/// <summary>
/// Renders the specified HTML into a new image of the requested size.<br/>
/// The HTML will be layout by the given size but will be clipped if cannot fit.<br/>
/// <p>
/// Limitation: The image cannot have transparent background, by default it will be white.<br/>
/// See "Rendering to image" remarks section on <see cref="HtmlRender"/>.<br/>
/// </p>
/// </summary>
/// <param name="html">HTML source to render</param>
/// <param name="size">The size of the image to render into, layout html by width and clipped by height</param>
/// <param name="backgroundColor">optional: the color to fill the image with (default - white)</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>
/// <exception cref="ArgumentOutOfRangeException">if <paramref name="backgroundColor"/> is <see cref="Color.Transparent"/></exception>.
public static Image RenderToImage(string html, Size size, Color backgroundColor = new Color(), CssData cssData = null,
EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null, EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
{
if (backgroundColor == Color.Transparent)
throw new ArgumentOutOfRangeException("backgroundColor", "Transparent background in not supported");
// create the final image to render into
var image = new Bitmap(size.Width, size.Height, PixelFormat.Format32bppArgb);
if (!string.IsNullOrEmpty(html))
{
// create memory buffer from desktop handle that supports alpha channel
IntPtr dib;
var memoryHdc = Win32Utils.CreateMemoryHdc(IntPtr.Zero, image.Width, image.Height, out dib);
try
{
// create memory buffer graphics to use for HTML rendering
using (var memoryGraphics = Graphics.FromHdc(memoryHdc))
{
memoryGraphics.Clear(backgroundColor != Color.Empty ? backgroundColor : Color.White);
// render HTML into the memory buffer
RenderHtml(memoryGraphics, html, PointF.Empty, size, cssData, true, stylesheetLoad, imageLoad);
}
// copy from memory buffer to image
CopyBufferToImage(memoryHdc, image);
}
finally
{
Win32Utils.ReleaseMemoryHdc(memoryHdc, dib);
}
}
return image;
}
/// <summary>
/// Renders the specified HTML on top of the given image.<br/>
/// <paramref name="image"/> will contain the rendered html in it on top of original content.<br/>
/// <paramref name="image"/> must not contain transparent pixels as it will corrupt the rendered html text.<br/>
/// The HTML will be layout by the given image size but may be clipped if cannot fit.<br/>
/// See "Rendering to image" remarks section on <see cref="HtmlRender"/>.<br/>
/// </summary>
/// <param name="image">the image to render the html on</param>
/// <param name="html">HTML source to render</param>
/// <param name="location">optional: the top-left most location to start render the html at (default - 0,0)</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>
public static void RenderToImage(Image image, string html, PointF location = new PointF(), CssData cssData = null,
EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null, EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
{
ArgChecker.AssertArgNotNull(image, "image");
var maxSize = new SizeF(image.Size.Width - location.X, image.Size.Height - location.Y);
RenderToImage(image, html, location, maxSize, cssData, stylesheetLoad, imageLoad);
}
/// <summary>
/// Renders the specified HTML on top of the given image.<br/>
/// <paramref name="image"/> will contain the rendered html in it on top of original content.<br/>
/// <paramref name="image"/> must not contain transparent pixels as it will corrupt the rendered html text.<br/>
/// See "Rendering to image" remarks section on <see cref="HtmlRender"/>.<br/>
/// </summary>
/// <param name="image">the image to render the html on</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="stylesheetLoad">optional: can be used to overwrite stylesheet resolution logic</param>
/// <param name="imageLoad">optional: can be used to overwrite image resolution logic</param>
public static void RenderToImage(Image image, string html, PointF location, SizeF maxSize, CssData cssData = null,
EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null, EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
{
ArgChecker.AssertArgNotNull(image, "image");
if (!string.IsNullOrEmpty(html))
{
// create memory buffer from desktop handle that supports alpha channel
IntPtr dib;
var memoryHdc = Win32Utils.CreateMemoryHdc(IntPtr.Zero, image.Width, image.Height, out dib);
try
{
// create memory buffer graphics to use for HTML rendering
using (var memoryGraphics = Graphics.FromHdc(memoryHdc))
{
// draw the image to the memory buffer to be the background of the rendered html
memoryGraphics.DrawImageUnscaled(image, 0, 0);
// render HTML into the memory buffer
