using System;
using System.Threading.Tasks;
using System.Windows.Forms;
using CefSharp;
using CefSharp.WinForms;

public class MyForm : Form
{
    private ChromiumWebBrowser browser;

    public MyForm()
    {
        InitializeComponent();
        InitializeBrowser();
    }

    private void InitializeComponent()
    {
        this.Text = "CefSharp Screenshot Example";
        this.Width = 800;
        this.Height = 600;
    }

    private void InitializeBrowser()
    {
        var settings = new CefSettings();
        Cef.Initialize(settings);
        browser = new ChromiumWebBrowser("https://example.com")
        {
            Dock = DockStyle.Fill
        };
        this.Controls.Add(browser);
    }

    private async Task TakeScreenshotAsync()
    {
        // 獲取頁面高度
        var pageHeight = await browser.EvaluateScriptAsync("document.body.scrollHeight");
        if (pageHeight.Success)
        {
            var height = (int)(long)pageHeight.Result;

            // 設置模擬裝置解析度
            await browser.GetDevToolsClient().Emulation.SetDeviceMetricsOverrideAsync(800, height, 1.0, true);

            // 截圖
            var screenshot = await browser.ScreenshotAsync();

            // 保存截圖
            screenshot.Save("screenshot.png");

            // 清除設備度量
            await browser.GetDevToolsClient().Emulation.ClearDeviceMetricsOverrideAsync();
        }
    }

    protected override async void OnLoad(EventArgs e)
    {
        base.OnLoad(e);
        await Task.Delay(2000); // 等待頁面加載完成
        await TakeScreenshotAsync();
    }

    protected override void OnFormClosing(FormClosingEventArgs e)
    {
        Cef.Shutdown();
        base.OnFormClosing(e);
    }

    [STAThread]
    static void Main()
    {
        Application.EnableVisualStyles();
        Application.Run(new MyForm());
    }
}