[英]Check if Canvas Child exist: by tag
How can I can check by tag if a Canvas
child exists? 我如何通过标签检查
Canvas
子项是否存在?
For example I want to know if in my Canvas
(canvas1) there exists a child that has tag "p". 例如,我想知道在我的
Canvas
(canvas1)中是否存在一个带有标签“ p”的孩子。
How can I can check by tag if a canvas child exist?
我如何才能通过标签检查画布子项是否存在?
So I suppose a bool value is what you want 所以我想布尔值就是你想要的
bool result = mycanvas.Children.Cast<FrameworkElement>()
.Any(x => x.Tag != null && x.Tag.ToString() == "p");
I used (x.Tag == null ? "" : x.Tag.ToString()) == "p")
just to be sure that tag property is not null. 我使用
(x.Tag == null ? "" : x.Tag.ToString()) == "p")
只是为了确保tag属性不为null。
OR 要么
If you want the Element then 如果您想要元素,那么
FrameworkElement result = mycanvas.Children.Cast<FrameworkElement>()
.Where(x => x.Tag != null &&
x.Tag.ToString() == "p")
.First();
object mytag;
DrawingCanvas.Children.Select((elem) =>
{
FrameworkElement fe = elem as FrameworkElement;
if (fe != null)
{
return fe.Tag == mytag;
}
else
return false;
});
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