Question

我正在尝试以编程方式将imageViews添加到Custom RelativeLayout。问题是由于某种原因，自定义RelativeLayout的childViews不可见。我做错了什么？

public class MyViewGroup extends RelativeLayout{

    Context mContext;

    public MyViewGroup(Context context) {
        super(context);

        mContext = context;

        init();
    }

    public MyViewGroup(Context context, AttributeSet attrs) {
        super(context, attrs);

        mContext = context;
        init();
    }

    public MyViewGroup(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        mContext = context;
        init();
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {

    }

    void init()
    {
        for(int i=0; i<2; i++)
        {
            ImageView myImage = new ImageView(mContext);

            if(i==0)
                myImage.setBackgroundColor(Color.CYAN);
            else
                myImage.setBackgroundColor(Color.MAGENTA);


            myImage.setId(i);

            RelativeLayout.LayoutParams params= new LayoutParams(50+i*70, 50+i*70);
            myImage.setLayoutParams(params);


            ImageView sImage = new ImageView(mContext);

            if(i==0)
            sImage.setBackgroundColor(Color.RED);
            else
                sImage.setBackgroundColor(Color.GREEN);


            RelativeLayout.LayoutParams p= new LayoutParams(200+i*70, 200+i*70);
            p.addRule(RelativeLayout.ALIGN_TOP | RelativeLayout.ALIGN_LEFT, myImage.getId());
            sImage.setLayoutParams(p);

            addView(myImage);
            addView(sImage);

        }

    }
}

内部布局file.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

    <TextView android:text="@string/hello_world" android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <user.com.MyViewGroup
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        />

</RelativeLayout>

我错过了什么？

最好的问候

编辑：

        RelativeLayout.LayoutParams params= new LayoutParams(200+i*70, 200+i*70);
        params.addRule(RelativeLayout.CENTER_IN_PARENT);
        myImage.setLayoutParams(params);


        ImageView sImage = new ImageView(mContext);

        sImage.setBackgroundColor(Color.RED);


        RelativeLayout.LayoutParams p= new LayoutParams(20+i*70, 20+i*70);
        p.addRule(RelativeLayout.CENTER_IN_PARENT);
        p.addRule(RelativeLayout.ALIGN_BOTTOM, myImage.getId());
        sImage.setLayoutParams(p);

        addView(myImage);
        addView(sImage);

Answer 1

您错过了致电super.onLayout(changed, l, t, r, b);，@Override protected void onLayout(boolean changed, int l, int t, int r, int b) { }负责为其子女分配职位。在ViewGroup的具体实现中，如果默认实现对您来说足够，则可以避免重写此方法。如果您决定扩展ViewGroup，则必须提供实现，因为它被声明为abstract。在你的情况下你可以摆脱

{{1}}

自定义视图不可见

1 个答案: