private void Undo()
{
if (App.Model.UndoIndex + 1 == App.Model.Undos.Count)//如果是第一次撤销
{
//根据最后的一个撤销的类型，保留当前的状态为新的撤销类
Undo undo = new Undo();
switch (App.Model.Undos.Last().undeoType)
{
case UndeoType.Targe:
undo.TargeInstantiation(App.Model.Index, App.Model.CurrentRenderTarget);
break;
case UndeoType.Mask:
undo.MaskInstantiation(App.Model.MaskRenderTarget, App.Model.MaskAnimatedTarget);
break;
case UndeoType.Index:
undo.IndexInstantiation(App.Model.Index);
break;
case UndeoType.Collection:
undo.CollectionInstantiation(App.Model.Index, App.Model.Layers);
break;
//case UndeoTyte.LayerAdd :break;
//case UndeoTyte.LayerRemove :break;
case UndeoType.Visual:
undo.VisualInstantiation(App.Model.Index, App.Model.Layers[App.Model.Index].Visual);
break;
case UndeoType.Opacity:
undo.OpacityInstantiation(App.Model.Index, App.Model.Layers[App.Model.Index].Opacity);
break;
case UndeoType.Blend:
undo.BlendInstantiation(App.Model.Index, App.Model.Layers[App.Model.Index].BlendIndex);
break;
case UndeoType.Tool:
undo.ToolInstantiation(App.Model.Tool);
break;
default: break;
}
App.Model.Undos.Add(undo);
}
if (App.Model.Undos.Count > 2 && App.Model.UndoIndex >= 0)
{
App.Model.Undos[App.Model.UndoIndex].Perform(); //后退
App.Model.UndoIndex--; //撤销索引后退一步
App.Model.isRedo = true; //重做可用
}
else
{
App.Model.isUndo = false; //撤销不可用
}
}