用CoreGraphics框架画文本的用户体验较UITextView的好。但是效率会比UITextView差，还有支持图片的功能设置大小时不是很好处理。
下面看一下画出来的富文本效果图：
screen
集成代码如下：
- (void)viewDidLoad {
[super viewDidLoad];
NSString *text = @"[健身]我下载demo啊test[大哭]lms在https://github.com/SoftProgramLX?tab=repositories测试[微笑]选打11111我的github";
LXRichTextView *view = [[LXRichTextView alloc] init];
view.text = text;
view.isUrl = YES;//设置为NO则不匹配链接。
view.backgroundColor = [UIColor greenColor];
view.font = [UIFont systemFontOfSize:18];
view.delegage = self;
view.urlDic = @{@"我的github": @"https://github.com/SoftProgramLX?tab=repositories", @"下载demo": @"https://github.com/SoftProgramLX/LXDrawTextView"};
[self.view addSubview:view];
view.frame = CGRectMake(20, 40, 300, [LXHelpClass calculateLabelighWithText:text withMaxSize:CGSizeMake(300, MAXFLOAT) withFont:18 withSpaceRH:0]);
}
- (void)richTextView:(LXRichTextView *)view touchBeginRun:(LXRichTextBaseRun *)run
{
NSLog(@"%@", run.originalText);
}
- view.urlDic属性的作用：设置文本中出现的这些文本当作超链接处理，将文本作为字典的key，相应的地址作为value。
- richTextView: touchBeginRun：这是点击了链接的触发方法，链接的地址是run.originalText。
核心代码如下：
- (void)drawRect:(CGRect)rect
{
//解析文本
_textAnalyzed = [self analyzeText:_text andIsUrl:self.isUrl];
//要绘制的文本
NSMutableAttributedString* attString = [[NSMutableAttributedString alloc] initWithString:self.textAnalyzed];
NSMutableParagraphStyle * paragraphStyle0 = [[NSMutableParagraphStyle alloc] init];
[paragraphStyle0 setLineBreakMode:NSLineBreakByCharWrapping];
[attString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle0 range:NSMakeRange(0, attString.length)];
// CTParagraphStyleSetting lineBreakMode;
// CTLineBreakMode lineBreak = kCTLineBreakByCharWrapping; //换行模式
// lineBreakMode.spec = kCTParagraphStyleSpecifierLineBreakMode;
// lineBreakMode.value = &lineBreak;
// lineBreakMode.valueSize = sizeof(CTLineBreakMode);
// CTParagraphStyleSetting settings[] = {lineBreakMode};
// CTParagraphStyleRef paragraphStyle = CTParagraphStyleCreate(settings, 1); //第二个参数为settings的长度
// [attString addAttribute:(NSString *)kCTParagraphStyleAttributeName
// value:(id)paragraphStyle
// range:NSMakeRange(0, attString.length)];
//设置字体
CTFontRef aFont = CTFontCreateWithName((__bridge CFStringRef)self.font.fontName, self.font.pointSize, NULL);
[attString addAttribute:(NSString*)kCTFontAttributeName value:(__bridge id)aFont range:NSMakeRange(0,attString.length)];
CFRelease(aFont);
//设置颜色
[attString addAttribute:(NSString *)kCTForegroundColorAttributeName value:(id)self.textColor.CGColor range:NSMakeRange(0,attString.length)];
//文本处理
for (LXRichTextBaseRun *textRun in self.richTextRunsArray)
{
[textRun replaceTextWithAttributedString:attString];
}
//绘图上下文
CGContextRef context = UIGraphicsGetCurrentContext();
CTParagraphStyleSetting lineBreakMode;
CTLineBreakMode lineBreak = kCTLineBreakByCharWrapping; //换行模式
lineBreakMode.spec = kCTParagraphStyleSpecifierLineBreakMode;
lineBreakMode.value = &lineBreak;
lineBreakMode.valueSize = sizeof(CTLineBreakMode);
CTParagraphStyleSetting settings[] = {lineBreakMode};
CTParagraphStyleRef paragraphStyle = CTParagraphStyleCreate(settings, 1); //第二个参数为settings的长度
