Xcode8发布以后，编译器开始不支持IOS7，所以很多应用在适配IOS10之后都不在适配IOS7了，其中包括了很多大公司，网易新闻，滴滴出行等。因此，我们公司的应用也打算淘汰IOS7。
支持到IOS8，第一个要改的自然是用WKWebView替换原来的UIWebView。WKWebView有很多明显优势:
-
更多的支持HTML5的特性
-
官方宣称的高达60fps的滚动刷新率以及内置手势
-
将UIWebViewDelegate与UIWebView拆分成了14类与3个协议,以前很多不方便实现的功能得以实现。文档
-
Safari相同的JavaScript引擎
-
占用更少的内存
UIWebView
WKWebView
因此，使用WkWebview替换UIWebView还是很有必要的。
基本使用方法
WKWebView有两个delegate,WKUIDelegate 和 WKNavigationDelegate。WKNavigationDelegate主要处理一些跳转、加载处理操作，WKUIDelegate主要处理JS脚本，确认框，警告框等。因此WKNavigationDelegate更加常用。
比较常用的方法：
#pragma mark - lifeCircle
- (void)viewDidLoad {
[super viewDidLoad];
webView = [[WKWebView alloc]init];
[self.view addSubview:webView];
[webView mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.equalTo(self.view);
make.right.equalTo(self.view);
make.top.equalTo(self.view);
make.bottom.equalTo(self.view);
}];
webView.UIDelegate = self;
webView.navigationDelegate = self;
[webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.baidu.com"]]];
}
#pragma mark - WKNavigationDelegate
// 页面开始加载时调用
- (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation{
}
// 当内容开始返回时调用
- (void)webView:(WKWebView *)webView didCommitNavigation:(WKNavigation *)navigation{
}
// 页面加载完成之后调用
- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation{
}
// 页面加载失败时调用
- (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation *)navigation{
}
// 接收到服务器跳转请求之后调用
- (void)webView:(WKWebView *)webView didReceiveServerRedirectForProvisionalNavigation:(WKNavigation *)navigation{
}
// 在收到响应后，决定是否跳转
- (void)webView:(WKWebView *)webView decidePolicyForNavigationResponse:(WKNavigationResponse *)navigationResponse decisionHandler:(void (^)(WKNavigationResponsePolicy))decisionHandler{
NSLog(@"%@",navigationResponse.response.URL.absoluteString);
//允许跳转
decisionHandler(WKNavigationResponsePolicyAllow);
//不允许跳转
//decisionHandler(WKNavigationResponsePolicyCancel);
}
// 在发送请求之前，决定是否跳转
- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler{
NSLog(@"%@",navigationAction.request.URL.absoluteString);
//允许跳转
decisionHandler(WKNavigationActionPolicyAllow);
//不允许跳转
//decisionHandler(WKNavigationActionPolicyCancel);
}
#pragma mark - WKUIDelegate
// 创建一个新的WebView
- (WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWebViewConfiguration *)configuration forNavigationAction:(WKNavigationAction *)navigationAction windowFeatures:(WKWindowFeatures *)windowFeatures{
return [[WKWebView alloc]init];
}
// 输入框
- (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(nullable NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString * __nullable result))completionHandler{
completionHandler(@"http");
}
// 确认框
- (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL result))completionHandler{
completionHandler(YES);
}
// 警告框
- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler{
NSLog(@"%@",message);
completionHandler();
}
OC与JS交互
WKWebview提供了API实现js交互 不需要借助JavaScriptCore或者webJavaScriptBridge。使用WKUserContentController实现js native交互。简单的说就是先注册约定好的方法，然后再调用。
JS调用OC方法
oc代码(有误，内存不释放):
@interface ViewController (){
WKWebView * webView;
WKUserContentController* userContentController;
}
@end
@implementation ViewController
#pragma mark - lifeCircle
- (void)viewDidLoad {
[super viewDidLoad];
//配置环境
WKWebViewConfiguration * configuration = [[WKWebViewConfiguration alloc]init];
userContentController =[[WKUserContentController alloc]init];
configuration.userContentController = userContentController;
