Question

我使用以下代码从字符串长度计算标签的高度。我使用的是xcode 5.0，它在iOS 6模拟器中运行良好，但在iOS 7中效果不佳。

NSString* str = [[array objectAtIndex:i]valueForKey:@"comment"];

CGSize size = [className sizeWithFont:[UIFont systemFontOfSize:15]   
 constrainedToSize:CGSizeMake(300, MAXFLOAT) lineBreakMode:UILineBreakModeWordWrap];

Height_1 = size.height;

如果iOS 7有任何解决方案，那么请帮忙。在此先感谢

Answer 1

这里有一个我用来计算iOS 6和iOS 7高度的解决方案，我已经通过了一些参数来使它可以重复使用。

#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)

/**
*  This method is used to calculate height of text given which fits in specific width having    font provided
*
*  @param text       Text to calculate height of
*  @param widthValue Width of container
*  @param font       Font size of text
*
*  @return Height required to fit given text in container
*/

+ (CGFloat)findHeightForText:(NSString *)text havingWidth:(CGFloat)widthValue andFont:(UIFont *)font
{
    CGFloat result = font.pointSize + 4;
    if (text)
    {
        CGSize textSize = { widthValue, CGFLOAT_MAX };       //Width and height of text area
        CGSize size;
        if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0"))
        {
            //iOS 7
            CGRect frame = [text boundingRectWithSize:textSize
                                          options:NSStringDrawingUsesLineFragmentOrigin
                                       attributes:@{ NSFontAttributeName:font }
                                          context:nil];
            size = CGSizeMake(frame.size.width, frame.size.height+1);
        }
        else
        {
            //iOS 6.0
            size = [text sizeWithFont:font constrainedToSize:textSize lineBreakMode:NSLineBreakByWordWrapping];
        }
        result = MAX(size.height, result); //At least one row
    }
    return result;
}

希望这会有所帮助，是的，任何建议都表示赞赏。快乐编码：）

对于iOS 7及以上版本，请使用以下方法。

+ (CGSize)findHeightForText:(NSString *)text havingWidth:(CGFloat)widthValue andFont:(UIFont *)font {
    CGSize size = CGSizeZero;
    if (text) {
        //iOS 7
        CGRect frame = [text boundingRectWithSize:CGSizeMake(widthValue, CGFLOAT_MAX) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{ NSFontAttributeName:font } context:nil];
        size = CGSizeMake(frame.size.width, frame.size.height + 1);
    }
    return size;
}

Answer 2

尝试使用此

#define FONT_SIZE 15.0f
#define CELL_CONTENT_WIDTH 320.0f
#define CELL_CONTENT_MARGIN 20.0f


NSString *text;
CGSize constraint;
CGSize size;
CGFloat height;

text = [[array objectAtIndex:i]valueForKey:@"comment"];
constraint = CGSizeMake(CELL_CONTENT_WIDTH - (CELL_CONTENT_MARGIN * 2), 20000.0f);

CGRect textRect = [text boundingRectWithSize:constraint
                                    options:NSStringDrawingUsesLineFragmentOrigin
                                    attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:FONT_SIZE]}
                                    context:nil];

size = textRect.size;


height = size.height;

Answer 3

sizeWithFont

已弃用。使用

[string sizeWithAttributes:@{NSFontAttributeName:[UIFont systemFontOfSize:15]}];

代替

Answer 4

使用以下代码获取标签的高度

CGSize szMaxCell = CGSizeMake(220, 2999);
UIFont *font = [UIFont systemFontOfSize:14.0f];    // whatever font you're using to display
CGSize szCell = [yourString sizeWithFont:font constrainedToSize:szMaxCell lineBreakMode:NSLineBreakByWordWrapping];

在iOS 7中获取NSString高度

4 个答案: