C# 在Xamarin.Android中的OnMeasure override方法的单独布局中添加TextView时，不会呈现TextView

我有以下课程

TextLayout类，我在其中创建了一个textview，并将其添加到onMeasure override方法中

public class TextLayout : FrameLayout
{
    private TextView headerLabel;
    public TextLayout(Context context) : base(context)
    {

    }
    private void UpdateText()
    {
        if(headerLabel == null)
        this.headerLabel = new TextView(this.Context);
        headerLabel.LayoutParameters = (new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MatchParent, ViewGroup.LayoutParams.MatchParent));
        this.headerLabel.Text = "General Meeting";
        headerLabel.SetTextColor(Color.Green);
        headerLabel.Typeface = Typeface.DefaultBold;
        headerLabel.TextSize = 25;
    }

    protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
    {
        base.OnMeasure(widthMeasureSpec, heightMeasureSpec);
        UpdateText();
        int minimumWidth = this.PaddingLeft + PaddingRight + SuggestedMinimumWidth;
        int widthOfLayout = ResolveSizeAndState(minimumWidth, widthMeasureSpec, 1);
        SetMeasuredDimension(widthOfLayout, 75);
        if (this.headerLabel.Parent == null)
        {
            this.AddView(this.headerLabel);
        }
    }
}

我有另一个类作为中间类，我在这个中间类的OnMeasure方法中添加了TextLayout类，如下所示

public class IntermediateLayout : FrameLayout
{
    TextLayout textLayout;
    public IntermediateLayout(Context context) : base(context)
    {

    }

    protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
    {
        base.OnMeasure(widthMeasureSpec, heightMeasureSpec);
        if (textLayout == null)
            textLayout = new TextLayout(this.Context);
        this.AddView(textLayout);
    }
}

最后，在main类中，我在OnCreate的main类中添加了中间类

    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);

        IntermediateLayout mainLayout = new IntermediateLayout(this);

        // Set our view from the "main" layout resource
        SetContentView(mainLayout);
    }

在此场景中，textview不会呈现在Xamarin.Android平台中的视图中

同样在另一个场景中，当在中间类（定义了TextClass）的OnMeasure方法中设置TextLayout类的布局参数时，文本不会呈现在视图中。但当在同一类（TextLayout）的OnMeasure方法中设置布局参数时，文本会呈现在视图中

设置类的布局参数的正确方法是什么

有没有办法解决这个问题

设置类的布局参数的正确方法是什么

旨在确定视图的测量宽度和测量高度。初始化时或视图大小更改时，将多次调用它。因此，将一些初始化代码放在测量中不是一个好地方

在代码中，

this.AddView（textLayout）onMeasure

时，

IntermediateLayout

中的code>将导致异常

因此，放置视图初始化代码的好地方是类的构造函数：

TextLayout.cs:

public class TextLayout:FrameLayout
{
    private TextView headerLabel;
    public TextLayout(Context context) : base(context)
    {
        //put the initialization codes in contructor
            UpdateText();
            if (this.headerLabel.Parent == null)
            {
                this.AddView(this.headerLabel);
            }
    }


    private void UpdateText()
    {
        if (headerLabel == null)
            this.headerLabel = new TextView(this.Context);
        headerLabel.LayoutParameters = (new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MatchParent, ViewGroup.LayoutParams.MatchParent));
        this.headerLabel.Text = "General Meeting";
        headerLabel.SetTextColor(Color.Green);
        headerLabel.Typeface = Typeface.DefaultBold;
        headerLabel.TextSize = 25;
    }


    protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
    {
        base.OnMeasure(widthMeasureSpec, heightMeasureSpec);
        int minimumWidth = this.PaddingLeft + PaddingRight + SuggestedMinimumWidth;
        int widthOfLayout = ResolveSizeAndState(minimumWidth, widthMeasureSpec, 1);
        SetMeasuredDimension(widthOfLayout, 75);
    }
}

IntermediateLayout.cs：

public class IntermediateLayout : FrameLayout
{
    TextLayout textLayout;
    public IntermediateLayout(Context context) : base(context)
    {
        if (textLayout == null)
            textLayout = new TextLayout(this.Context);
        this.AddView(textLayout);
    }
    //there is no need to override onMeasured here
}