WKWebView使用

WKWebView比之之前使用的UIWebView更加具有优势，UIWebView更加的笨重，UIWebView占用更多的内存，且内存的峰值更加的夸张，WKWebView加载的速度也更快，而且其更多的支持HTML5的特性，官方宣称的高达60fps的公洞刷新率以及内置的手势。

以下是一些WKWebView的一些使用方法及代理方法

加载链接和UIWebView类似

懒加载方法：

- (WKWebView *)webView {
    if (_webView == nil) {
        // js配置
        WKUserContentController *userContentController = [[WKUserContentController alloc] init];
        [userContentController addScriptMessageHandler:self name:@"webViewLoadStart"];
        [userContentController addScriptMessageHandler:self name:@"webViewLoadFinish"];
        [userContentController addScriptMessageHandler:self name:@"webViewLogout"];
        [userContentController addScriptMessageHandler:self name:@"webViewSuccess"];

        // WKWebView的配置
        WKWebViewConfiguration *configuration = [[WKWebViewConfiguration alloc] init];
        configuration.userContentController = userContentController;
        
        // 显示WKWebView
        _webView = [[WKWebView alloc] initWithFrame:self.view.frame configuration:configuration];
        _webView.UIDelegate = self; // 设置WKUIDelegate代理
        _webView.navigationDelegate = self; // 设置WKNavigationDelegate代理
        [self.view addSubview:_webView];
    }
    return _webView;
}

在其中的

- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message方法中主要是收到JS的回执脚本就会运行一次

可以在这个方法里面进行app和js的交互

下面是WKUIDelegate一些代理的方法，可以用于输入框，弹出窗的使用

和UIWebView类似的加载，成功，失败的代理方法类似

/// 1 页面开始加载
- (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation;
/// 2 开始获取到网页内容时返回
- (void)webView:(WKWebView *)webView didCommitNavigation:(WKNavigation *)navigation;
/// 3 页面加载完成之后调用
- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation;
/// 4 页面加载失败时调用
- (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation *)navigation;

#pragma mark - WKUIDelegate
#pragma mark alert弹出框
- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler {
    NSLog(@"%s", __FUNCTION__);
    // 确定按钮
    UIAlertAction *alertAction = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
        completionHandler();
    }];
    // alert弹出框
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:message message:nil preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:alertAction];
    [self presentViewController:alertController animated:YES completion:nil];
}

#pragma mark Confirm选择框
- (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(nonnull NSString *)message initiatedByFrame:(nonnull WKFrameInfo *)frame completionHandler:(nonnull void (^)(BOOL))completionHandler {
    NSLog(@"%s", __FUNCTION__);
    // 按钮
    UIAlertAction *alertActionCancel = [UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
        // 返回用户选择的信息
        completionHandler(NO);
    }];
    UIAlertAction *alertActionOK = [UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        completionHandler(YES);
    }];
    // alert弹出框
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:message message:nil preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:alertActionCancel];
    [alertController addAction:alertActionOK];
    [self presentViewController:alertController animated:YES completion:nil];
}

#pragma mark TextInput输入框
- (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(nonnull NSString *)prompt defaultText:(nullable NSString *)defaultText initiatedByFrame:(nonnull WKFrameInfo *)frame completionHandler:(nonnull void (^)(NSString * _Nullable))completionHandler {
    NSLog(@"%s",__FUNCTION__);
    // alert弹出框
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:prompt message:nil preferredStyle:UIAlertControllerStyleAlert];
    // 输入框
    [alertController addTextFieldWithConfigurationHandler:^(UITextField * _Nonnull textField) {
        textField.placeholder = defaultText;
    }];
    // 确定按钮
    [alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        // 返回用户输入的信息
        UITextField *textField = alertController.textFields.firstObject;
        completionHandler(textField.text);
    }]];
    // 显示
    [self presentViewController:alertController animated:YES completion:nil];
}