IOS-将长文字转化成图片方法

我们在看微博时，会看到一些长图片上的显示文章，现在就介绍下如何实现。分析下还是很简单的，总结如下：1、计算文字区域的高 2、利用UIGraphics图形上下文方法来实现 3、验证方法：UIImageWriteToSavedPhotosAlbum，在本地相册中查看成功与否。

-(UIImage *)imageFromText:(NSArray*) arrContent withFont: (CGFloat)fontSize

{

// set the font type and size

UIFont *font = [UIFontsystemFontOfSize:fontSize];

NSMutableArray *arrHeight = [[NSMutableArrayalloc] initWithCapacity:arrContent.count];

CGFloat fHeight = 0.0f;

for (NSString *sContent in arrContent) {

CGSize stringSize = [sContent sizeWithFont:font constrainedToSize:CGSizeMake(CONTENT_MAX_WIDTH, 10000) lineBreakMode:UILineBreakModeWordWrap];

[arrHeight addObject:[NSNumbernumberWithFloat:stringSize.height]];

fHeight += stringSize.height;

}

CGSize newSize = CGSizeMake(CONTENT_MAX_WIDTH+20, fHeight+50);

UIGraphicsBeginImageContextWithOptions(newSize,NO,0.0);

CGContextRef ctx = UIGraphicsGetCurrentContext();

CGContextSetCharacterSpacing(ctx, 10);

CGContextSetTextDrawingMode (ctx, kCGTextFillStroke);

CGContextSetRGBFillColor (ctx, 0.1, 0.2, 0.3, 1); // 6

CGContextSetRGBStrokeColor (ctx, 0, 0, 0, 1);

int nIndex = 0;

CGFloat fPosY = 20.0f;

for (NSString *sContent in arrContent) {

NSNumber *numHeight = [arrHeight objectAtIndex:nIndex];

CGRect rect = CGRectMake(10, fPosY, CONTENT_MAX_WIDTH , [numHeight floatValue]);

[sContent drawInRect:rect withFont:font lineBreakMode:UILineBreakModeWordWrapalignment:UITextAlignmentLeft];

fPosY += [numHeight floatValue];

nIndex++;

}

// transfer image

UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);

return image;

}