength])];

// layout master

CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((CFAttributedStringRef)string);

//计算文本绘制size

CGSizetmpSize = CTFramesetterSuggestFrameSizeWithConstraints(framesetter, CFRangeMake(0,0),NULL, CGSizeMake(300,MAXFLOAT),NULL);

//创建textBoxSize以设置view的frame

CGSize textBoxSize =CGSizeMake((int)tmpSize.width +1, (int)tmpSize.height +1);

[string release];

return textBoxSize;

}

@end

3. 注意上面的Myview 默认要绘制的文字宽度是 300，如果你想要的文字宽度是 200，请你去改代码，

//计算文本绘制size ，这里300是文字宽度，你可以自己更改为200，但是要记得，在height 方法里的这个位置，也改为200，这个很重要

CGSize tmpSize =CTFramesetterSuggestFrameSizeWithConstraints(framesetter,CFRangeMake(0,0), NULL, CGSizeMake(300, MAXFLOAT), NULL);

把这个MyView 加入到你的工程里面，就完成了工作的80%了，接下来，更简单，

4 看完下面的，你就会了

我们知道，不同文字他的高度，是不确定的，如果超过 height 460，548,那么你一个屏幕是显示不下的

这时候，我们怎么用这个Myview呢

请看下面的具体用法，

@property(nonatomic,assign)CGSizesize;

@property(nonatomic,retain)NSString*text;

- (void)viewDidLoad

{

[super viewDidLoad];

self.text = @"";你自己赋值，

self.size= [self height:self.text Font:15 Character:4 Line:10 Pragraph:20]; //必须先计算高度

NSLog(@"width:%f, height:%f",self.size.width,self.size.height);

}

//在下面这个方法中的用法，

-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

Myview *myview = [[Myviewalloc]initWithFrame:CGRectMake(0,0, self.size.width, self.size.height)];//知道为什么，先算高度了吧

myview.text =self.text;

myview.font =15;

myview.line =10;

myview.paragraph =20;

myview.character =4; //这些值比须和，height方法里传的5个参数一一对 //应相等。

UIView *v1 = [[UIViewalloc]initWithFrame:CGRectMake(8,10, 304,self.size.height)]; //这里并不是多此一举，不信你自己去掉试试，你会发 //现，你画的文字，是从（0，y，width，height）这里开始画的，和里myview的 //CGRectMake(x,y,300,height)x,y无关。

[v1 addSubview:myview];

[cell addSubview:v1];

当然cell的高度，也是我们算好了的

-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath

{

return self.size.height+20;

}

5 到此，你应该已经会了，如果关键的第4步，你没看懂，那么请看下篇，我贴出了，使用Myview的详细全部代码，你直接使用之后就明白了。

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