保存呈現比屏幕上顯示的大的UIElement的圖像

Question

我有一個圖表顯示給用戶，我希望能夠將圖表作爲圖像導出到磁盤，以便他們可以在應用程序（用於演示文稿或其他內容）。

我設法得到了使用PngBitmapEncoder和RenderTargetBitmap的基本思想，但我從中得到的圖像是小到真正可用的圖像，我希望獲得更大的圖像。

我試圖簡單地增加我想渲染的控件的高度和寬度，但父級似乎直接控制渲染大小。從這裏我嘗試在內存中複製UIElement，但是渲染大小是（0,0），當我嘗試使用方法來渲染它時，例如Measure（）Arrange（）和UpdateLayout（），它們會拋出異常需要解耦父對象來調用這些對象，但是因爲它在內存中並且不會被渲染，所以不應該有父對象？

這是所有Visiblox圖表API來完成

以下是我已經有了目前，只是它不工作:(

var width = 1600; 
var height = 1200; 

var newChart = new Chart { Width = width, Height = height, Title = chart.Title, XAxis = chart.XAxis, YAxis = chart.YAxis, Series = chart.Series}; 
Debug.WriteLine(newChart.RenderSize); 
var size = new Size(width, height); 
newChart.Measure(size); 
newChart.Arrange(new Rect(size)); 
newChart.UpdateLayout(); 
Debug.WriteLine(newChart.RenderSize); 

var rtb = new RenderTargetBitmap(width, height, 96, 96, PixelFormats.Pbgra32); 
      rtb.Render(newChart); 

var encoder = new PngBitmapEncoder(); 
encoder.Frames.Add(BitmapFrame.Create(rtb)); 

using (var stream = fileDialog.OpenFile()) 
    encoder.Save(stream); 

我現在已經變得有點接近，它渲染圖形背景軸等，但只是沒有正在繪製的實際線下面是一個更新的源

public static void RenderChartToImage(Chart elementToRender, string filename) 
{ 
    if (elementToRender == null) 
     return; 
    Debug.Write(elementToRender.RenderSize); 
    var clone = new Chart(); 

    clone.Width = clone.Height = double.NaN; 
    clone.HorizontalAlignment = HorizontalAlignment.Stretch; 
    clone.VerticalAlignment = VerticalAlignment.Stretch; 
    clone.Margin = new Thickness(); 

    clone.Title = elementToRender.Title; 
    clone.XAxis = new DateTimeAxis(); 
    clone.YAxis = new LinearAxis() { Range = Range<double>)elementToRender.YAxis.Range}; 

    foreach (var series in elementToRender.Series) 
    { 
     var lineSeries = new LineSeries 
          { 
           LineStroke = (series as LineSeries).LineStroke, 
           DataSeries = series.DataSeries 
          }; 
     clone.Series.Add(lineSeries); 
    } 


    var size = new Size(1600, 1200); 

    clone.Measure(size); 
    clone.Arrange(new Rect(size)); 
    clone.UpdateLayout(); 

    Debug.Write(clone.RenderSize); 

    var height = (int)clone.ActualHeight; 
    var width = (int)clone.ActualWidth; 

    var renderer = new RenderTargetBitmap(width, height, 96d, 96d, PixelFormats.Pbgra32); 

    renderer.Render(clone); 

    var pngEncoder = new PngBitmapEncoder(); 
    pngEncoder.Frames.Add(BitmapFrame.Create(renderer)); 

    using (var file = File.Create(filename)) 
    { 
     pngEncoder.Save(file); 
    } 
} 

於是我走出這樣的：。

哪個大，沒有用，因爲它沒有任何圖表。

Answer 1

http://www.visiblox.com/blog/2011/05/printing-visiblox-charts

主要的一點，我缺少的是

InvalidationHandler.ForceImmediateInvalidate = true; 

設置此之前我渲染內存圖表，然後恢復它一旦我完成了。從那裏它是光滑的航行：D

Answer 2

我覺得這可能會幫助：

Exporting Visifire Silverlight Chart as Image與下載silverlight solution。

Exporting Chart as Image in WPF

Answer 3

RenderTargetBitmap DrawToImage<T>(T source, double scale) where T:FrameworkElement 
{ 
    var clone = Clone(source); 
    clone.Width = clone.Height = Double.NaN; 
    clone.HorizontalAlignment = System.Windows.HorizontalAlignment.Stretch; 
    clone.VerticalAlignment = System.Windows.VerticalAlignment.Stretch; 
    clone.Margin = new Thickness(); 
    var size = new Size(source.ActualWidth * scale, source.ActualHeight * scale); 
    clone.Measure(size); 
    clone.Arrange(new Rect(size)); 

    var renderBitmap = new RenderTargetBitmap((int)clone.ActualWidth, (int)clone.ActualHeight, 96, 96, PixelFormats.Pbgra32); 
    renderBitmap.Render(clone); 
    return renderBitmap; 
} 

static T Clone<T>(T source) where T:UIElement 
{ 
    if (source == null) 
     return null; 
    string xaml = XamlWriter.Save(source); 
    var reader = new StringReader(xaml); 
    var xmlReader = XmlTextReader.Create(reader, new XmlReaderSettings()); 
    return (T)XamlReader.Load(xmlReader); 
}