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How to use EvaluateFunctionAsync method of PuppeteerSharp.Page class
Best Puppeteer-sharp code snippet using PuppeteerSharp.Page.EvaluateFunctionAsync
BaseScraper.cs
Source:BaseScraper.cs 
...92 }93 public virtual async Task<double> GetCurrentScrollHeight(string selector)94 {95 var chSelectorFunc = ScraperConstants.FUNC_SELECT_SIMPLE.Replace("{{SPECIAL}}", ".scrollHeight");96 return await CurrentPage.EvaluateFunctionAsync<double>(chSelectorFunc, selector);97 }98 public virtual async Task<double> GetCurrentScroll(string selector, bool addClientHeight = true)99 {100 var chSelectorFunc = ScraperConstants.FUNC_SELECT_SIMPLE.Replace("{{SPECIAL}}", ".scrollTop");101 var scrollTop = await CurrentPage.EvaluateFunctionAsync<double>(chSelectorFunc, selector);102 if (addClientHeight)103 {104 var clHeightFunc = ScraperConstants.FUNC_SELECT_SIMPLE.Replace("{{SPECIAL}}", ".clientHeight");105 var clientHeight = await CurrentPage.EvaluateFunctionAsync<double>(clHeightFunc, selector);106 scrollTop += clientHeight;107 }108 return scrollTop;109 }110 public virtual async Task ScrollTo(string selector, int toHeight, bool aproximate = true, bool useWindow = false)111 {112 var newHeight = toHeight;113 if (aproximate)114 newHeight -= 100;115 var scrollFuncCall = ".scrollTo(0, " + newHeight + ")";116 var scrollBottom = (useWindow ? ScraperConstants.WINDOW_FUNCTION : ScraperConstants.FUNC_SELECT_SIMPLE).Replace("{{SPECIAL}}", scrollFuncCall);117 await CurrentPage.EvaluateFunctionAsync(scrollBottom, selector);118 }119 public virtual async Task CloseAnnoyingElements()120 {121 var appSettings = SettingsManager.Settings;122 if (appSettings.ANNOYING_ELEMENTS == null || appSettings.ANNOYING_ELEMENTS.Length == 0)123 return;124 await this.CloseAnnoyingElements(appSettings.ANNOYING_ELEMENTS);125 }126 public virtual async Task CloseAnnoyingElements(string[] selectors)127 {128 var stillSearching = true;129 while (stillSearching)130 {131 stillSearching = false;...
Program.cs
Source:Program.cs
...62 var jscode = @"() => {63 const selectors = Array.from(document.querySelectorAll(`div.du4w35lb.k4urcfbm.l9j0dhe7.sjgh65i0`)); 64 return selectors.map( t=> {return {content: t.innerHTML}});65 }";66 var results = await page.EvaluateFunctionAsync<Content[]>(jscode);67 List<Data> authorNamesAndText = new List<Data>();68 foreach (var result in results)69 {70 Data data = new Data();71 await page.SetContentAsync(result.content);72 Thread.Sleep(500);73 string content = "", content2 = "";74 var elementHandle = await page.QuerySelectorAsync("span.d2edcug0.hpfvmrgz.qv66sw1b.c1et5uql.lr9zc1uh.a8c37x1j.keod5gw0.nxhoafnm.aigsh9s9.d3f4x2em.fe6kdd0r.mau55g9w.c8b282yb.iv3no6db.jq4qci2q.a3bd9o3v.knj5qynh.m9osqain.hzawbc8m");75 if (elementHandle != null)76 {77 try78 {79 content = await elementHandle.QuerySelectorAsync("span").EvaluateFunctionAsync<string>("node => node.innerText");80 }81 catch (Exception e1)82 {83 Console.WriteLine("error in getting content: " + e1.Message);84 }85 }86 if (content != "")87 {88 Thread.Sleep(500);89 try90 {91 content2 = await page.QuerySelectorAsync("div.kvgmc6g5.cxmmr5t8.oygrvhab.hcukyx3x.c1et5uql.ii04i59q").EvaluateFunctionAsync<string>("node => node.innerText");92 }93 catch (Exception e2)94 {95 Console.WriteLine("error in getting content: " + e2.Message);96 }97 data.author = content;98 data.posttext = content2;99 authorNamesAndText.Add(data);100 }101 }102 //print author and post list103 foreach (Data ap in authorNamesAndText)104 {105 Console.WriteLine("Author: " + ap.author);...
