WKWebView 獲取標題+進度條+常用代理方法以及native相容處理

NB_Token發表於2017-10-27
WebView

1.屬性宣告

@property (copy,nonatomic)   NSString   *url;
@property (copy,nonatomic)   NSString   *pageTitle;



@property (nonatomic, strong) WKWebView *webView;
@property (nonatomic , strong) UIProgressView *processView;

@property (strong,nonatomic) UIBarButtonItem    *backItem;//goBack
@property (strong,nonatomic) UIBarButtonItem    *closeItem;//pop

@property (strong,nonatomic) UILabel    *errorLabel;

@property (copy,nonatomic)   NSString   *currentUrl;//當前載入頁面的url


2.遵守協議  

<WKNavigationDelegate,WKUIDelegate>

3. viewDidLoad 建立UI 

- (void)viewDidLoad {
    [super viewDidLoad];

    self.title = self.pageTitle;
    [self loadWebView];
}



-(void)loadWebView {
    
    _webView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 0, kScreenWidth, kScreenHeight-64)];
    [self.view addSubview: self.webView];
    _webView.allowsBackForwardNavigationGestures = YES;
    _webView.navigationDelegate = self;
    _webView.UIDelegate = self;
    _webView.contentMode = UIViewContentModeScaleAspectFit;
    _webView.scrollView.showsVerticalScrollIndicator = NO;
    _webView.scrollView.showsHorizontalScrollIndicator = NO;
    
    [_webView addObserver:self
             forKeyPath:@"estimatedProgress"
                options:NSKeyValueObservingOptionNew
                context:nil];
    
    [_webView addObserver:self
               forKeyPath:@"title"
                  options:NSKeyValueObservingOptionNew
                  context:NULL];

    
    // process
    _processView = [[UIProgressView alloc] initWithFrame:CGRectMake(0, 1, kScreenWidth, 1)];
    _processView.progressTintColor = MAINCOLOR;
    _processView.trackTintColor = [UIColor whiteColor];
    [self.view addSubview:self.processView];
    
    
    NSURL *url = [NSURL URLWithString:self.url];
    NSURLRequest *request = [[NSURLRequest alloc]initWithURL:url];
    [self.webView loadRequest:request];
}

4. viewWillAppear 建立導航按鈕 

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    [self setNav];
}

//建立導航條右側 返回 和 關閉 的按鈕
- (void)setNav {
    if (self.navigationController.viewControllers.count > 1) {
        UIButton *backBtn = [UIButton buttonWithType:(UIButtonTypeCustom)];
        backBtn.frame = CGRectMake(0, 0, 50, 40);
        [backBtn setTitle:@" 返回" forState:UIControlStateNormal];
        [backBtn.titleLabel setFont:[UIFont systemFontOfSize:16]];
        [backBtn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
        [backBtn setImage:[UIImage imageNamed:@"return"] forState:UIControlStateNormal];
        [backBtn setImage:[UIImage imageNamed:@"return"] forState:UIControlStateHighlighted];
        [backBtn setContentHorizontalAlignment:(UIControlContentHorizontalAlignmentLeft)];
        [backBtn addTarget:self action:@selector(backClick) forControlEvents:UIControlEventTouchUpInside];
        [backBtn.imageView mas_makeConstraints:^(MASConstraintMaker *make) {
            make.left.mas_equalTo(backBtn);
            make.height.mas_equalTo(@18);
            make.centerY.mas_equalTo(backBtn);
        }];
        self.backItem = [[UIBarButtonItem alloc] initWithCustomView:backBtn];
        
        
        UIButton *closeBtn = [UIButton buttonWithType:(UIButtonTypeCustom)];
        [closeBtn setContentHorizontalAlignment:(UIControlContentHorizontalAlignmentLeft)];
        closeBtn.frame = CGRectMake(0, 0, 40, 40);
        [closeBtn setTitle:@"關閉" forState:UIControlStateNormal];
        [closeBtn.titleLabel setFont:backBtn.titleLabel.font];
        [closeBtn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
        [closeBtn addTarget:self action:@selector(closeClick) forControlEvents:UIControlEventTouchUpInside];
        self.closeItem = [[UIBarButtonItem alloc] initWithCustomView:closeBtn];
        
        self.navigationItem.leftBarButtonItem = self.backItem;
    }
}


5. viewDidDisappear  清理快取，移除觀察者 

-(void)viewDidDisappear:(BOOL)animated{
    
    [self.webView stopLoading];
    [self.webView removeObserver:self forKeyPath:@"estimatedProgress"];
    [self.webView removeObserver:self forKeyPath:@"title"];
    self.webView = nil;
    NSURLCache * cache = [NSURLCache sharedURLCache];
    [cache removeAllCachedResponses];
    [cache setDiskCapacity:0];
    [cache setMemoryCapacity:0];
    [super viewDidDisappear:animated];
}

