php结合c#实现后台网页(无需打开浏览器)截图
项目中有时需要根据url来获取这个页面的截图,怎么办呢,php还没有办法截图,php暂时还没办法后台对网页截图,但是c#可以在命令行中调用cefsharp进行网页截图,然后返回给php进行调用
c#主要代码如下,新建一个console项目,引入cefsharp,这里有教程怎么引入cefsharp http://blog.bfw.wiki/user6/15572101669805510054.html
主要用到的方法就是ScreenshotAsync
using System; using System.Diagnostics; using System.IO; using System.Threading; using CefSharp.OffScreen; using System.Threading.Tasks; namespace CefSharp.bfw.OffScreen { public class Program { private static ChromiumWebBrowser browser; public static void Main(string[] args) { const string testUrl = "https://www.baidu.com/"; Console.WriteLine("This example application will load {0}, take a screenshot, and save it to your desktop.", testUrl); Console.WriteLine("You may see Chromium debugging output, please wait..."); Console.WriteLine(); //Monitor parent process exit and close subprocesses if parent process exits first //This will at some point in the future becomes the default CefSharpSettings.SubprocessExitIfParentProcessClosed = true; var settings = new CefSettings() { //By default CefSharp will use an in-memory cache, you need to specify a Cache Folder to persist data CachePath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "CefSharp\\Cache") }; //Perform dependency check to make sure all relevant resources are in our output directory. Cef.Initialize(settings, performDependencyCheck: true, browserProcessHandler: null); // Create the offscreen Chromium browser. browser = new ChromiumWebBrowser(testUrl); // An event that is fired when the first page is finished loading. // This returns to us from another thread. browser.LoadingStateChanged += BrowserLoadingStateChanged; // We have to wait for something, otherwise the process will exit too soon. Console.ReadKey(); // Clean up Chromium objects. You need to call this in your application otherwise // you will get a crash when closing. Cef.Shutdown(); } private static void BrowserLoadingStateChanged(object sender, LoadingStateChangedEventArgs e) { // Check to see if loading is complete - this event is called twice, one when loading starts // second time when it's finished // (rather than an iframe within the main frame). if (!e.IsLoading) { // Remove the load event handler, because we only want one snapshot of the initial page. browser.LoadingStateChanged -= BrowserLoadingStateChanged; var scriptTask = browser.EvaluateScriptAsync("document.getElementById('lst-ib').value = 'CefSharp Was Here!'"); scriptTask.ContinueWith(t => { //Give the browser a little time to render Thread.Sleep(500); // Wait for the screenshot to be taken. var task = browser.ScreenshotAsync(); task.ContinueWith(x => { // Make a file to save it to (e.g. C:\Users\jan\Desktop\CefSharp screenshot.png) var screenshotPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "CefSharp screenshot.png"); Console.WriteLine(); Console.WriteLine("Screenshot ready. Saving to {0}", screenshotPath); // Save the Bitmap to the path. // The image type is auto-detected via the ".png" extension. task.Result.Save(screenshotPath); // We no longer need the Bitmap. // Dispose it to avoid keeping the memory alive. Especially important in 32-bit applications. task.Result.Dispose(); Console.WriteLine("Screenshot saved. Launching your default image viewer..."); // Tell Windows to launch the saved image. Process.Start(new ProcessStartInfo(screenshotPath) { // UseShellExecute is false by default on .NET Core. UseShellExecute = true }); Console.WriteLine("Image viewer launched. Press any key to exit."); }, TaskScheduler.Default); }); } } } }
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