SaveWebPage.xaml.cs
Source:SaveWebPage.xaml.cs
...101 PuppeteerSharp.PdfOptions pdfOptions = new PuppeteerSharp.PdfOptions();102 pdfOptions.DisplayHeaderFooter = false; //æ¯å¦æ¾ç¤ºé¡µç页è103 pdfOptions.FooterTemplate = ""; //页èææ¬104105 var width = await page.EvaluateFunctionAsync<int>("function getWidth(){return document.body.scrollWidth}");106 var height = await page.EvaluateFunctionAsync<int>("function getHeight(){return document.body.scrollHeight}");107108 pdfOptions.Width = $"{width}px";109 pdfOptions.Height = $"{height}px";110111 pdfOptions.HeaderTemplate = ""; //页çææ¬112 pdfOptions.Landscape = false; //çº¸å¼ æ¹å false-åç´ true-æ°´å¹³113 pdfOptions.MarginOptions = new PuppeteerSharp.Media.MarginOptions() { Bottom = "0px", Left = "0px", Right = "0px", Top = "0px" }; //çº¸å¼ è¾¹è·ï¼éè¦è®¾ç½®å¸¦åä½çå¼ï¼é»è®¤å¼æ¯None114 pdfOptions.Scale = 1m; //PDF缩æ¾ï¼ä»0-1115 pdfOptions.PrintBackground = true;116117 var fileName = Environment.CurrentDirectory + $"\\download\\{await page.GetTitleAsync()}.pdf";118119 if (System.IO.File.Exists(fileName))120 {
...
Get-ScraperMobileVikings.cs
Source:Get-ScraperMobileVikings.cs
...65 decimal credits;66 try {67 var creditField = await page.WaitForSelectorAsync(68 "body > div:nth-child(1) > div:nth-child(3) > div > div > main > div > section > div > section > section.MvSection.balanceItemSection > div > div > div:nth-child(2) > strong");69 var creditText = await creditField.EvaluateFunctionAsync<string>("e => e.innerText");70 var creditMatch = Regex.Match(creditText, @"^[^\d]*(\d+)[,\.](\d+)$");71 if (creditMatch.Success) {72 creditText = creditMatch.Groups[1].Value + CultureInfo.InvariantCulture.NumberFormat.NumberDecimalSeparator + (creditMatch.Groups[2].Value ?? "0");73 credits = decimal.Parse(creditText, CultureInfo.InvariantCulture.NumberFormat);74 } else {75 throw new Exception($"Credits not found ({creditText})");76 }77 } catch (PuppeteerSharp.WaitTaskTimeoutException) {78 var creditField = await page.WaitForSelectorAsync(79 "body > div:nth-child(1) > div:nth-child(3) > div > div > main > div > section > div > section > section");80 var creditText = await creditField.EvaluateFunctionAsync<string>("e => e.innerText");81 if (creditText.Contains("Geen\nbelwaarde"))82 credits = 0m;83 else84 throw new Exception($"Credits not found (No credits left?)");85 }8687 // Get points88 System.Threading.Thread.Sleep(3000);89 decimal? points = null;90 if (!DontIncludePoints)91 {92 await page.GoToAsync("https://mobilevikings.be/en/my-viking/viking-points");93 Match pointMatch = null;94 string pointText = "";95 for (int i = 0; i < 10 && (pointMatch == null || !pointMatch.Success); i++)96 {97 System.Threading.Thread.Sleep(1000);98 var pointField = await page.WaitForSelectorAsync(99 "body > div:nth-child(1) > div:nth-child(3) > div > div > main > div > section.vikingPointsView__header.vikingPointsViewHeader > div.vikingPointsViewHeader__details.vikingPointsViewHeaderItem.available > div");100 pointText = await pointField.EvaluateFunctionAsync<string>("e => e.innerText");101 pointMatch = Regex.Match(pointText, @"^[^\d]*(\d+)[,\.](\d+)$");102 }103 if (pointMatch.Success) {104 pointText = pointMatch.Groups[1].Value + CultureInfo.InvariantCulture.NumberFormat.NumberDecimalSeparator + (pointMatch.Groups[2].Value ?? "0");105 points = decimal.Parse(pointText, CultureInfo.InvariantCulture.NumberFormat);106 } else {107 throw new Exception($"Points not found ({pointText})");108 }109 }110111 // Bundle112 return new MobileVikings { 113 Credits = credits,114 Points = points
...
