Question

我是Xamarin monoandroid的新手，我在向我的布局添加自定义视图时遇到了问题。我不知道我做错了什么。很少的帮助将是完整的，这是我的自定义视图类

onDraw方法被调用，但我没有得到输出，也没有错误。

class PositionDrawer : View
    {
        private int count;
        private int position;
        private IPositionDrawer cinterface;
        private Activity cactivity;
        private int container;
        private int p;
        private ScoreFeed scoreFeed1;
        private ScoreFeed scoreFeed2;
        public PositionDrawer(Activity context, int count, int positionr, Activity cactivity) :
            base (context)
        {
            //Initialize ();
            this.cactivity = cactivity;
            this.cinterface = cinterface;
            this.count = count;
            this.position = positionr;
            //this.OnDraw();
            Initialize();
        }

        private void Initialize()
        {
            //this.Invalidate();
           // this.SetMeasuredDimension(100, 100);
            this.SetWillNotDraw(false);
            Console.WriteLine(this.WillNotDraw());
        }
        protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
        {
            base.OnMeasure(widthMeasureSpec, heightMeasureSpec);
        }
        public void SetDrawer(int count, int positionr, Activity cactivity)

        {

           this.cactivity = cactivity;
           this.cinterface = cinterface;
           this.count = count;
           this.position = positionr;

           //base(cactivity);   
        }

         protected override void OnDraw(Canvas canvas)
        {
            base.OnDraw(canvas);
            Paint blue = new Paint();
            blue.Color = Color.Red;

            float screenwidth = cactivity.WindowManager.DefaultDisplay.Width;
            canvas.DrawRect(screenwidth * position-1, 0, screenwidth * position, 20, blue);
            Console.WriteLine("SW1:" + screenwidth + "pos1:" + position);
           // LinearLayout can =cactivity.FindViewById<LinearLayout>(container);
            //cinterface.getview(this);
        }

    }

我使用以下代码将视图添加到布局中。

 View pd = new PositionDrawer(this, 3, position, this);
 container = FindViewById<LinearLayout>(Resource.Id.position);
 container.RemoveAllViews();
 container.AddView(pd);

提前谢谢。

Answer 1

您需要实施正确的ctors。

当您实施View课程时，您必须至少拥有具有以下签名的ctor：

public PositionDrawer(IntPtr javaReference, JniHandleOwnership transfer)
    : base(javaReference, transfer) { }

如果您在View布局中使用AXML，则还需要具有以下签名的那个：

public PositionDrawer(Context context, IAttributeSet attrs, int defStyle)
    : base(context, attrs, defStyle)

否则，当您从代码创建View时，您需要向他们提供一些LayoutParameters，否则他们不知道自己的大小。

Xamarin Android自定义视图未加载

1 个答案: