作者:军军CJJ_317 | 来源:互联网 | 2023-05-18 06:15
最近在找C#根据URL生成缩略图的相关资料,转载如下哪位仁兄有这方面的源码或开发经验请赐教,本人不胜感激我的邮箱zxjyuan@163.com原理是通过IE在本地打开目标URL同时截图,
最近在找C#根据URL生成缩略图的相关资料,转载如下
哪位仁兄有这方面的源码或开发经验请赐教,本人不胜感激
我的邮箱zxjyuan@163.com
原理是通过IE在本地打开目标URL同时截图,
这种方法都有安全性的问题,如果你为恶意网页生成缩略图,可能就是一场灾难……
private void OnDocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
{
WebBrowser browser = (sender as WebBrowser);
if (browser != null)
{
mshtml.IHTMLDocument2 document = (browser.Document.DomDocument as mshtml.IHTMLDocument2);
if (document != null)
{
mshtml.IHTMLElement element = (document.body as mshtml.IHTMLElement);
if (element != null)
{
IHTMLElementRender render = (element as IHTMLElementRender);
if (render != null)
{
using (Graphics graphics = this.CreateGraphics())
{
IntPtr hdcDestination = graphics.GetHdc();
render.DrawToDC(hdcDestination);
IntPtr hdcMemory = GDI32.CreateCompatibleDC(hdcDestination);
IntPtr bitmap = GDI32.CreateCompatibleBitmap(
hdcDestination,
browser.ClientRectangle.Width,
browser.ClientRectangle.Height
);
if (bitmap != IntPtr.Zero)
{
IntPtr hOld = (IntPtr)GDI32.SelectObject(hdcMemory, bitmap);
GDI32.BitBlt(
hdcMemory,
0, 0,
browser.ClientRectangle.Width, browser.ClientRectangle.Height,
hdcDestination,
0, 0,
TernaryRasterOperations.SRCCOPY
);
GDI32.SelectObject(hdcMemory, hOld);
GDI32.DeleteDC(hdcMemory);
graphics.ReleaseHdc(hdcDestination);
SaveThumbnail(Image.FromHbitmap(bitmap));
}
}
}
}
}
}
}
从这里获取了内容的话,我们就很容易生成缩略图了,代码如下
//by crazycoder.cn
private void SaveThumbnail(Image image)
{
if (image != null)
{//创建一个位图图像
Bitmap thumbnail = new Bitmap(160, 120, PixelFormat.Format24bppRgb);
thumbnail.SetResolution(image.HorizontalResolution, image.VerticalResolution);
using (Graphics resize = Graphics.FromImage(thumbnail))
{
resize.InterpolatiOnMode= InterpolationMode.HighQualityBicubic;
resize.DrawImage(image,
new Rectangle(0, 0, 160, 120),
new Rectangle(0, 0, _webBrowser.ClientRectangle.Width, _webBrowser.ClientRectangle.Height),
GraphicsUnit.Pixel);
}
thumbnail.Save(_file.FullName, ImageFormat.Png);
}
}
下载整个项目代码 CrazyCoder_WebPageToImage.zip
附:做得比较好的在线生成缩略图的网站
http://www.wenwenba.com/
http://www.websnapr.com/
http://mozshot.nemui.org/
http://webthumb.bluga.net/home