AvitoPostParser.cs
Source:AvitoPostParser.cs
...43 };44 }45 private async Task<string> GetAuthorName(PuppeteerSharp.Page page)46 {47 var sellerInfoName = await page.WaitForSelectorAsync(".seller-info-name.js-seller-info-name a").EvaluateFunctionAsync<string>("element => element.innerHTML");48 sellerInfoName = sellerInfoName.Trim();49 var sellerInfoValueElement = await page.QuerySelectorAsync("div.seller-info-label + div.seller-info-value");50 if (sellerInfoValueElement != null)51 {52 var sellerInfoValue = (await sellerInfoValueElement.EvaluateFunctionAsync<string>("element => element.innerHTML")).Trim();53 sellerInfoName += ": " + sellerInfoValue;54 }55 return sellerInfoName;56 }57 private async Task<string> GetPhoneNumber(PuppeteerSharp.Page page)58 {59 string phoneImage = await page.WaitForSelectorAsync("div[data-marker='phone-popup/content'] img[data-marker='phone-popup/phone-image']").EvaluateFunctionAsync<string>("element => element.src");60 string imageStr = phoneImage.Substring(phoneImage.IndexOf(",") + 1).Trim();61 byte[] imageByte = System.Convert.FromBase64String(imageStr);62 using (var engine = new TesseractEngine("./tessdata", "eng", EngineMode.Default))63 {64 using (var memoryStream = new MemoryStream(imageByte))65 {66 var file = Pix.LoadFromMemory(memoryStream.ToArray());67 var page1 = engine.Process(file);68 return page1.GetText().Trim();69 }70 }71 }72 }73}...
test vueJS.csx
Source:test vueJS.csx
...50async Task waitForProgramEnd(){51 /*52 This stuff keeps the browser open until our program is done.53 */54 await page.EvaluateFunctionAsync(@"55 ()=> {56 window.programDone = false;57 }58 ");59 await page.WaitForExpressionAsync("window.programDone === true", new WaitForFunctionOptions{60 Timeout = 0 // disable timeout61 });62 Console.WriteLine("Program finished triggered");63 // program is done so close everything out64 await page.CloseAsync();65 await browser.CloseAsync();66}67await waitForProgramEnd();...
