android - LayoutInflater 为什么从 xml 返回原始 View 的副本以及如何从 xml 获取原始 View

Question

我想从 xml 文件获取一个 View 到普通类，我使用了 LayoutInflater，但它只给我这个 View 的副本而不是原始 View (我想设置对元素的更改)。

是否可以从 xml 获取原始布局？我该如何解决？

我想在其中获取布局的类

    public class Board  {
        private Context context;
       private View inflated;
      private RelativeLayout screen;

        public Board(Context context) {
           LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            inflated = inflater.inflate(R.layout.board, null);

             screen = (RelativeLayout) inflated.findViewById(R.id.custom_board_screen);
            this.context = context;
        }

        public TrippleToggleButton getButton(int id) {
            //return (TrippleToggleButton) inflated.findViewById(id);
            TrippleToggleButton btn;
            for(int i=0;i<screen.getChildCount();i++)
            {
                View v1 = screen.getChildAt(i);
                if(v1 instanceof TableLayout)
                {
                    for(int j=0;j<((TableLayout) v1).getChildCount();j++)
                    {
                        View v2 = ((TableLayout) v1).getChildAt(j);
                        if (v2 instanceof TableRow)
                        {
                            for(int k=0;k<((TableRow) v2).getChildCount();k++)
                            {
                                View v3 = ((TableRow) v2).getChildAt(k);
                                if (v3 instanceof TrippleToggleButton)
                                {
                                    Log.i("2014.07.10",screen.getId()+" ; "+v3.getId());
//originally id of button are 0-8; inflated 9 - 17
                                    if (v3.getId()==id) return (TrippleToggleButton)v3;
                                }
                            }
                        }
                    }
                }
            }
            return null;
        }
    }

XML文件:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/custom_board_screen"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TableLayout
        android:id="@+id/custom_board_table"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true">

        <TableRow
            android:id="@+id/custom_board_table_row1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">

            <board.TrippleToggleButton
                />
            <View style="@style/DividingVerticalLine"/>
            <View style="@style/DividingHorizontalLine"/>
            <board.TrippleToggleButton
                />
            <View style="@style/DividingVerticalLine"/>
            <board.TrippleToggleButton
                />
        </TableRow>
        <TableRow
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="#ff000000">
            <View style="@style/DividingHorizontalLine"/>
         </TableRow>

        <TableRow
            android:id="@+id/custom_board_table_row2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">

            <board.TrippleToggleButton
                />
            <View style="@style/DividingVerticalLine"/>
            <View style="@style/DividingHorizontalLine"/>
            <board.TrippleToggleButton
               />
            <View style="@style/DividingVerticalLine"/>
            <board.TrippleToggleButton
                />
        </TableRow>
        <TableRow
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="#ff000000">
            <View style="@style/DividingHorizontalLine"/>
        </TableRow>

        <TableRow
            android:id="@+id/custom_board_table_row3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">

            <board.TrippleToggleButton
               />
            <View style="@style/DividingVerticalLine"/>
            <View style="@style/DividingHorizontalLine"/>
            <board.TrippleToggleButton
                />
            <View style="@style/DividingVerticalLine"/>
            <board.TrippleToggleButton
                />
        </TableRow>




    </TableLayout>

</RelativeLayout>

我的自定义按钮类:

public class TrippleToggleButton extends Button implements View.OnClickListener {
    private Sign actual_state;
    private final float scale = getContext().getResources().getDisplayMetrics().density;
    private int dps = 50;
    private int pixels = (int) (dps * scale + 0.5f);
    private static int buttonCount = 0;

    public TrippleToggleButton(Context context) {
        this(context, null);
    }

    public TrippleToggleButton(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public TrippleToggleButton(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        addFeatures();
    }

    private void addFeatures() {
        actual_state = Sign.UNCHECKED;
        setOnClickListener(this);
        ViewGroup.LayoutParams param = new ViewGroup.LayoutParams(pixels, pixels);
        setLayoutParams(param);
        setGravity(Gravity.CENTER_HORIZONTAL | Gravity.CENTER_VERTICAL);
        setMinimumHeight(pixels);
        setMinimumWidth(pixels);
        setMinHeight(pixels * 2);
        setMinWidth(pixels * 2);
        setPadding(pixels / 10, pixels / 10, pixels / 10, pixels / 10);
        setTextSize(pixels);
        setId(IDAllocator.getNextID()); // this is just a static method which sets ID's starting from 0
    }

    private void onUncheckedState() {

    }

    public Sign getActual_state() {
        return actual_state;
    }

    public boolean isUnchecked() {
        return getActual_state() == Sign.UNCHECKED;
    }

    public void setState(Sign newState) {
        actual_state = newState;
        setText(actual_state.toString());
        setClickable(false);
    }

    @Override
    public void onClick(View v) {
        TrippleToggleButton btn = (TrippleToggleButton) v;

        if (btn.isUnchecked()) {
            Toast t = Toast.makeText(getContext(),""+getId(),Toast.LENGTH_SHORT); // it shows correct ID, everything goes ok here
            t.show();
           Container.performAction(btn);

        }
    }
}

Answer 1

从 xml 的角度来看，没有“原始”。 xml 描述一个布局，它并不是字面上的布局层次结构。每当您扩充 xml 时，扩充器都会使用 xml 作为构建新布局层次结构的指南，您可以引用它。如果您想更新那个原始的膨胀 View ，请将该原始引用传递给您的 Board 类并在那里执行更改，而不是再次膨胀整个事物。