6. KVO 監聽進度變化和標題變化 

#pragma mark ----- KVO ----------
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
    
    if ([keyPath isEqualToString:@"estimatedProgress"]) {
        
        if (object == self.webView) {
            [self.processView setAlpha:1.0f];
            [self.processView setProgress:self.webView.estimatedProgress animated:YES];
            
            if(self.webView.estimatedProgress >= 1.0f) {
                
                [UIView animateWithDuration:0.3 delay:0.5 options:UIViewAnimationOptionCurveEaseOut animations:^{
                    [self.processView setAlpha:0.0f];
                } completion:^(BOOL finished) {
                    [self.processView setProgress:0.0f animated:NO];
                }];
            }
        }
        else
        {
            [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
        }
        
    }
    else if ([keyPath isEqualToString:@"title"])
    {
        if (object == self.webView) {
            if (self.webView.title.length != 0) {
                self.title = self.webView.title;
            }
            
        }
        else
        {
            [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
            
        }
    }
    else {
        
        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
    }
}


7. 常用代理方法

#pragma mark ------- WKNavigationDelegate -----
//網頁開始載入
- (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation {
    self.currentUrl = webView.URL.absoluteString;
    NSLog(@"currentUrl====%@",self.currentUrl);
}


//網頁載入完成
- (void)webView:(WKWebView *)webView didFinishNavigation:(null_unspecified WKNavigation *)navigation {
    if (webView.backForwardList.backList.count > 0) {
        self.navigationItem.leftBarButtonItems = @[self.backItem,self.closeItem];
    }
}

//網頁載入失敗
- (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(null_unspecified WKNavigation *)navigation withError:(NSError *)error {
    [self.view addSubview:self.errorLabel];
}

8. 回退和關閉按鈕點選方法 

#pragma mark -------- action ----------
//回退goback
- (void)backClick {
 
    HtmlModel *model = [LocalStoreTools getHtmlModel];
    if ([self.url rangeOfString:model.alarm4Dosing].location != NSNotFound &&
        [self.currentUrl rangeOfString:@"index.html"].location != NSNotFound) {//用藥提醒
        [self closeClick];
    } else {
        if ([self.webView canGoBack]) {
            [self.webView goBack];
        } else {
            [self closeClick];
        }
    }
}
//關閉pop
- (void)closeClick {
    if (self.presentingViewController != nil) {
        [self dismissViewControllerAnimated:NO completion:nil];
    } else {
        [self.navigationController popViewControllerAnimated:YES];
    }
}


9. native相容處理 

//提示框
- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler{
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"提示" message:message?:@"" preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:([UIAlertAction actionWithTitle:@"確認" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        completionHandler();
    }])];
    [self presentViewController:alertController animated:YES completion:nil];
    
}
//彈出框
- (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL))completionHandler{
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"提示" message:message?:@"" preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:([UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
        completionHandler(NO);
    }])];
    [alertController addAction:([UIAlertAction actionWithTitle:@"確認" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        completionHandler(YES);
    }])];
    [self presentViewController:alertController animated:YES completion:nil];
}
//輸入框
- (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString * _Nullable))completionHandler{
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:prompt message:@"" preferredStyle:UIAlertControllerStyleAlert];
    [alertController addTextFieldWithConfigurationHandler:^(UITextField * _Nonnull textField) {
        textField.text = defaultText;
    }];
    [alertController addAction:([UIAlertAction actionWithTitle:@"完成" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        completionHandler(alertController.textFields[0].text?:@"");
    }])];
    
    [self presentViewController:alertController animated:YES completion:nil];
}

//處理 target = "__blank"
- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler
{
    if (!navigationAction.targetFrame.isMainFrame) {
        [webView evaluateJavaScript:@"var a = document.getElementsByTagName('a');for(var i=0;i<a.length;i++){a[i].setAttribute('target','');}" completionHandler:nil];
    }
    decisionHandler(WKNavigationActionPolicyAllow);
}



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