PuppeteerHelper.cs
Source:PuppeteerHelper.cs
...8 public static class PuppeteerHelper9 {10 public static async Task<string> GetTextboxValue(Page page, string selector)11 {12 JToken value = await page.EvaluateFunctionAsync(@"(selector) => {13 return document.querySelector(selector).value;14 }", selector);15 return value.Value<string>();16 }17 public static async Task<JToken> GetTableData(Page page, string dataSelector, List<ScrapeItemSetting> mappings)18 {19 var tData = await page.EvaluateFunctionAsync(@"(dataSelector, tableMapping) => {20 const data = Array.from(document.querySelectorAll(dataSelector));21 var items = [];22 data.forEach((item, index) => {23 var obj = {};24 tableMapping.forEach((i, idx) => {25 setObject(obj, i, item);26 });27 items.push(obj);28 });29 return items;30 }", dataSelector, mappings);31 return tData;32 }33 public static async Task<JToken> GetElements(Page page, List<ScrapeItemSetting> mappings)34 {35 var tData = await page.EvaluateFunctionAsync(@"(mappings) => {36 var items = [];37 mappings.forEach((i, idx) => {38 var obj = {};39 var element = $(document);40 setObject(obj, i, element);41 items.push(obj);42 });43 return items;44 }", mappings);45 return tData;46 }47 }48}...
CapturingService.cs
Source:CapturingService.cs
1using PuppeteerSharp;2namespace HeadfulBrowserAudioVideoCapturingService;3public class CapturingService4{5 public async Task StartCapturing(Page extensionPage) => await extensionPage.EvaluateFunctionAsync("START_RECORDING", new StartRecordingSettings());6 public async Task StopCapturing(Page extensionPage) => await extensionPage.EvaluateFunctionAsync("STOP_RECORDING");7}...
EvaluateFunctionAsync
Using AI Code Generation
1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5 {6 static async Task Main(string[] args)7 {8 await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);9 var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = true });10 var page = await browser.NewPageAsync();11 var title = await page.EvaluateFunctionAsync<string>("() => document.title");12 Console.WriteLine(title);13 await browser.CloseAsync();14 }15 }16}17using System;18using System.Threading.Tasks;19using PuppeteerSharp;20{21 {22 static async Task Main(string[] args)23 {24 await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);25 var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = true });26 var page = await browser.NewPageAsync();27 var title = await page.MainFrame.EvaluateFunctionAsync<string>("() => document.title");28 Console.WriteLine(title);29 await browser.CloseAsync();30 }31 }32}33using System;34using System.Threading.Tasks;35using PuppeteerSharp;36{37 {38 static async Task Main(string[] args)39 {40 await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);41 var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = true });42 var page = await browser.NewPageAsync();43 var title = await page.EvaluateFunctionAsync<string>("() => document.title");44 Console.WriteLine(title);45 await browser.CloseAsync();46 }47 }48}49using System;50using System.Threading.Tasks;51using PuppeteerSharp;52{53 {54 static async Task Main(string[] args)55 {56 await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);
EvaluateFunctionAsync
Using AI Code Generation
1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5 {6 static async Task Main(string[] args)7 {8 var browser = await Puppeteer.LaunchAsync(new LaunchOptions9 {10 });11 var page = await browser.NewPageAsync();12 var result = await page.EvaluateFunctionAsync("() => 1 + 2");13 Console.WriteLine(result);14 await browser.CloseAsync();15 }16 }17}18public Task<JsonElement> EvaluateExpressionAsync(string expression, object[] args = null)19using System;20using System.Threading.Tasks;21using PuppeteerSharp;22{23 {24 static async Task Main(string[] args)25 {26 var browser = await Puppeteer.LaunchAsync(new LaunchOptions27 {28 });29 var page = await browser.NewPageAsync();30 var result = await page.EvaluateExpressionAsync("1 + 2");31 Console.WriteLine(result);32 await browser.CloseAsync();33 }34 }35}36public Task<JSHandle> EvaluateFunctionHandleAsync(string function, object[] args = null)
