ios - NSString drawInRect :withAttributes: is not drawing text with greater width than the rect in iOS 7. 0.3

Question

我正在尝试在我的应用程序中生成一个 pdf。为了绘制字符串，我使用 boundingRectWithSize 计算该字符串的边界矩形的大小，然后在该大小的矩形内绘制字符串。

该代码在 iOS 7.1 及更高版本中运行良好，但在 iOS 7.0.3 中，如果文本的宽度大于矩形的宽度 (400)，则根本不会绘制文本。根据 Apple 的文档，如果字符串不适合矩形，则该字符串应该换行并剪裁，这在 iOS 7.1 及更高版本中发生，但在 iOS 7.0.3 中不会发生。

这是我的代码片段:

-(void)drawText:(NSString *)string
{
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [UIColor blackColor].CGColor);

    NSDictionary *attrsDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
 myFontForContentBold, NSFontAttributeName,
 [NSNumber numberWithFloat:1.0], NSBaselineOffsetAttributeName, nil];

    CGRect textRect = [string boundingRectWithSize:CGSizeMake(400, CGFLOAT_MAX) options:NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading attributes:attributes context:nil]
textRect = CGRectMake(130, 80, 400, textRect.size.height);

    [string drawInRect:textRect withAttributes:attrsDictionary];
}

我无法弄清楚可能是什么问题。请帮忙。

Answer 1

试试这个:

-(void)drawText:(NSString *)string {
// this method must be called after a valid graphic context 
// is configured, it can be called in drawRect:, or a bitmap or pdf context is configured.
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [UIColor blackColor].CGColor);

    NSDictionary *attrsDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
                                     myFontForContentBold, NSFontAttributeName,
                                     [NSNumber numberWithFloat:1.0], NSBaselineOffsetAttributeName, nil];
    NSAttributedString *richText = [[NSAttributedString alloc] initWithString:string attributes:attrsDictionary];

    CGRect textRect = [richText boundingRectWithSize:CGSizeMake(400, CGFLOAT_MAX)
                                      options:NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingUsesFontLeading
                                      context:nil];

    textRect = CGRectMake(130, 80, 400, textRect.size.height);

    [richText drawInRect:textRect];
}

如果您需要绘制大块文本，请考虑 Text Kit。

Text Kit 方法:

- (void)drawAddressList:(NSArray *)list atPoint:(CGPoint)point {
    NSTextStorage *textStorage = [[NSTextStorage alloc] init];
    NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
    NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:CGSizeMake(400.0f, FLT_MAX)];
    [textStorage addLayoutManager:layoutManager];
    [layoutManager addTextContainer:textContainer];
    textContainer.lineFragmentPadding = 0.0f;

    NSDictionary *attributes = @{NSFontAttributeName:[UIFont preferredFontForTextStyle:UIFontTextStyleBody]};
    // it's a simple attributes for illustration
    for (NSString *address in list) {
        NSString *buffer = [NSString stringWithFormat:@"%@\n", address];
        [textStorage appendAttributedString:[[NSAttributedString alloc] initWithString:buffer attributes:attributes]];
    }

    [layoutManager ensureLayoutForTextContainer:textContainer];
    CGRect rect = [layoutManager usedRectForTextContainer:textContainer];
    rect.size.width = 400.0f;
    rect.size.height = ceilf(rect.size.height);
    rect.origin = point; // this is the frame needed to draw the address list

    [layoutManager drawGlyphsForGlyphRange:NSMakeRange(0, textStorage.length) atPoint:point];
}