webView = [[WKWebView alloc]initWithFrame:CGRectMake(0, 0, 100, 100) configuration:configuration];
//注册方法
[userContentController addScriptMessageHandler:self name:@"sayhello"];//注册一个name为sayhello的js方法
[self.view addSubview:webView];
[webView mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.equalTo(self.view);
make.right.equalTo(self.view);
make.top.equalTo(self.view);
make.bottom.equalTo(self.view);
}];
webView.UIDelegate = self;
webView.navigationDelegate = self;
[webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.test.com"]]];
}
- (void)dealloc{
//这里需要注意，前面增加过的方法一定要remove掉。
[userContentController removeScriptMessageHandlerForName:@"sayhello"];
}
#pragma mark - WKScriptMessageHandler
- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message{
NSLog(@"name:%@\\n body:%@\\n frameInfo:%@\\n",message.name,message.body,message.frameInfo);
}
@end
上面的OC代码如果认证测试一下就会发现dealloc并不会执行，这样肯定是不行的，会造成内存泄漏。原因是[userContentController addScriptMessageHandler:self name:@"sayhello"];这句代码造成无法释放内存。（ps:试了下用weak指针还是不能释放，不知道是什么原因。）因此还需要进一步改进，正确的写法是用一个新的controller来处理,新的controller再绕用delegate绕回来。
oc代码(正确写法):
@interface ViewController (){
WKWebView * webView;
WKUserContentController* userContentController;
}
@end
@implementation ViewController
#pragma mark - lifeCircle
- (void)viewDidLoad {
[super viewDidLoad];
//配置环境
WKWebViewConfiguration * configuration = [[WKWebViewConfiguration alloc]init];
userContentController =[[WKUserContentController alloc]init];
configuration.userContentController = userContentController;
webView = [[WKWebView alloc]initWithFrame:CGRectMake(0, 0, 100, 100) configuration:configuration];
//注册方法
WKDelegateController * delegateController = [[WKDelegateController alloc]init];
delegateController.delegate = self;
[userContentController addScriptMessageHandler:delegateController name:@"sayhello"];
[self.view addSubview:webView];
[webView mas_makeConstraints:^(MASConstraintMaker *make) {
make.left.equalTo(self.view);
make.right.equalTo(self.view);
make.top.equalTo(self.view);
make.bottom.equalTo(self.view);
}];
webView.UIDelegate = self;
webView.navigationDelegate = self;
[webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.test.com"]]];
}
- (void)dealloc{
//这里需要注意，前面增加过的方法一定要remove掉。
[userContentController removeScriptMessageHandlerForName:@"sayhello"];
}
#pragma mark - WKScriptMessageHandler
- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message{
NSLog(@"name:%@\\n body:%@\\n frameInfo:%@\\n",message.name,message.body,message.frameInfo);
}
@end
WKDelegateController代码：
#import #import @protocol WKDelegate - (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message; @end @interface WKDelegateController : UIViewController @property (weak , nonatomic) id delegate; @end
.m代码：
#import "WKDelegateController.h"
@interface WKDelegateController ()
@end
@implementation WKDelegateController
- (void)viewDidLoad {
[super viewDidLoad];
}
- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message{
if ([self.delegate respondsToSelector:@selector(userContentController:didReceiveScriptMessage:)]) {
[self.delegate userContentController:userContentController didReceiveScriptMessage:message];
}
}
@end
h5代码:
function say()
{
//前端需要用 window.webkit.messageHandlers.注册的方法名.postMessage({body:传输的数据} 来给native发送消息
window.webkit.messageHandlers.sayhello.postMessage({body: 'hello world!'});
} hello world say hello
打印出的log：
name:sayhello
body:{
