/// <summary>
/// Asynchronously returns an <see cref="Image"/> that represents a screenshot
/// of the specified <see cref="Control"/> as it appears on the browser.
/// </summary>
/// <param name="target">
/// The <see cref="Control"/> to render to an <see cref="Image"/>
/// </param>
/// <param name="options">The <see cref="Html2CanvasOptions"/> to pass to the html2canvas call.</param>
/// <returns>An awaitable <see cref="Task"/> that contains the screenshot.</returns>
public static Task <Image> ScreenshotAsync(Control target, Html2CanvasOptions options = null)
{
if (target == null)
{
throw new ArgumentNullException(nameof(target));
}
var tcs = new TaskCompletionSource <Image>();
Instance.ScreenshotCore(target, options, (result) => {
if (result is Exception)
{
tcs.SetException((Exception)result);
}
else if (result is Image)
{
tcs.SetResult((Image)result);
}
else
{
tcs.SetResult(null);
}
});
return(tcs.Task);
}
/// <summary>
/// Takes a screenshot of the specified <see cref="Control"/>.
/// </summary>
/// <param name="target">
/// The <see cref="Control"/> to render to an <see cref="Image"/>
/// </param>
/// <param name="callback">Callback method that receives the <see cref="Image"/> object.</param>
/// <param name="options">The <see cref="Html2CanvasOptions"/> to pass to the html2canvas call.</param>
/// <exception cref="ArgumentNullException">If any of the arguments is null.</exception>
public static void Screenshot(Control target, Html2CanvasOptions options, Action <Image> callback)
{
if (target == null)
{
throw new ArgumentNullException(nameof(target));
}
if (options == null)
{
throw new ArgumentNullException(nameof(options));
}
if (callback == null)
{
throw new ArgumentNullException(nameof(callback));
}
Instance.ScreenshotCore(target, options, (result) => {
if (result is Exception)
{
throw (Exception)result;
}
else
{
callback(result as Image);
}
});
}
/// <summary>
/// Asynchronously returns an <see cref="Image"/> that represents a screenshot
/// of the browser.
/// </summary>
/// <param name="options">The <see cref="Html2CanvasOptions"/> to pass to the html2canvas call.</param>
/// <returns>An awaitable <see cref="Task"/> that contains the screenshot.</returns>
public static Task <Image> ScreenshotAsync(Html2CanvasOptions options = null)
{
var tcs = new TaskCompletionSource <Image>();
Instance.ScreenshotCore(null, options, (image) => {
tcs.SetResult(image);
});
return(tcs.Task);
}
/// <summary>
/// Takes a screenshot of the browser.
/// </summary>
/// <param name="options">The <see cref="Html2CanvasOptions"/> to pass to the html2canvas call.</param>
/// <param name="callback">Callback method that receives the <see cref="Image"/> object.</param>
/// <exception cref="ArgumentNullException">If any of the arguments is null.</exception>
public static void Screenshot(Html2CanvasOptions options, Action <Image> callback)
{
if (options == null)
{
throw new ArgumentNullException(nameof(options));
}
if (callback == null)
{
throw new ArgumentNullException(nameof(callback));
}
Instance.ScreenshotCore(null, options, callback);
}
// Implementation
private void ScreenshotCore(Control target, Html2CanvasOptions options, Action <object> callback)
{
Call("screenshot",
(result) =>
{
if (result is string)
{
result = ImageFromBase64((string)result);
}
callback(result);
},
new object[] { target, options });
}
/// <summary>
/// Asynchronously returns an <see cref="Image"/> that represents a screenshot
/// of the browser.
/// </summary>
/// <param name="options">The <see cref="Html2CanvasOptions"/> to pass to the html2canvas call.</param>
/// <returns>An awaitable <see cref="Task"/> that contains the screenshot.</returns>
public static Task <Image> ScreenshotAsync(Html2CanvasOptions options = null)
{
var tcs = new TaskCompletionSource <Image>();
Instance.ScreenshotCore(null, options, (result) => {
if (result is Exception)
{
tcs.SetException((Exception)result);
}
else
{
tcs.SetResult(result as Image);
}
});
return(tcs.Task);
}
// Implementation
private void ScreenshotCore(Control target, Html2CanvasOptions options, Action <Image> callback)
{
var handle = (IntPtr)GCHandle.Alloc(callback, GCHandleType.Weak);
Call("screenshot", target, options, handle.ToInt64());
}
