簡單說說iOS之WKWebView的用法

JavaScript iOS開發 · 發表 2019-01-28 10:28:03

摘要： (1)標籤為UI樣式（寫了簡單的JS程式碼，目的用於講解互動） (2)onClick為JS事件，當JS想給OC傳遞引數時，採用如下程式碼：window.webkit.messageHandlers.<方法名>.postMessage(資料) <h1 style=...

(1)標籤為UI樣式（寫了簡單的JS程式碼，目的用於講解互動）

(2)onClick為JS事件，當JS想給OC傳遞引數時，採用如下程式碼：window.webkit.messageHandlers.<方法名>.postMessage(資料)

<h1 style="text-align:center;background-color: #e6b500;wdith:100px;height:40px">歡迎來到JS世界</h1>

 <p style="text-align:center"> <a href="github://callName_?https://github.com/wslcmk">Github主頁</a> ：截獲URL呼叫OC</p>

<p style="text-align:center"> <a href="http://192.168.0.116/monkey/iOS-URNetworking/commits/master">GitLab主頁</a> </p>
<p style="text-align:center"> <button id="btn1" type = "button" onclick = "jsToOcFunctionOne()" > JS呼叫OC->不帶引數</button> </p>

<p style="text-align:center"> <button id="btn2" type = "button" onclick = "jsToOcFunctionTwo()"> JS呼叫OC->帶引數</button> </p>


<p style="text-align:center"> <button id="btn3" type = "button" onclick = "showAlert()" > oc捕獲到html的彈出框</button> </p>

<!--JS語法-->
<script type = "text/javascript">

function jsToOcFunctionOne()
{
window.webkit.messageHandlers.jsToOcNoPrams.postMessage({});
}

function jsToOcFunctionTwo()
{
window.webkit.messageHandlers.jsToOcWithPrams.postMessage({"params":"我是JS引數"});
}

function showAlert()
{
alert("我來自JS世界，被你發現了");
}

//改變背景色
function changeBgColor()
{
document.body.style.backgroundColor = randomColor();
}
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2.KVO實現載入進度條以及標題

//KVO監聽：獲取進度並顯示 獲取標題並顯示
[self.webView addObserver:self forKeyPath:@"estimatedProgress" options:NSKeyValueObservingOptionNew context:nil];
[self.webView addObserver:self forKeyPath:@"title" options:NSKeyValueObservingOptionNew context:nil];

#pragma mark - KVO
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context
{
if ([keyPath isEqualToString:@"title"]&&object == _webView) {
self.title = _webView.title;
}else if ([keyPath isEqualToString:@"estimatedProgress"]
&& object == _webView)
{
self.progressView.progress = _webView.estimatedProgress;
if (_webView.estimatedProgress >= 1.0f) {
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)),
dispatch_get_main_queue(), ^{
self.progressView.progress = 0;
});
}
}
}
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3.通過攔截url方式，JS呼叫OC程式碼，決定是否跳轉（WKNavigationDelegate代理）

#pragma mark -- WKNavigationDelegateWKNavigationDelegate主要處理一些跳轉、載入處理操作
// 根據WebView對於即將跳轉的HTTP請求頭資訊和相關資訊來決定是否跳轉
- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {

NSString * urlStr = navigationAction.request.URL.absoluteString;
NSLog(@"傳送跳轉請求：%@",urlStr);
//自己定義的協議頭
NSString *htmlHeadString = @"github://";
if([urlStr hasPrefix:htmlHeadString]){
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"通過擷取URL呼叫OC" message:@"前往Github?" preferredStyle:UIAlertControllerStyleAlert];
[alertController addAction:([UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {

}])];
[alertController addAction:([UIAlertAction actionWithTitle:@"開啟" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
NSURL * url = [NSURL URLWithString:[urlStr stringByReplacingOccurrencesOfString:@"github://callName_?" withString:@""]];
[[UIApplication sharedApplication]canOpenURL:url];
}])];
[self presentViewController:alertController animated:YES completion:nil];
decisionHandler(WKNavigationActionPolicyCancel);
}else{
decisionHandler(WKNavigationActionPolicyAllow);
}
}
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4.OC獲取JS alert內容（WKUIDelegate處理警告、輸入、以及確認，這裡只列舉了alert。輸入和確認就不一一列舉了，分別是JS端confirm和prompt函式觸發）

當呼叫JS端alert函式時：通過如下代理獲取alert內容

#pragma mark -- WKUIDelegate WKUIDelegate主要處理JS指令碼，確認框，警告框等
- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler {
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"JS-alert-Action" message:message?:@"" preferredStyle:UIAlertControllerStyleAlert];
[alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
completionHandler();
}])];
[self presentViewController:alertController animated:YES completion:nil];
}
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5.OC呼叫JS程式碼，實現改變JS頁面顏色（通過evaluateJavaScript函式、jsString為JS端方法名）

#pragma mark -navigationItem Action
- (void)ocToJs
{
// changeColor()是JS方法名
NSString *jsString = [NSString stringWithFormat:@"changeBgColor()"];
[_webView evaluateJavaScript:jsString completionHandler:^(id _Nullable data, NSError * _Nullable error) {

}];
}
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6.通過接受JS方法名捕捉方法（帶引數和不帶引數，JS端向IOS傳遞引數，採用window.webkit.messageHandlers.<方法名>.postMessage(資料)）

（1）需要引入WKUserContentController、主要程式碼如下

//建立網頁配置物件
WKWebViewConfiguration *config = [[WKWebViewConfiguration alloc] init];
WKUserContentController * wkUController = [[WKUserContentController alloc] init];
//註冊一個name為jsToOcNoPrams的js方法 設定處理接收JS方法的物件
[wkUController addScriptMessageHandler:selfname:@"jsToOcNoPrams"];
[wkUController addScriptMessageHandler:selfname:@"jsToOcWithPrams"];
config.userContentController = wkUController;
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（2）核心程式碼

#pragma mark - 通過接收JS傳出訊息的name進行捕捉的回撥方法
- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message{
NSLog(@"name:%@\\\\n body:%@\\\\n frameInfo:%@\\\\n",message.name,message.body,message.frameInfo);
//用message.body獲得JS傳出的引數體
NSDictionary * parameter = message.body;
//JS呼叫OC
if([message.name isEqualToString:@"jsToOcNoPrams"]){
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"js呼叫到了oc" message:@"不帶引數" preferredStyle:UIAlertControllerStyleAlert];
[alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
}])];
[self presentViewController:alertController animated:YES completion:nil];

}else if([message.name isEqualToString:@"jsToOcWithPrams"]){
UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"js呼叫到了oc" message:parameter[@"params"] preferredStyle:UIAlertControllerStyleAlert];
[alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
}])];
[self presentViewController:alertController animated:YES completion:nil];
}

}
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