iPhone：如何理解文本是否适合标签

Question

使用 IOS 4，我想以编程方式了解给定文本是否适合某个 UILabel，我可以在不进行复杂计算的情况下获取该信息吗？如果不是，最基本的计算方法是什么？

Answer 1

您可以在 NSString 上调用 - (CGSize)sizeWithFont:(UIFont *)font 。

Answer 2

NSString 方法 sizeWithFont:contrainedToSize:lineBreakMode: 可以提供帮助。它会给你 CGSize 和计算出的字符串大小。只需将其与您的 UILabel.frame.size 进行比较即可。

Answer 3

要确定任何字体的任何标签的高度，您可以使用此函数

+(float)calculateHeightOfTextFromWidth:(NSString*)text:(UIFont*)withFont:(float)width:(UILineBreakMode)lineBreakMode;

+(float) calculateHeightOfTextFromWidth:(NSString*) text: (UIFont*)withFont: (float)width:(UILineBreakMode)lineBreakMode
{
if (([text length]>0))
{
    CGSize suggestedSize = [text sizeWithFont:withFont   constrainedToSize:CGSizeMake(width, FLT_MAX) lineBreakMode:lineBreakMode];
    return suggestedSize.height;
}
return 18;
}

这是一个了解此函数工作原理的示例

if (![isRateABusinessController length]) {

     companyNameLabel.text = [NSString stringWithFormat:@"%@",[allDetails objectForKey:@"CNAME"]];

     NSString *cAdd    = [NSString stringWithFormat:@"%@",[allDetails objectForKey:@"CADD"]];

    float height = [ConfirmationViewController calculateHeightOfTextFromWidth:cAdd :[UIFont fontWithName:@"Arial" size:14] :170 :UILineBreakModeWordWrap];

    addressLabel.text = [NSString stringWithFormat:@"%@",cAdd];

    if (height > 30) {
        CGRect rect = CGRectMake(addressLabel.frame.origin.x , addressLabel.frame.origin.y, addressLabel.frame.size.width, addressLabel.frame.size.height+12.0);
        addressLabel.frame = rect;
    }
}
else
{
    companyNameLabel.text = [NSString stringWithFormat:@"%@",[Utility selectedCompanyName]];

    NSString *cAdd    = [NSString stringWithFormat:@"%@",[Utility selectedCompanyFullAddress]];
   // NSString *star     = [NSString stringWithFormat:@"Rating: %@",ratingName];

    float height = [ConfirmationViewController calculateHeightOfTextFromWidth:cAdd :[UIFont fontWithName:@"Arial" size:14] :170 :UILineBreakModeWordWrap];

    addressLabel.text = [NSString stringWithFormat:@"%@",cAdd];

    if (height > 30) {
        CGRect rect = CGRectMake(addressLabel.frame.origin.x , addressLabel.frame.origin.y, addressLabel.frame.size.width, addressLabel.frame.size.height+12.0);

        addressLabel.frame = rect;
    }
}

}