iOS界面编程－UILabel

UILabel文本
UILabel *label = [[UILabel
alloc] initWithFrame:CGRectMake(20,
150, self.view.bounds.size.width-40,
144)]; //初始化创建UILabel
[self.view
addSubview:label];
label.backgroundColor = [UIColor
whiteColor];//设置label背景颜色
label.textColor = [UIColor
greenColor];//设置label文字颜色
label.numberOfLines =
0;//行数为0代表不限制行数，默认为1
label.font = [UIFont
systemFontOfSize:16.f];//文字字体及大小，这里默认系统字体
label.textAlignment =
NSTextAlignmentJustified;//文字对齐方式
label.lineBreakMode =
NSLineBreakByTruncatingMiddle;//换行模式，可以根据字符，单词
label.highlighted =
YES;//是否高亮
label.highlightedTextColor = [UIColor
redColor];
label.shadowOffset =
CGSizeMake(10,
10);//文字阴影大小
label.shadowColor = [UIColor
blackColor];//阴影颜色

label.text =
@"this is a label!this is a label!this this this is a label!this is a label!this is a label!this is a label!this this this is a label!this is a label!!this this this is a label!this is a label!this is a label!thi";//label的文字

CGSize textSize = [label.text
boundingRectWithSize:CGSizeMake(label.frame.size.width,
CGFLOAT_MAX) options:NSStringDrawingUsesFontLeading|NSStringDrawingUsesLineFragmentOrigin
attributes:@{NSFontAttributeName: [UIFont
systemFontOfSize:16],
} context:nil].size;//设置label大小可以随着内容的多少进行变化。
label.frame = CGRectMake(20, label.frame.origin.y,
textSize.width, textSize.height);

CGSize textSize = [label.text boundingRectWithSize:CGSizeMake(label.frame.size.width, CGFLOAT_MAX) options:NSStringDrawingUsesFontLeading|NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName: [UIFont systemFontOfSize:16], } context:nil].size;

上面代码比较重要在动态计算label所占大小时，可以用到。