如何在WPF中克隆畫布

Question

美好的一天。我嘗試創建圖形編輯器（如Paint）。所以，我需要創建「撤消」和「重做」按鈕。如果我複製畫布的兒童，Canvas.Children包含很多項目時需要太多時間。如何實現撤消和重做操作？

Answer 1

我從來沒有使用過Canvas但克隆它，我想這和它似乎工作：

Canvas canvas = new Canvas(); 
canvas.Background = Brushes.Thistle; 

Canvas clonedCanvas = ElementClone<Canvas>(canvas); 
Brush clonedBrush = clonedCanvas.Background; 

/// <summary> 
/// Clones an element. 
/// </summary> 
public static T ElementClone<T>(T element) 
{ 
    T clone = default(T); 
    MemoryStream memStream = ElementToStream(element); 
    clone = ElementFromStream<T>(memStream); 
    return clone; 
} 

/// <summary> 
/// Saves an element as MemoryStream. 
/// </summary> 
public static MemoryStream ElementToStream(object element) 
{ 
    MemoryStream memStream = new MemoryStream(); 
    XamlWriter.Save(element, memStream); 
    return memStream; 
} 

/// <summary> 
/// Rebuilds an element from a MemoryStream. 
/// </summary> 
public static T ElementFromStream<T>(MemoryStream elementAsStream) 
{ 
    object reconstructedElement = null; 

    if (elementAsStream.CanRead) 
    { 
     elementAsStream.Seek(0, SeekOrigin.Begin); 
     reconstructedElement = XamlReader.Load(elementAsStream); 
     elementAsStream.Close(); 
    } 

    return (T)reconstructedElement; 
}