body = "hello world!";
}
frameInfo:<wkframeinfo: 0x7f872060ce20; ismainframe = yes; request = { url: http: www.test.com="" }="">
注意点
-
addScriptMessageHandler要和removeScriptMessageHandlerForName配套出现，否则会造成内存泄漏。 -
h5只能传一个参数，如果需要多个参数就需要用字典或者json组装。
oc调用JS方法
代码如下：
- (void)webView:(WKWebView *)tmpWebView didFinishNavigation:(WKNavigation *)navigation{
//say()是JS方法名，completionHandler是异步回调block
[webView evaluateJavaScript:@"say()" completionHandler:^(id _Nullable result, NSError * _Nullable error) {
NSLog(@"%@",result);
}];
}
h5代码同上。
WebViewJavascriptBridge
一般来说，一个好的UI总有一个大神会开发出一个好的第三方封装框架。WebViewJavascriptBridge的作者也做了一套支持WKWebView与JS交互的第三方框架:WKWebViewJavascriptBridge。
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cocoaPods: pod 'WebViewJavascriptBridge', '~> 5.0.5'
-
github地址：https://github.com/marcuswestin/WebViewJavascriptBridge
主要方法如下：
//初始化方法 + (instancetype)bridgeForWebView:(WKWebView*)webView; + (void)enableLogging; //注册函数名 - (void)registerHandler:(NSString*)handlerName handler:(WVJBHandler)handler; //调用函数名 - (void)callHandler:(NSString*)handlerName; - (void)callHandler:(NSString*)handlerName data:(id)data; - (void)callHandler:(NSString*)handlerName data:(id)data responseCallback:(WVJBResponseCallback)responseCallback; //重置 - (void)reset; //设置WKNavigationDelegate - (void)setWebViewDelegate:(id)webViewDelegate;
基本的实现方法和上面写的差不多，就是封装了一下，有兴趣的童鞋可以自己pod下来使用。
前不久把项目中的UIWebView更新到WkWebView，解决了一大堆问题，但是也遗留了一大堆问题，比方说cookie。
以前UIWebView会自动去NSHTTPCookieStorage中读取cookie，但是WKWebView并不会去读取,因此导致cookie丢失以及一系列问题，解决方式就是在request中手动帮其添加上。
mainWebView.UIDelegate = self;
mainWebView.navigationDelegate = self;
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://www.test.com"]];
[request addValue:[self readCurrentCookieWithDomain:@"http://www.test.com/"] forHTTPHeaderField:@"Cookie"];
[mainWebView loadRequest:request];
- (NSString *)readCurrentCookieWithDomain:(NSString *)domainStr{
NSHTTPCookieStorage*cookieJar = [NSHTTPCookieStorage sharedHTTPCookieStorage];
NSMutableString * cookieString = [[NSMutableString alloc]init];
for (NSHTTPCookie*cookie in [cookieJar cookies]) {
[cookieString appendFormat:@"%@=%@;",cookie.name,cookie.value];
}
//删除最后一个“；”
[cookieString deleteCharactersInRange:NSMakeRange(cookieString.length - 1, 1)];
return cookieString;
}
但是这只能解决第一次进入的cookie问题，如果页面内跳转（a标签等）还是取不到cookie，因此还要再加代码。
- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation {
//取出cookie
NSHTTPCookieStorage *cookieStorage = [NSHTTPCookieStorage sharedHTTPCookieStorage];
//js函数
NSString *JSFuncString =
@"function setCookie(name,value,expires)
{
var oDate=new Date();
oDate.setDate(oDate.getDate()+expires);
document.cookie=name+'='+value+';expires='+oDate+';path=/'
}
function getCookie(name)
{
var arr = document.cookie.match(new RegExp('(^| )'+name+'=({FNXX==XXFN}*)(;|$)'));
if(arr != null) return unescape(arr[2]); return null;
}
function delCookie(name)
{
var exp = new Date();
exp.setTime(exp.getTime() - 1);
var cval=getCookie(name);
if(cval!=null) document.cookie= name + '='+cval+';expires='+exp.toGMTString();
}";
//拼凑js字符串
NSMutableString *JSCookieString = JSFuncString.mutableCopy;
for (NSHTTPCookie *cookie in cookieStorage.cookies) {
NSString *excuteJSString = [NSString stringWithFormat:@"setCookie('%@', '%@', 1);", cookie.name, cookie.value];
[JSCookieString appendString:excuteJSString];
}
//执行js
[webView evaluateJavaScript:JSCookieString completionHandler:nil];
}