IOS界面开发之UILabel

这里记录了UILabel的一些常见操作，和关闭当前界面的代码。

//
//  LabelViewController.m
//  UIViewDemo
//
//  Created by dcr on 2016/12/16.
//  Copyright © 2016年 All rights reserved.
//

#import "LabelViewController.h"

@interface LabelViewController ()

@end

@implementation LabelViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    self.view.backgroundColor = [UIColor greenColor];
    CGRect rect = [[UIApplication sharedApplication] statusBarFrame];
    UIButton *btnImageView = [UIButton buttonWithType:UIButtonTypeSystem];
    btnImageView.frame = CGRectMake(0, rect.size.height, 100, 40);
    btnImageView.backgroundColor = [UIColor whiteColor];
    btnImageView.titleLabel.font = [UIFont systemFontOfSize:16];
    [btnImageView setTitle:@"返回" forState:UIControlStateNormal];
    [btnImageView setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    [btnImageView addTarget:self action:@selector(btnBack) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:btnImageView];
    
    //文本标签
    UILabel *label = [[UILabel alloc] init];
    label.frame = CGRectMake(10, 100, 250, 200);
    label.backgroundColor = [UIColor yellowColor];
    //设置文本
    label.text = @"学习IOS记录，Foundation框架学习，由于Swift语言一直有在更新，且IOS开发中有很多库都是使用Objective-C语言的，所以Objective-C的学习还是很有必要的，下面是对NSString学习的一些记录。Foundation框架学习之NSArray和NSMutableArray";
    //文字布局模式
    label.textAlignment = NSTextAlignmentCenter;
    //文字颜色，可自定义颜色值
    label.textColor = [UIColor colorWithRed:1 green:0 blue:0 alpha:0.5];
    //label这透明
    //label.alpha = 0.5;
    //设置字体
    //label.font = [UIFont systemFontOfSize:20];
    //加粗
    //label.font = [UIFont boldSystemFontOfSize:20];
    //倾斜，只对英文有效
    label.font = [UIFont italicSystemFontOfSize:20];
    //遍历所有字体
    for(NSString *name in [UIFont familyNames]){
        NSLog(@"font family name = %@", name);
    }
    //设置系统支持的任意字体
    label.font = [UIFont fontWithName:@"Times New Roman" size:25];
    //设置阴影
    //label.shadowColor = [UIColor redColor];
    //label.shadowOffset = CGSizeMake(2, 2);
    
    //换行自适应大小
    //换行模式 一般选择字符换行，还有单词NSLineBreakByWordWrapping
    label.lineBreakMode = NSLineBreakByCharWrapping;
    //显示行数  0或者-1表示不限制行数
    label.numberOfLines = 0;
    
    //根据字符串的大小计算Label的大小
    CGSize size = [label.text sizeWithFont:label.font constrainedToSize:CGSizeMake(250, 10000) lineBreakMode:NSLineBreakByWordWrapping];
    //根据字符区域大小重新设置label的大小
    label.frame = CGRectMake(label.frame.origin.x, label.frame.origin.y, size.width, size.height);
    [self.view addSubview:label];
}

- (void)btnBack{
    //关闭当前窗口
    [self dismissViewControllerAnimated:true completion:^{
        NSLog(@"LabelViewController back completion");
    }];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/

@end

完整示例代码下载：http://download.csdn.net/detail/deng0zhaotai/9715127