EvaluateFunctionAsync
Using AI Code Generation
1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5 {6 static async Task Main(string[] args)7 {8 {9 ExecutablePath = @"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe"10 };11 using (var browser = await Puppeteer.LaunchAsync(options))12 using (var page = await browser.NewPageAsync())13 {14 var result = await page.EvaluateFunctionAsync<string>("() => { return 'hello world'; }");15 Console.WriteLine(result);16 }17 }18 }19}
EvaluateFunctionAsync
Using AI Code Generation
1{2 {3 static void Main(string[] args)4 {5 var task = MainAsync(args);6 task.Wait();7 }8 static async Task MainAsync(string[] args)9 {10 var browser = await Puppeteer.LaunchAsync(new LaunchOptions11 {12 ExecutablePath = @"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe",13 Args = new string[] { "--no-sandbox" }14 });15 var page = await browser.NewPageAsync();16 var result = await page.EvaluateFunctionAsync("() => { return 1 + 2; }");17 Console.WriteLine(result);18 Console.ReadKey();19 }20 }21}
EvaluateFunctionAsync
Using AI Code Generation
1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5 {6 static async Task Main(string[] args)7 {8 var browser = await Puppeteer.LaunchAsync(new LaunchOptions9 {10 });11 var page = await browser.NewPageAsync();12 var h1Value = await page.EvaluateFunctionAsync<string>("() => document.querySelector('h1').innerText");13 Console.WriteLine("h1 value is: " + h1Value);14 Console.ReadLine();15 await browser.CloseAsync();16 }17 }18}
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Most used method in Page
- FrameManagerGetFrames
- workersValuesToArray
- PopupGetInvocationList
- clientDisconnected
- SetGeolocationAsync
- SetDragInterceptionAsync
- MetricsAsync
- TapAsync
- QuerySelectorAsync
- QuerySelectorAllAsync
- QuerySelectorAllHandleAsync
- XPathAsync
- EvaluateExpressionHandleAsync
- EvaluateFunctionHandleAsync
- EvaluateOnNewDocumentAsync
- EvaluateFunctionOnNewDocumentAsync
- EvaluateExpressionOnNewDocumentAsync
- QueryObjectsAsync
- SetRequestInterceptionAsync
- SetOfflineModeAsync
- EmulateNetworkConditionsAsync
- GetCookiesAsync
- SetCookieAsync
- DeleteCookieAsync
- AddScriptTagAsync
- AddStyleTagAsync
- ExposeFunctionAsync
- TResult
- GetContentAsync
- SetContentAsync
- GoToAsync
- PdfAsync
- PdfStreamAsync
- PdfDataAsync
- SetJavaScriptEnabledAsync
- SetBypassCSPAsync
- EmulateMediaAsync
- EmulateMediaTypeAsync
- EmulateMediaFeaturesAsync
- SetViewportAsync
- EmulateAsync
- ScreenshotAsync
- ScreenshotStreamAsync
- ScreenshotBase64Async
- ScreenshotDataAsync
- GetTitleAsync
- CloseAsync
- SetCacheEnabledAsync
- ClickAsync
- HoverAsync
- FocusAsync
- TypeAsync
- EvaluateExpressionAsync
- EvaluateFunctionAsync
- SetUserAgentAsync
- SetExtraHttpHeadersAsync
- AuthenticateAsync
- ReloadAsync
- SelectAsync
- WaitForTimeoutAsync
- WaitForFunctionAsync
- WaitForExpressionAsync
- WaitForSelectorAsync
- WaitForXPathAsync
- WaitForNavigationAsync
- WaitForNetworkIdleAsync
- Evaluate
- requestEventListener
- responseEventListener
- Cleanup
- WaitForRequestAsync
- WaitForResponseAsync
- WaitForFileChooserAsync
- GoBackAsync
- GoForwardAsync
- SetBurstModeOffAsync
- BringToFrontAsync
- EmulateVisionDeficiencyAsync
- EmulateTimezoneAsync
- EmulateIdleStateAsync
- EmulateCPUThrottlingAsync
- OnPopup
- InitializeAsync
- GoAsync
- ClientMessageReceived
- OnDetachedFromTarget
- OnTargetCrashed
- EmitMetrics
- HandleException
- OnDialog
- Dispose
- DisposeAsync
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