製作最大寬度的可變尺寸UILabel

Question

我用以下代碼製作了可變尺寸UILabel。
但我想將最大寬度設置爲label。
你有什麼想法嗎？

- (void)viewDidLoad { 
    CGSize size = [self labelFrameWithString:@"test text"]; 
    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, size.width. size.height]; 
    label.text = @"test text"; 
} 

- (CGSize)labelFrameWithString:(NSString *)string { 
    CGRect frame = [string boundingRectWithSize:CGSizeZero 
             options:(NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingTruncatesLastVisibleLine) 
            attributes:[NSDictionary dictionaryWithObject:[UIFont systemFontOfSize:16] forKey:NSFontAttributeName] 
             context:nil]; 

    return frame.size; 
} 

Answer 1

你試過傳遞一個約束CGSize而不是CGSizeZero嗎？

CGSize constraint = CGSizeMake(your_max_width ,NSUIntegerMax); 
CGRect frame = [string boundingRectWithSize:constraint 
            options:(NSStringDrawingUsesLineFragmentOrigin | NSStringDrawingTruncatesLastVisibleLine) 
           attributes:[NSDictionary dictionaryWithObject:[UIFont systemFontOfSize:16] forKey:NSFontAttributeName] 
            context:nil];