iOS UI基础-15.0 UIWebView

2022-10-22 15:06:56

WebView介绍

知识点:

代码创建一个UIWebView
OC调用html的js
js页面调用OC

代码创建一个UIWebView

    // 1.webView

    UIWebView *webView = [[UIWebView alloc] init];

    webView.frame = self.view.bounds;

    webView.delegate = self;

    // 伸缩页面至填充整个webView

    webView.scalesPageToFit = YES;

    // 隐藏scrollView

    webView.scrollView.hidden = YES;

    [self.view addSubview:webView];

    // 2.加载网页

    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://m.dianping.com/tuan/deal/5501525"]];

    [webView loadRequest:request];

OC调用html的js

关键代码：

    //  删除底部的链接的JS

    [js1 appendString:@"var footer = document.getElementsByTagName('footer')[0];"];

    [js1 appendString:@"footer.parentNode.removeChild(footer);"];

    // OC中调用js

    [webView stringByEvaluatingJavaScriptFromString:js1];

完整示例

创建一个webView，实现UIWebViewDelegate代理，在页面加载完毕后，通过js删除相关的html代码。

#import "HMViewController.h"

@interface HMViewController () <UIWebViewDelegate>

@property (nonatomic, weak) UIActivityIndicatorView *loadingView;

@end

@implementation HMViewController

/**

 test.html存在于服务器，里面的html和js代码，我们是无法修改的

 如果test.html显示在手机端，把那个ul去掉

 */

- (void)viewDidLoad

{

    [super viewDidLoad];

    // 1.webView

    UIWebView *webView = [[UIWebView alloc] init];

    webView.frame = self.view.bounds;

    webView.delegate = self;

    // 伸缩页面至填充整个webView

    webView.scalesPageToFit = YES;

    // 隐藏scrollView

    webView.scrollView.hidden = YES;

    [self.view addSubview:webView];

    // 2.加载网页

    NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://m.dianping.com/tuan/deal/5501525"]];

    [webView loadRequest:request];

    // 3.创建一个加载蒙板

    UIActivityIndicatorView *loadingView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];

    [loadingView startAnimating];

    loadingView.center = CGPointMake(, );

    [self.view addSubview:loadingView];

    self.loadingView = loadingView;

}

// OC -> JS

// 在OC中调用JS

#pragma mark - UIWebViewDelegate

- (void)webViewDidFinishLoad:(UIWebView *)webView

{

    // 执行JS代码，将大众点评网页里面的多余的节点删掉

    NSMutableString *js1 = [NSMutableString string];

    // 0.删除顶部的导航条

    [js1 appendString:@"var header = document.getElementsByTagName('header')[0];"];

    [js1 appendString:@"header.parentNode.removeChild(header);"];

    // 1.删除底部的链接

    [js1 appendString:@"var footer = document.getElementsByTagName('footer')[0];"];

    [js1 appendString:@"footer.parentNode.removeChild(footer);"];

    // OC中调用js

    [webView stringByEvaluatingJavaScriptFromString:js1];

    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.25 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{

        NSMutableString *js2 = [NSMutableString string];

        // 2.删除浮动的广告

        [js2 appendString:@"var list = document.body.childNodes;"];

        [js2 appendString:@"var len = list.length;"];

        [js2 appendString:@"var banner = list[len - 1];"];

        [js2 appendString:@"banner.parentNode.removeChild(banner);"];

        [webView stringByEvaluatingJavaScriptFromString:js2];

        // 显示scrollView

        webView.scrollView.hidden = NO;

        // 删除圈圈

        [self.loadingView removeFromSuperview];

    });

}

@end

js页面调用OC

oc加载的页面中，url链接跳转及请求，都会被shouldStartLoadWithRequest这个代理方法拦截，因而，我们在这里做处理。

html页面和oc两方都协商好，使用一个头文件来定义一个url链接请求，如：

 // 调用OC中call方法

 window.location.href = 'hm://call';

hm:// 就是相应的头文件了。接着，通过截取字符串的方式，来判断头文件是“hm://”开头的就是请求oc代码

具体代码实现。

test.html

<!DOCTYPE html>

<html>

    <head lang="en">

        <meta charset="UTF-8">

    </head>

    <body>

        <div>

            <button onclick="fn_open_camera();">拍照</button>

        </div>

        <div>

            <button onclick="fn_call();">打电话</button>

        </div>

        <a href="http://www.baidu.com">百度</a>

        <script>

            function fn_call() {

                // 调用OC中call方法

                window.location.href = 'hm://call';