RenderHtml(memoryGraphics, html, location, maxSize, cssData, false, stylesheetLoad, imageLoad);
}
// copy from memory buffer to image
CopyBufferToImage(memoryHdc, image);
}
finally
{
Win32Utils.ReleaseMemoryHdc(memoryHdc, dib);
}
}
}
/// <summary>
/// Renders the specified HTML source on the specified location and max width restriction.<br/>
/// Use GDI text rendering, note <see cref="Graphics.TextRenderingHint"/> has no effect.<br/>
/// If <paramref name="maxWidth"/> is zero the html will use all the required width, otherwise it will perform line
/// wrap as specified in the html<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="left">optional: the left most location to start render the html at (default - 0)</param>
/// <param name="top">optional: the top most location to start render the html at (default - 0)</param>
/// <param name="maxWidth">optional: bound the width of the html to render in (default - 0, unlimited)</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 actual size of the rendered html</returns>
public static SizeF Render(Graphics g, string html, float left = 0, float top = 0, float maxWidth = 0, CssData cssData = null,
EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null, EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
{
ArgChecker.AssertArgNotNull(g, "g");
return RenderClip(g, html, new PointF(left, top), new SizeF(maxWidth, 0), cssData, false, stylesheetLoad, imageLoad);
}
/// <summary>
/// Renders the specified HTML source on the specified location and max size restriction.<br/>
/// Use GDI text rendering, note <see cref="Graphics.TextRenderingHint"/> has no effect.<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="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>
public static SizeF Render(Graphics g, string html, PointF location, SizeF maxSize, CssData cssData = null,
EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null, EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
{
ArgChecker.AssertArgNotNull(g, "g");
return RenderClip(g, html, location, maxSize, cssData, false, stylesheetLoad, imageLoad);
}
/// <summary>
/// Create deep copy of the css data with cloned css blocks.
/// </summary>
/// <returns>cloned object</returns>
public CssData Clone()
{
var clone = new CssData();
foreach (var mid in _mediaBlocks)
{
var cloneMid = new Dictionary<string, List<CssBlock>>(StringComparer.InvariantCultureIgnoreCase);
foreach (var blocks in mid.Value)
{
var cloneList = new List<CssBlock>();
foreach (var cssBlock in blocks.Value)
{
cloneList.Add(cssBlock.Clone());
}
cloneMid[blocks.Key] = cloneList;
}
clone._mediaBlocks[mid.Key] = cloneMid;
}
return clone;
}
/// <summary>
/// Measure the size (width and height) required to draw the given html under given max width restriction.<br/>
/// If no max width restriction is given the layout will use the maximum possible width required by the content,
/// it can be the longest text line or full image width.<br/>
/// Use GDI text rendering, note <see cref="Graphics.TextRenderingHint"/> has no effect.
/// </summary>
/// <param name="g">Device to use for measure</param>
/// <param name="html">HTML source to render</param>
/// <param name="maxWidth">optional: bound the width of the html to render in (default - 0, unlimited)</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 size required for the html</returns>
public static SizeF Measure(Graphics g, string html, float maxWidth = 0, CssData cssData = null,
EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null, EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
{
ArgChecker.AssertArgNotNull(g, "g");
return Measure(g, html, maxWidth, cssData, false, stylesheetLoad, imageLoad);
}
/// <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/>
/// GDI+ text rending can be controlled by providing <see cref="TextRenderingHint"/>.<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="textRenderingHint">optional: (default - SingleBitPerPixelGridFit)</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 RenderToImageGdiPlus(string html, Size minSize, Size maxSize, TextRenderingHint textRenderingHint = TextRenderingHint.AntiAlias, CssData cssData = null,
EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null, EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
{
if (string.IsNullOrEmpty(html))
return new Bitmap(0, 0, PixelFormat.Format32bppArgb);
using (var container = new HtmlContainer())
{
container.AvoidAsyncImagesLoading = true;
container.AvoidImagesLateLoading = true;
container.UseGdiPlusTextRendering = 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.Format32bppArgb);
// render HTML into the image
using (var g = Graphics.FromImage(image))
{
g.TextRenderingHint = textRenderingHint;
