外贸网站制作哪家快/免费发布产品的网站
转载于：http://ikevin.tw/209
在iOS中，要計算文字區域的大小，說實在的是有一點麻煩，因為還沒繪製文字之前，是很難得到文字的區域大小的，所以我們通常的做法是：
1.先開一個極大的區域，固定寬度，然後文字往下排。
2.設定文字大小及行距。
3.取得行數。
4.取得文字區域高度＝行數X(文字大小+行距)-行距。 //註：最後一行沒有行距
5.開一個繪圖（context）大小（文字區域寬高）。
6.開始繪圖。
7.取得繪圖內容（UIImage）。
請參考以下範例
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView
{UIView *view=[[UIView alloc] initWithFrame:CGRectMake(0, 20, 768, 1004)];self.view=view;[self drawTexttoImage];
}-(void)drawTexttoImage{CGRect colRect=CGRectMake(0, 0, 354, 32767); CGMutablePathRef path = CGPathCreateMutable();CGPathAddRect(path, NULL, colRect);NSMutableAttributedString *string = [[NSMutableAttributedString alloc] initWithString:@"可以放多一點文字試試看"];//設定字型及大小CTFontRef fontRef = CTFontCreateWithName((CFStringRef)@"STHeitiTC-Medium",24.0f, NULL);[string addAttribute:(NSString *)kCTFontAttributeName value:(__bridge id)fontRef range:NSMakeRange(0, [string length])];//設定對齊方式CTTextAlignment alignment = kCTJustifiedTextAlignment;CTParagraphStyleSetting alignmentStyle;alignmentStyle.spec=kCTParagraphStyleSpecifierAlignment;alignmentStyle.valueSize=sizeof(alignment);alignmentStyle.value=&alignment;//設定行距CGFloat lineSpace=12.0f;CTParagraphStyleSetting lineSpaceStyle;lineSpaceStyle.spec=kCTParagraphStyleSpecifierLineSpacing;lineSpaceStyle.valueSize=sizeof(24.0f);lineSpaceStyle.value=&lineSpace;CTParagraphStyleSetting settings[]={alignmentStyle,lineSpaceStyle};CTParagraphStyleRef paragraphStyle = CTParagraphStyleCreate(settings, sizeof(settings));//設定段落樣式[string addAttribute:(id)kCTParagraphStyleAttributeName value:(__bridge id)paragraphStyle range:NSMakeRange(0, [string length])];CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString((__bridge CFAttributedStringRef)string);CTFrameRef frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, [string length]), path, NULL);NSArray *lines = (__bridge NSArray *)CTFrameGetLines(frame);int area_h=[lines count]*(24+12)-12; //計算本文高度CGRect imageSize=CGRectMake(0, 0, 354, area_h);//設定繪圖區域UIGraphicsBeginImageContext(imageSize.size); CGContextRef context=UIGraphicsGetCurrentContext();CGContextSetTextMatrix(context, CGAffineTransformIdentity);CGContextTranslateCTM(context, 0, colRect.size.height);CGContextScaleCTM(context, 1.0, -1.0);CTFrameDraw(frame, context); CFRelease(path);CFRelease(framesetter);CFRelease(fontRef);//取出圖像及圖像尺寸[self setImage:UIGraphicsGetImageFromCurrentImageContext() size:imageSize.size];}
-(void)setImage:(UIImage *)img size:(CGSize)size{UIImageView *imageView=[[UIImageView alloc] initWithFrame:CGRectMake(0, 0, size.width,size.height)];[imageView setImage:img];[self.view addSubview:imageView];}