            }

        function fn_open_camera() {

            // 调用OC中openCamera方法

            window.location.href = 'hm://openCamera';

        }

        </script>

    </body>

</html>

oc相关代码

#import "HMViewController.h"

@interface HMViewController () <UIWebViewDelegate>

@end

@implementation HMViewController

- (void)viewDidLoad

{

    [super viewDidLoad];

    // 1.webView

    UIWebView *webView = [[UIWebView alloc] init];

    webView.frame = self.view.bounds;

    webView.delegate = self;

    [self.view addSubview:webView];

    // 2.加载网页

    NSURL *url = [[NSBundle mainBundle] URLForResource:@"test" withExtension:@"html"];

    NSURLRequest *request = [NSURLRequest requestWithURL:url];

    [webView loadRequest:request];

}

#pragma mark - UIWebViewDelegate

/**

 *  webView每当发送一个请求之前，都会先调用这个方法（能拦截所有请求）

 */

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType

{

    NSString *url = request.URL.absoluteString;

    NSRange range = [url rangeOfString:@"hm://"];

    NSUInteger loc = range.location;

    if (loc != NSNotFound) { // url的协议头是hm

        // 方法名

        NSString *method = [url substringFromIndex:loc + range.length];

        // 转成SEL

        SEL sel = NSSelectorFromString(method);

        [self performSelector:sel withObject:nil];

    }

    return YES;

}

/**

 *  打电话

 */

- (void)call

{

    NSLog(@"call----");

}

/**

 *  打开照相机

 */

- (void)openCamera

{

    NSLog(@"openCamera----");

}

@end

上面这样就实现了，点击拍照和打开照相机，都会调用oc代码，而点击百度，则跳到百度的页面。

网易新闻详情

#import "HMViewController.h"

@interface HMViewController ()

@end

@implementation HMViewController

- (void)viewDidLoad

{

    [super viewDidLoad];

    // 1.url

    // http://c.m.163.com/nc/article/A7A94MCL00963VRO/full.html

    NSURL *url = [NSURL URLWithString:@"http://c.m.163.com/nc/article/A7AQOT560001124J/full.html"];

    // 2.requets

    NSURLRequest *request = [NSURLRequest requestWithURL:url];

    // 3.发送请求

    [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {

        NSDictionary *dict = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableLeaves error:nil];

        NSDictionary *news = dict[@"A7AQOT560001124J"];

        [self showNews:news];

    }];

}

- (void)showNews:(NSDictionary *)news

{

    // 1.取出网页内容

    NSString *body = news[@"body"];

    // 2.取出图片

    NSDictionary *img = [news[@"img"] lastObject];

    NSString *imgHTML = [NSString stringWithFormat:@"<img src=\"%@\" width=\"300\" height=\"171\">", img[@"src"]];

    // 2.创建一个webView，显示网页

    UIWebView *webView = [[UIWebView alloc] init];

    webView.frame = self.view.bounds;

    [self.view addSubview:webView];

    // 3.拼接网页内容

    NSString *html = [body stringByReplacingOccurrencesOfString:img[@"ref"] withString:imgHTML];

    // 4.取出新闻标题

    NSString *title = news[@"title"];

    // 5.取出新闻的时间

    NSString *time = news[@"ptime"];

    // 头部内容

    NSString *header = [NSString stringWithFormat:@"<div class=\"title\">%@</div><div class=\"time\">%@</div>", title, time];

    html = [NSString stringWithFormat:@"%@%@", header, html];

    // 链接mainBundle中的CSS文件

    NSURL *cssURL = [[NSBundle mainBundle] URLForResource:@"news" withExtension:@"css"];

    html = [NSString stringWithFormat:@"%@<link rel=\"stylesheet\" href=\"%@\">", html, cssURL];

    // 5.加载网页内容

    [webView loadHTMLString:html baseURL:nil];

}

@end

UIWebView加载POST请求

NSURL *url = [NSURL URLWithString: @"http://your_url.com"];

NSString *body = [NSString stringWithFormat: @"arg1=%@&arg2=%@", @"val1",@"val2"]; 
NSMutableURLRequest *request = [[NSMutableURLRequest alloc]initWithURL: url];

[request setHTTPMethod: @"POST"];

[request setHTTPBody: [body dataUsingEncoding: NSUTF8StringEncoding]];

[webView loadRequest: request]

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