[iOS基础控件

A.基本使用

1.概念

iOS内置的浏览器控件

Safari浏览器就是通过UIWebView实现的

2.用途：制作简易浏览器

（1）基本请求

创建请求

加载请求

（2）代理监听webView加载，例如提示正在加载

（3）前进、后退

使用NavigationController，在底部加上导航栏（勾选showToolBar），加上回退和前进按钮

（4）给顶部导航栏加上地址栏

UISearchBar

代理监听“搜索”按钮，提取地址栏文本

 1 //
 2 //  ViewController.m
 3 //  UIWebViewdDemo
 4 //
 5 //  Created by hellovoidworld on 15/1/30.
 6 //  Copyright (c) 2015年 hellovoidworld. All rights reserved.
 7 //
 8 
 9 #import "ViewController.h"
10 
11 @interface ViewController () <UISearchBarDelegate, UIWebViewDelegate>
12 
13 @property (weak, nonatomic) IBOutlet UIWebView *webView;
14 
15 @property (weak, nonatomic) IBOutlet UIBarButtonItem *backButton;
16 @property (weak, nonatomic) IBOutlet UIBarButtonItem *forwardButton;
17 - (IBAction)back:(UIBarButtonItem *)sender;
18 - (IBAction)forward:(UIBarButtonItem *)sender;
19 
20 @end
21 
22 @implementation ViewController
23 
24 - (void)viewDidLoad {
25     [super viewDidLoad];
26     // Do any additional setup after loading the view, typically from a nib.
27    
28     // 创建一个搜索栏
29     UISearchBar *searchBar = [[UISearchBar alloc] init];
30     searchBar.frame = CGRectMake(0, 0, 300, 40);
31     searchBar.delegate = self;
32    
33     self.navigationItem.titleView = searchBar;
34    
35     self.webView.delegate = self;
36 }
37 
38 
39 
40 - (IBAction)back:(UIBarButtonItem *)sender {
41     NSLog(@"后退");
42     [self.webView goBack];
43 }
44 
45 - (IBAction)forward:(UIBarButtonItem *)sender {
46     NSLog(@"前进");
47     [self.webView goForward];
48 }
49 
50 #pragma mark - UIWebViewDelegate
51 - (void)webViewDidStartLoad:(UIWebView *)webView {
52     NSLog(@"开始加载");
53 }
54 
55 - (void)webViewDidFinishLoad:(UIWebView *)webView {
56     NSLog(@"完成加载");
57 
58     // 设置后退、前进按钮
59     if ([self.webView canGoBack]) {
60         self.backButton.enabled = YES;
61     } else {
62         self.backButton.enabled = NO;
63     }
64    
65     if ([self.webView canGoForward]) {
66         self.forwardButton.enabled = YES;
67     } else {
68         self.forwardButton.enabled = NO;
69     }
70 }
71 
72 #pragma mark - UISearchBarDelegate
73 /** 点击搜索按钮（虚拟键盘上) */
74 - (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar {
75     NSString *str = searchBar.text;
76     NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"http://%@", str]];
77     NSURLRequest *request = [NSURLRequest requestWithURL:url];
78    
79     [self.webView loadRequest:request];
80 }
81  
82 @end

3.加载本地资源

html、txt、doc、ppt、MP4、pdf

直接请求即可

4.自动识别电话、邮箱、地址

// 识别所有类型的数据

self.webView.dataDetectorTypes = UIDataDetectorTypeAll;

B.其他用途

1.OC执行javascript

1 /** 运行js代码 */
2 - (IBAction)runJs {
3     NSString *str = @"alert('hello, world!');";
4     [self.webView stringByEvaluatingJavaScriptFromString:str];
5 }

2.javascript调用OC

在javascript中发送网页请求，使用OC截取，根据内容判断调用相应方法

这里使用js代码呼出相册选择:

网页 & js 代码：

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 7 <title>运行OC代码</title>
 8 </head>
 9 <body>
10  
11      <script type="text/javascript">
12           function runOC() {
13                window.location.href="ios://openAlbum";
14           }
15      </script>
16  
17      <input type="button" value="运行OC代码" onclick="runOC();" />
18    
19 </body>
20 </html>

OC代码：

 1 /** webView发送请求之前都会调用，可以拦截请求，选择加载（返回YES）还是不加载（返回NO）*/
 2 - (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
 3    
 4     // 拦截请求
 5     NSString *urlStr = request.URL.absoluteString;
 6     NSRange range = [urlStr rangeOfString:@"ios://"];
 7    
 8     // 如果是ios请求
 9     if (range.length != 0) {
10         // 方法名
11         NSString *method = [urlStr substringFromIndex:range.location + range.length];
12        
13         // 包装SEL
14         SEL selector = NSSelectorFromString(method);
15        
16         // 执行方法
17         [self performSelector:selector withObject:nil];
18     }
19    
20     return YES;
21 }
22 
23 /** 打开相册 */
24 - (void) openAlbum {
25     // 创建一个相片选择控制器
26     UIImagePickerController *imagePC = [[UIImagePickerController alloc] init];
27     [imagePC setSourceType:UIImagePickerControllerSourceTypePhotoLibrary]; // 使用相册来源
28    
29     [self presentViewController:imagePC animated:YES completion:^{
30         NSLog(@"呼出相册");
31     }];
32 }