container.PerformPaint(g);
}
return image;
}
}
/// <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/>
/// Clip the graphics so the html will not be rendered outside the max height bound given.<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 RenderClip(Graphics g, string html, PointF location, SizeF maxSize, CssData cssData, bool useGdiPlusTextRendering, EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad, EventHandler<HtmlImageLoadEventArgs> imageLoad)
{
Region prevClip = null;
if (maxSize.Height > 0)
{
prevClip = g.Clip;
g.SetClip(new RectangleF(location, maxSize));
}
var actualSize = RenderHtml(g, html, location, maxSize, cssData, useGdiPlusTextRendering, stylesheetLoad, imageLoad);
if (prevClip != null)
{
g.SetClip(prevClip, CombineMode.Replace);
}
return actualSize;
}
/// <summary>
/// Renders the specified HTML into a new image of the requested size.<br/>
/// The HTML will be layout by the given size but will be clipped if cannot fit.<br/>
/// The generated image have transparent background that the html is rendered on.<br/>
/// GDI+ text rending can be controlled by providing <see cref="TextRenderingHint"/>.<br/>
/// See "Rendering to image" remarks section on <see cref="HtmlRender"/>.<br/>
/// </summary>
/// <param name="html">HTML source to render</param>
/// <param name="size">The size of the image to render into, layout html by width and clipped by height</param>
/// <param name="textRenderingHint">optional: (default - SingleBitPerPixelGridFit)</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 RenderToImageGdiPlus(string html, Size size, TextRenderingHint textRenderingHint = TextRenderingHint.AntiAlias, CssData cssData = null,
EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null, EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
{
var image = new Bitmap(size.Width, size.Height, PixelFormat.Format32bppArgb);
using (var g = Graphics.FromImage(image))
{
g.TextRenderingHint = textRenderingHint;
RenderHtml(g, html, PointF.Empty, size, cssData, true, stylesheetLoad, imageLoad);
}
return image;
}
/// <summary>
/// Renders the specified HTML into a new image of unknown size that will be determined by max width/height and HTML layout.<br/>
/// If <paramref name="maxWidth"/> 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="maxHeight"/> 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/>
/// The generated image have transparent background that the html is rendered on.<br/>
/// GDI+ text rending can be controlled by providing <see cref="TextRenderingHint"/>.<br/>
/// See "Rendering to image" remarks section on <see cref="HtmlRender"/>.<br/>
/// </summary>
/// <param name="html">HTML source to render</param>
/// <param name="maxWidth">optional: the max width of the rendered html, if not zero and html cannot be layout within the limit it will be clipped</param>
/// <param name="maxHeight">optional: the max height of the rendered html, if not zero and html cannot be layout within the limit it will be clipped</param>
/// <param name="textRenderingHint">optional: (default - SingleBitPerPixelGridFit)</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 RenderToImageGdiPlus(string html, int maxWidth = 0, int maxHeight = 0, TextRenderingHint textRenderingHint = TextRenderingHint.AntiAlias, CssData cssData = null,
EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null, EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
{
return RenderToImageGdiPlus(html, Size.Empty, new Size(maxWidth, maxHeight), textRenderingHint, cssData, stylesheetLoad, imageLoad);
}
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
/// </summary>
private void Dispose(bool all)
{
try
{
if (all)
{
LinkClicked = null;
Refresh = null;
RenderError = null;
StylesheetLoad = null;
ImageLoad = null;
}
_cssData = null;
if (_root != null)
_root.Dispose();
_root = null;
if (_selectionHandler != null)
_selectionHandler.Dispose();
_selectionHandler = null;
}
catch
{ }
}
/// <summary>
/// Init with optional document and stylesheet.
/// </summary>
/// <param name="htmlSource">the html to init with, init empty if not given</param>
/// <param name="baseCssData">optional: the stylesheet to init with, init default if not given</param>
public void SetHtml(string htmlSource, CssData baseCssData = null)
{
Clear();
if (!string.IsNullOrEmpty(htmlSource))
{
_cssData = baseCssData ?? _adapter.DefaultCssData;
DomParser parser = new DomParser(_cssParser);
_root = parser.GenerateCssTree(htmlSource, this, ref _cssData);
if (_root != null)
{
_selectionHandler = new SelectionHandler(_root);
}
}
}
/// <summary>
/// Combine this CSS data blocks with <paramref name="other"/> CSS blocks for each media.<br/>
/// Merge blocks if exists in both.
