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我正在尝试从CATiledLayer.

根据此关闭的错误报告，设置CATiledLayer.FadeDuration静态属性不起作用也不应该这样做：https ://bugzilla.novell.com/show_bug.cgi?id=648993

Objective-C 中建议的解决方案是子类化CATiledLayer：How to change iphone CATiledLayer fadeDuration? . 我已经在 MonoTouch 中实现了这一点，但视图中没有绘制任何内容，尽管DrawInContext按预期调用。

重现该问题的完整代码如下。一旦我删除[Export("fadeDuration")]一切正常（但有动画）。

提前感谢您的帮助。

using System;
using System.Drawing;
using MonoTouch.CoreAnimation;
using MonoTouch.UIKit;
using MonoTouch.Foundation;
using MonoTouch.ObjCRuntime;

[Register("NoFadeTiledLayer")]
public class NoFadeTiledLayer : CATiledLayer {

 public NoFadeTiledLayer () : base() {}
 public NoFadeTiledLayer (IntPtr handle) : base(handle) {}

 public override void DrawInContext (MonoTouch.CoreGraphics.CGContext ctx) {
   // This is being called everytime
   base.DrawInContext (ctx); 
 }

 [Export("fadeDuration")]
 public static new double FadeDuration () {
  return 0;
 }
}

public class ContentView : UIView {

 [Export("layerClass")]
 public static Class LayerClass () {
  return new Class (typeof(NoFadeTiledLayer));
 }

 public override void Draw (RectangleF rect) {
  DrawString ("Lorem ipsum", rect, UIFont.SystemFontOfSize (15));
 }
}


[Register("AppDelegate")]
public class AppDelegate : UIApplicationDelegate {

 static void Main (string[] args) {
  UIApplication.Main (args, null, "AppDelegate");
 }

 public override bool FinishedLaunching (UIApplication app, NSDictionary options) {
  var window = new UIWindow (UIScreen.MainScreen.ApplicationFrame);
  window.BackgroundColor = UIColor.Green;
  var view = new ContentView ();
  view.BackgroundColor = UIColor.White;
  view.Frame = window.Bounds;
  window.AddSubview (view);
  window.MakeKeyAndVisible ();

  return true;
 }
}
4

1 回答 1

2

您没有保留对 UIWindow 的引用，这意味着它可以被收集和释放。

我像这样重写了你的课程：

using System;
using System.Drawing;
using MonoTouch.CoreAnimation;
using MonoTouch.UIKit;
using MonoTouch.Foundation;
using MonoTouch.ObjCRuntime;

namespace FadeTest
{
    [Register("NoFadeTiledLayer")]
    public class NoFadeTiledLayer : CATiledLayer
    {

        public NoFadeTiledLayer () : base()
        {
        }

        public NoFadeTiledLayer (IntPtr handle) : base(handle)
        {
        }

        public override void DrawInContext (MonoTouch.CoreGraphics.CGContext ctx)
        {
            // This is being called everytime
            base.DrawInContext (ctx); 
        }

        [Export("fadeDuration")]
        public static new double FadeDuration
        {
            get
            {
                return 0;
            }
        }
    }

    public class ContentView : UIView
    {

        [Export("layerClass")]
        public static Class LayerClass ()
        {
            return new Class (typeof(NoFadeTiledLayer));
        }

        public override void Draw (RectangleF rect)
        {
            DrawString ("Lorem ipsum", rect, UIFont.SystemFontOfSize (15));
        }
    }

    public partial class AppDelegate : UIApplicationDelegate
    {
        static void Main (string[] args)
        {
            UIApplication.Main (args, null, "AppDelegate");
        }

        public override bool FinishedLaunching (UIApplication app, NSDictionary options)
        {
            window = new UIWindow (UIScreen.MainScreen.ApplicationFrame);
            window.BackgroundColor = UIColor.Green;
            var view = new ContentView ();
            view.BackgroundColor = UIColor.White;
            view.Frame = window.Bounds;
            window.AddSubview (view);
            window.MakeKeyAndVisible ();

            return true;
        }
    }
}

并将其放置在基于窗口的项目的默认项目模板中，它按预期工作。

于 2011-01-27T19:33:17.727 回答