C# TouchMove事件在xamarin ios中结束得如此之快
我创建了一个画布视图,如下所示。当我把它应用到一个新项目中时,它工作正常,但当我把它应用到我的实际项目中时,我不能画一条实线。它总是虚线(如下图所示)。第一次,我认为这是一个问题,因为我推了太多的屏幕,直到这个绘图。但每次我推送一个新视图时,我都试图禁用前一个视图的用户交互,但它不起作用。请帮忙C# TouchMove事件在xamarin ios中结束得如此之快,c#,.net,swift,xamarin,C#,.net,Swift,Xamarin,我创建了一个画布视图,如下所示。当我把它应用到一个新项目中时,它工作正常,但当我把它应用到我的实际项目中时,我不能画一条实线。它总是虚线(如下图所示)。第一次,我认为这是一个问题,因为我推了太多的屏幕,直到这个绘图。但每次我推送一个新视图时,我都试图禁用前一个视图的用户交互,但它不起作用。请帮忙 public class CanvasView : UIView { public CanvasView (CGRect frame) : base(frame) { t
public class CanvasView : UIView
{
public CanvasView (CGRect frame) : base(frame)
{
this.drawPath = new CGPath();
BackgroundColor = UIColor.White;
}
private CGPoint touchLocation;
private CGPoint previousTouchLocation;
private CGPath drawPath;
private bool fingerDraw;
public override void LayoutSubviews ()
{
base.LayoutSubviews ();
Layer.BorderWidth = 0.5f;
Layer.BorderColor = UIColor.FromRGB (146, 146, 146).CGColor;
}
public override void TouchesBegan (NSSet touches, UIEvent evt)
{
base.TouchesBegan (touches, evt);
UITouch touch = touches.AnyObject as UITouch;
this.fingerDraw = true;
this.touchLocation = touch.LocationInView(this);
this.previousTouchLocation = touch.PreviousLocationInView(this);
this.SetNeedsDisplay();
}
public override void TouchesMoved (NSSet touches, UIEvent evt)
{
base.TouchesMoved (touches, evt);
UITouch touch = touches.AnyObject as UITouch;
this.touchLocation = touch.LocationInView(this);
this.previousTouchLocation = touch.PreviousLocationInView(this);
this.SetNeedsDisplay();
}
public override void TouchesEnded (NSSet touches, UIEvent evt)
{
base.TouchesEnded (touches, evt);
var alert = new UIAlertView () {
Message = "Xui"
};
alert.AddButton("OK");
alert.Show();
}
public override void Draw (CGRect rect)
{
base.Draw (rect);
if (this.fingerDraw)
{
using (CGContext context = UIGraphics.GetCurrentContext())
{
context.SetStrokeColor(UIColor.Black.CGColor);
context.SetLineWidth(1.5f);
context.SetLineJoin(CGLineJoin.Round);
context.SetLineCap(CGLineCap.Round);
this.drawPath.MoveToPoint(this.previousTouchLocation);
this.drawPath.AddLineToPoint(this.touchLocation);
context.AddPath(this.drawPath);
context.DrawPath(CGPathDrawingMode.Stroke);
}
}
}
}
我认为问题不在于
触摸移动
,而在于您的绘图逻辑。当你调用SetNeedsDisplay()
时,它并不意味着“现在绘制”,而是意味着“我有需要绘制的更改,所以亲爱的,在你可以的时候绘制我。”这意味着在处理绘图之前,会有更多的接触
在接到
Draw
调用之前,您必须保持上一个点不变,或者您必须将这些点放入缓冲区,并同时绘制它们。我会做第一个,因为它更简单。但我不知道它在另一个项目上是如何工作的?请给我更多的细节!我试着按照你的建议去做,但还是这样:(