iOS应用中UILabel文字显示效果的常用设置总结

UILabel* label = [[UILabel alloc] initWithFrame:self.view.bounds];

label.text = @"This is a UILabel Demo,";

label.font = [UIFont fontWithName:@"Arial" size:35];

label.textColor = [UIColor yellowColor];

label.textAlignment = UITextAlignmentCenter;

label.backgroundColor = [UIColor blueColor];

label.lineBreakMode = UILineBreakModeWordWrap;

label.numberOfLines = 0;

[label sizeToFit];

CGSize size = [label.text sizeWithFont:label.font constrainedToSize:self.view.bounds.size lineBreakMode:label.lineBreakMode];

CGRect rect = label.frame;

rect.size.height = size.height;

label.frame = rect; 

typedef enum {
   UILineBreakModeWordWrap = 0,      // 以空格为边界，保留整个单词
   UILineBreakModeCharacterWrap,     // 保留整个字符
   UILineBreakModeClip,                     // 到边界为止
   UILineBreakModeHeadTruncation,    // 省略开始，以……代替
   UILineBreakModeTailTruncation,      // 省略结尾，以……代替
   UILineBreakModeMiddleTruncation,  // 省略中间，以……代替，多行时作用于最后一行 
} UILineBreakMode;

//这个frame是初设的，没关系，后面还会重新设置其size。
    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0,0,0,0)];
    label.numberOfLines = 0;
    label.backgroundColor = [UIColor clearColor];
   
    NSDictionary *attributes = @{NSFontAttributeName:[UIFont systemFontOfSize:20],};
   
    NSString *str = @"abcdefg你上课可是你的拿到了";
    CGSize textSize = [str boundingRectWithSize:CGSizeMake(100, 100) options:NSStringDrawingTruncatesLastVisibleLine attributes:attributes context:nil].size;;
   
    [label setFrame:CGRectMake(100, 100, textSize.width, textSize.height)];
    label.textColor = [UIColor greenColor];
    label.text = str;
    [self.view addSubview:label];