/// </summary>
/// <param name="other">the CSS data to combine with</param>
public void Combine(CssData other)
{
ArgChecker.AssertArgNotNull(other, "other");
// for each media block
foreach (var mediaBlock in other.MediaBlocks)
{
// for each css class in the media block
foreach (var bla in mediaBlock.Value)
{
// for each css block of the css class
foreach (var cssBlock in bla.Value)
{
// combine with this
AddCssBlock(mediaBlock.Key, cssBlock);
}
}
}
}
/// <summary>
/// Renders the specified HTML into a new image of unknown size that will be determined by max width/height and HTML layout.<br/>
/// If <paramref name="maxWidth"/> 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="maxHeight"/> 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/>
/// <p>
/// Limitation: The image cannot have transparent background, by default it will be white.<br/>
/// See "Rendering to image" remarks section on <see cref="HtmlRender"/>.<br/>
/// </p>
/// </summary>
/// <param name="html">HTML source to render</param>
/// <param name="maxWidth">optional: the max width of the rendered html, if not zero and html cannot be layout within the limit it will be clipped</param>
/// <param name="maxHeight">optional: the max height of the rendered html, if not zero and html cannot be layout within the limit it will be clipped</param>
/// <param name="backgroundColor">optional: the color to fill the image with (default - white)</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>
/// <exception cref="ArgumentOutOfRangeException">if <paramref name="backgroundColor"/> is <see cref="Color.Transparent"/></exception>.
public static Image RenderToImage(string html, int maxWidth = 0, int maxHeight = 0, Color backgroundColor = new Color(), CssData cssData = null,
EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null, EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
{
return RenderToImage(html, Size.Empty, new Size(maxWidth, maxHeight), backgroundColor, cssData, stylesheetLoad, imageLoad);
}
/// <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;
container.UseGdiPlusTextRendering = useGdiPlusTextRendering;
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>
/// 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/>
/// <p>
/// Limitation: The image cannot have transparent background, by default it will be white.<br/>
/// See "Rendering to image" remarks section on <see cref="HtmlRender"/>.<br/>
/// </p>
/// </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="backgroundColor">optional: the color to fill the image with (default - white)</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>
/// <exception cref="ArgumentOutOfRangeException">if <paramref name="backgroundColor"/> is <see cref="Color.Transparent"/></exception>.
public static Image RenderToImage(string html, Size minSize, Size maxSize, Color backgroundColor = new Color(), CssData cssData = null,
EventHandler<HtmlStylesheetLoadEventArgs> stylesheetLoad = null, EventHandler<HtmlImageLoadEventArgs> imageLoad = null)
{
if (backgroundColor == Color.Transparent)
throw new ArgumentOutOfRangeException("backgroundColor", "Transparent background in not supported");
if (string.IsNullOrEmpty(html))
return new Bitmap(0, 0, PixelFormat.Format32bppArgb);
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.Format32bppArgb);
// create memory buffer from desktop handle that supports alpha channel
IntPtr dib;
var memoryHdc = Win32Utils.CreateMemoryHdc(IntPtr.Zero, image.Width, image.Height, out dib);
try
{
// render HTML into the memory buffer
using (var memoryGraphics = Graphics.FromHdc(memoryHdc))
{
memoryGraphics.Clear(backgroundColor != Color.Empty ? backgroundColor : Color.White);
container.PerformPaint(memoryGraphics);
}
// copy from memory buffer to image
CopyBufferToImage(memoryHdc, image);
}
finally
{
Win32Utils.ReleaseMemoryHdc(memoryHdc, dib);
}
return image;
}
}
/// <summary>
/// Init with optional document and stylesheet.
/// </summary>
/// <param name="htmlSource">the html to init with, init empty if not given</param>
/// <param name="baseCssData">optional: the stylesheet to init with, init default if not given</param>
public void SetHtml(string htmlSource, CssData baseCssData = null)
{
_htmlContainerInt.SetHtml(htmlSource, baseCssData);
}
