![](/img/trans.png)
[英]How to dispose memory of the UIbutton from the UIScrollview in xamarin.ios
[英]How to override LayoutSublayersOfLayer behavior of Xamarin.IOS UIButton?
我正在移植到Xamarin.IOS一个快速的库,用UIButton制作一些材料设计动画。
swift对应物是UIButton的子类,并覆盖layoutSublayersOfLayer。
迅速:
public override func layoutSublayersOfLayer(layer: CALayer) {
super.layoutSublayersOfLayer(layer)
if self.layer == layer {
layoutShape()
layoutVisualLayer()
}
}
在Xamarin方面,我注意到这个方法是通过CALayerDelegate调用的,它通过de property Delegate与CALayer相关联。 我尝试子类CALayerDelegate并替换de Delegate属性,但是当我这样做时,按钮没有正确呈现并停止响应事件。
有没有办法在Xamarin.Ios上覆盖layoutSublayersOfLayer? 在绘制特定图层之前,是否有其他方法可以覆盖以准备内容?
public class MaterialButtonLayerDelegate : CALayerDelegate
{
private readonly MaterialButton _button;
public MaterialButtonLayerDelegate(MaterialButton button):base()
{
_button = button;
}
public override void LayoutSublayersOfLayer(CALayer layer)
{
if (_button.Layer == layer)
{
_button.LayoutShape();
_button.LayoutVisualLayer();
}
}
}
[Register("MaterialButton")]
public class MaterialButton : UIButton
{
public CAShapeLayer VisualLayer { get; private set; } = new CAShapeLayer();
public MaterialButton(CGRect frame):base(frame)
{
PrepareView();
}
protected void PrepareView()
{
Layer.Delegate = new MaterialButtonLayerDelegate(this);
ContentScaleFactor = MaterialDevice.Scale();
PrepareVisualLayer();
}
protected virtual void PrepareVisualLayer()
{
VisualLayer.ZPosition = 0;
VisualLayer.MasksToBounds = true;
Layer.AddSublayer(VisualLayer);
}
protected virtual void LayoutShape()
{
//...
}
protected virtual void LayoutVisualLayer()
{
//...
}
}
谢谢!
唯一可行的方法是扩展CALayerDelegate类并将其设置为CAShapeLayer委托。 请务必尽可能调用委托的基本成员,因为它在幕后执行所需的绑定。
public override void LayoutSublayersOfLayer(CALayer layer)
{
base.LayoutSublayersOfLayer(layer);
if (_button.Layer == layer)
{
_button.LayoutShape();
_button.LayoutVisualLayer();
}
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.