/// <summary>
/// Renders the specified HTML source on the specified location and max size restriction.<br/>
/// If <paramref name="maxSize"/>.Width is zero the html will use all the required width, otherwise it will perform line
/// wrap as specified in the html<br/>
/// If <paramref name="maxSize"/>.Height is zero the html will use all the required height, otherwise it will clip at the
/// given max height not rendering the html below it.<br/>
/// Returned is the actual width and height of the rendered html.<br/>
/// </summary>
/// <param name="g">Device to render with</param>
/// <param name="html">HTML source to render</param>
/// <param name="location">the top-left most location to start render the html at</param>
/// <param name="maxSize">the max size of the rendered html (if height above zero it will be clipped)</param>
/// <param name="cssData">optional: the style to use for html rendering (default - use W3 default style)</param>
/// <param name="useGdiPlusTextRendering">true - use GDI+ text rendering, false - use GDI text rendering</param>
/// <param name="stylesheetLoad">optional: can be used to overwrite stylesheet resolution logic</param>
/// <param name="imageLoad">optional: can be used to overwrite image resolution logic</param>
/// <returns>the actual size of the rendered html</returns>
private static SizeF RenderHtml(Graphics g, string html, PointF location, SizeF maxSize, CssData cssData, bool useGdiPlusTextRendering, EventHandler <HtmlStylesheetLoadEventArgs> stylesheetLoad, EventHandler <HtmlImageLoadEventArgs> imageLoad)
{
SizeF actualSize = SizeF.Empty;
if (!string.IsNullOrEmpty(html))
{
using (var container = new HtmlContainer())
{
container.Location = location;
container.MaxSize = maxSize;
container.AvoidAsyncImagesLoading = true;
container.AvoidImagesLateLoading = true;
if (stylesheetLoad != null)
{
container.StylesheetLoad += stylesheetLoad;
}
if (imageLoad != null)
{
container.ImageLoad += imageLoad;
}
container.SetHtml(html, cssData);
container.PerformLayout(g);
container.PerformPaint(g);
actualSize = container.ActualSize;
}
}
return(actualSize);
}
/// <summary>
/// Perform paint of the html in the control.
/// </summary>
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
if (_htmlContainer != null)
{
_htmlContainer.Location = new PointF(Padding.Left, Padding.Top);
_htmlContainer.PerformPaint(e.Graphics);
}
}
/// <summary>
/// Renders the specified HTML into a new image of unknown size that will be determined by min/max width/height and HTML layout.<br/>
/// If <paramref name="maxSize.Width"/> is zero the html will use all the required width, otherwise it will perform line
/// wrap as specified in the html<br/>
/// If <paramref name="maxSize.Height"/> is zero the html will use all the required height, otherwise it will clip at the
/// given max height not rendering the html below it.<br/>
/// If <paramref name="minSize"/> (Width/Height) is above zero the rendered image will not be smaller than the given min size.<br/>
/// The generated image have transparent background that the html is rendered on.<br/>
/// See "Rendering to image" remarks section on <see cref="HtmlRender"/>.<br/>
/// </summary>
/// <param name="html">HTML source to render</param>
/// <param name="minSize">optional: the min size of the rendered html (zero - not limit the width/height)</param>
/// <param name="maxSize">optional: the max size of the rendered html, if not zero and html cannot be layout within the limit it will be clipped (zero - not limit the width/height)</param>
/// <param name="cssData">optional: the style to use for html rendering (default - use W3 default style)</param>
/// <param name="stylesheetLoad">optional: can be used to overwrite stylesheet resolution logic</param>
/// <param name="imageLoad">optional: can be used to overwrite image resolution logic</param>
/// <returns>the generated image of the html</returns>
public static Image RenderToImage(string html, Size minSize, Size maxSize, CssData cssData = null,
EventHandler <HtmlStylesheetLoadEventArgs> stylesheetLoad = null, EventHandler <HtmlImageLoadEventArgs> imageLoad = null)
{
if (string.IsNullOrEmpty(html))
{
return(null);
}
using (var container = new HtmlContainer())
{
container.AvoidAsyncImagesLoading = true;
container.AvoidImagesLateLoading = true;
if (stylesheetLoad != null)
{
container.StylesheetLoad += stylesheetLoad;
}
if (imageLoad != null)
{
container.ImageLoad += imageLoad;
}
container.SetHtml(html, cssData);
var finalSize = MeasureHtmlByRestrictions(container, minSize, maxSize);
container.MaxSize = finalSize;
// create the final image to render into by measured size
var image = new Bitmap(finalSize.Width, finalSize.Height, PixelFormat.Format32bppRgba);
// render HTML into the image
using (var g = new Graphics(image))
{
container.PerformPaint(g);
}
return(image);
}
}