[attString addAttribute:(NSString *)kCTParagraphStyleAttributeName
value:(id)paragraphStyle
range:NSMakeRange(0, attString.length)];
//修正坐标系
CGAffineTransform textTran = CGAffineTransformIdentity;
textTran = CGAffineTransformMakeTranslation(0.0, self.bounds.size.height);
textTran = CGAffineTransformScale(textTran, 1.0, -1.0);
CGContextConcatCTM(context, textTran);
//绘制
int lineCount = 0;
CFRange lineRange = CFRangeMake(0,0);
CTTypesetterRef typeSetter = CTTypesetterCreateWithAttributedString((__bridge CFAttributedStringRef)attString);
float drawLineX = 0;
float drawLineY = self.bounds.origin.y + self.bounds.size.height - self.font.ascender;
BOOL drawFlag = YES;
[self.richTextRunRectDic removeAllObjects];
while(drawFlag)
{
CFIndex testLineLength = CTTypesetterSuggestLineBreak(typeSetter,lineRange.location,self.bounds.size.width);
check: lineRange = CFRangeMake(lineRange.location,testLineLength);
CTLineRef line = CTTypesetterCreateLine(typeSetter,lineRange);
CFArrayRef runs = CTLineGetGlyphRuns(line);
//边界检查
CTRunRef lastRun = CFArrayGetValueAtIndex(runs, CFArrayGetCount(runs) - 1);
CGFloat lastRunAscent;
CGFloat laseRunDescent;
CGFloat lastRunWidth = CTRunGetTypographicBounds(lastRun, CFRangeMake(0,0), &lastRunAscent, &laseRunDescent, NULL);
CGFloat lastRunPointX = drawLineX + CTLineGetOffsetForStringIndex(line, CTRunGetStringRange(lastRun).location, NULL);
if ((lastRunWidth + lastRunPointX) > self.bounds.size.width)
{
if (testLineLength > 0) {
testLineLength--;
CFRelease(line);
goto check;
}
drawFlag = NO;
}
//绘制普通行元素
drawLineX = CTLineGetPenOffsetForFlush(line,0,self.bounds.size.width);
CGContextSetTextPosition(context,drawLineX,drawLineY);
CTLineDraw(line,context);
//绘制替换过的特殊文本单元
for (int i = 0; i < CFArrayGetCount(runs); i++)
{
CTRunRef run = CFArrayGetValueAtIndex(runs, i);
NSDictionary* attributes = (__bridge NSDictionary*)CTRunGetAttributes(run);
LXRichTextBaseRun *textRun = [attributes objectForKey:@"TQRichTextAttribute"];
if (textRun)
{
CGFloat runAscent,runDescent;
CGFloat runWidth = CTRunGetTypographicBounds(run, CFRangeMake(0,0), &runAscent, &runDescent, NULL);
CGFloat runHeight = runAscent + (-runDescent);
CGFloat runPointX = drawLineX + CTLineGetOffsetForStringIndex(line, CTRunGetStringRange(run).location, NULL);
CGFloat runPointY = drawLineY - (-runDescent);
CGRect runRect = CGRectMake(runPointX, runPointY, runWidth, runHeight);
BOOL isDraw = [textRun drawRunWithRect:runRect];
if (textRun.isResponseTouch)
{
if (isDraw)
{
[self.richTextRunRectDic setObject:textRun forKey:[NSValue valueWithCGRect:runRect]];
}
else
{
runRect = CTRunGetImageBounds(run, context, CFRangeMake(0, 0));
runRect.origin.x = runPointX;
[self.richTextRunRectDic setObject:textRun forKey:[NSValue valueWithCGRect:runRect]];
}
}
}
}
CFRelease(line);
if(lineRange.location + lineRange.length >= attString.length)
{
drawFlag = NO;
}
lineCount++;
drawLineY -= self.font.ascender + (- self.font.descender) + self.lineSpacing;
lineRange.location += lineRange.length;
}
CFRelease(typeSetter);
}
源码请点击github地址下载。
QQ:2239344645 我的github
