UI控件之UILable

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

　　//如何计算文本在一定情况下的具体高度和宽度

    //size:计算的参考尺寸，必须高度或者宽度确定

    NSString *text = @"The UIViewController class provides the infrastructure for managing the views of your iOS apps";

    //指定计算文本宽高时，所用的字体和字号

    NSDictionary *attrDic = @{NSFontAttributeName:[UIFont systemFontOfSize:20]};

    CGSize realSize = [text boundingRectWithSize:CGSizeMake(self.view.bounds.size.width - 100, 3000) options:NSStringDrawingUsesLineFragmentOrigin attributes:attrDic context:nil].size;

　　//创建
    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(50, 50, self.view.bounds.size.width - 100, realSize.height)];
    
    //设置显示的内容
    label.text = text;
    
    //设置字体颜色
    label.textColor = [UIColor orangeColor];
    //设置字体和字号
    label.font = [UIFont systemFontOfSize:20];
    //设置多行显示 0表示自动换行
    label.numberOfLines = 0;
    //设置换行方式，Word表示按单词换行，char按字符换行
    label.lineBreakMode = NSLineBreakByWordWrapping;
    //设置对齐方式
    label.textAlignment = NSTextAlignmentLeft;
    //添加到界面上
    [self.view addSubview:label];
    
    //设置阴影 UIView的方法
    label.layer.shadowColor = [UIColor blueColor].CGColor;
　　//偏移值
    label.layer.shadowOffset = CGSizeMake(5, 5);
    label.layer.shadowRadius = 5;
    label.layer.shadowOpacity = 1;

    
}