記錄一次H5生成blob文件url，iOS app內(nèi)部WKWebView不能正常下載問(wèn)題。
因?yàn)槲野l(fā)現(xiàn)在系統(tǒng)瀏覽器Safari里能下載，按理說(shuō)在WKWebView里也能，后來(lái)查了下資料解決了這個(gè)問(wèn)題。
1.首先要攔截跳轉(zhuǎn)把以blob開(kāi)頭的跳轉(zhuǎn)鏈接轉(zhuǎn)成WKNavigationActionPolicyDownload 代碼如下，注意這個(gè)只能在iOS14.5以后才能使用

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler{
  if([navigationAction.request.URL.absoluteString hasPrefix:@"blob"]){
        if (@available(iOS 14.5, *)) {
            decisionHandler(WKNavigationActionPolicyDownload);
        } else {
            // Fallback on earlier versions
            decisionHandler(WKNavigationActionPolicyCancel);
        }
    }
    else{
        decisionHandler(WKNavigationActionPolicyAllow);
    }
}

2.然后實(shí)現(xiàn)代理方法

- (void)webView:(WKWebView *)webView navigationAction:(WKNavigationAction *)navigationAction didBecomeDownload:(WKDownload *)download API_AVAILABLE(ios(14.5)){
    download.delegate = self;// 遵守WKDownloadDelegate
}

3.最后實(shí)現(xiàn)WKDownloadDelegate代理

- (void)download:(WKDownload *)download decideDestinationUsingResponse:(NSURLResponse *)response suggestedFilename:(NSString *)suggestedFilename completionHandler:(void (^)(NSURL * _Nullable))completionHandler API_AVAILABLE(ios(14.5)){
    NSURL *temporaryDirectory = [NSFileManager.defaultManager temporaryDirectory];
    NSURL *url = [temporaryDirectory URLByAppendingPathComponent:suggestedFilename];
    completionHandler(url);
    //這里是提示框
    [ShowAlertTool showSheetwithTitles:@[@"分享文件"] confirmBlock:^(NSInteger number) {
        SHOW_HUD;
        XMainAfter(1, ^{
            DISMISS_HUD;
        });
      //這里是分享文件 封的一個(gè)方法，內(nèi)部用的UIActivityViewController ，下面順便會(huì)把分享代碼也貼出來(lái)
        [SFShare showSystemShare:@[url] completion:nil];
    }];
}

4.分享方法的代碼

+(void)showSystemShare:(NSArray *)items completion:(ShareCallBackBlock)shareBlock{
    UIActivityViewController *activityView = [[UIActivityViewController alloc] initWithActivityItems:items applicationActivities:nil];
    activityView.excludedActivityTypes = @[UIActivityTypePostToFacebook,
                                           UIActivityTypeMessage,
                                           UIActivityTypePostToTwitter,
                                           UIActivityTypePostToWeibo,
                                           UIActivityTypeMail,
                                           UIActivityTypePrint,
                                           UIActivityTypeCopyToPasteboard,
                                           UIActivityTypeAssignToContact,
//                                           UIActivityTypeSaveToCameraRoll,
                                           UIActivityTypeAddToReadingList,
                                           UIActivityTypePostToFlickr,
                                           UIActivityTypePostToVimeo,
                                           UIActivityTypePostToTencentWeibo,
                                           UIActivityTypeAirDrop,
                                           UIActivityTypeOpenInIBooks,
                                           UIActivityTypeMarkupAsPDF,
                                        ];
    activityView.completionWithItemsHandler = ^(UIActivityType __nullable activityType, BOOL completed, NSArray * __nullable returnedItems, NSError * __nullable activityError){
        if (activityType == UIActivityTypeSaveToCameraRoll) {//保存到相冊(cè)
            NSString *msg = nil ;
             if(!completed){
                 msg = @"保存圖片失敗" ;
             }else{
                 msg = @"保存圖片成功" ;
             }
             [[UIApplication sharedApplication].keyWindow makeToast:(msg) duration:1.5 position:CSToastPositionCenter];
        }
        if(shareBlock){
            shareBlock(completed);
        }
    };
    
    [[UIApplication sharedApplication].keyWindow.rootViewController presentViewController:activityView animated:YES completion:nil];
}

總結(jié)：這個(gè)功能只能在iOS14.5以上才能使用，因?yàn)榫W(wǎng)上關(guān)于iOS處理的資料有點(diǎn)少，就特地分享出來(lái)。希望能幫到iOS開(kāi)發(fā)小伙伴們。