如何从 LinearLayout 中删除所有 LinearLayouts?

How to delete all LinearLayouts from a LinearLayout?

我正在以编程方式创建大量 LinearLayout 并将它们放在另一个 LinearLayout 上:

public void loadList(){
    LinearLayout linearLayout = (LinearLayout)findViewById(R.id.linearShowing);

    if(linearLayout.getChildCount() > 0)
        linearLayout.removeAllViews(); // THIS LINE DOESN'T WORK FOR LINEARLAYOUTS INSIDE LINEARLAYOUTS

    List<Mineral> showMineralsList = dbHandler.getAllMinerais("external");

    for (Mineral mineral : showMineralsList){
        id = mineral.getID();
        //testIds.add(id);
        int favorite = mineral.getFavorite();
        String nome = mineral.getName(),
                formulaQuimica = mineral.getFormulaQuimica();

        LinearLayout linearVertical = new LinearLayout(this);
        linearVertical.setOrientation(LinearLayout.VERTICAL);
        LinearLayout.LayoutParams lvParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
        linearVertical.setLayoutParams(lvParams);

        LinearLayout linearHorizontalOuter = new LinearLayout(this);
        linearHorizontalOuter.setOrientation(LinearLayout.HORIZONTAL);
        LinearLayout.LayoutParams lhoParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
        lhoParams.gravity = Gravity.CENTER_VERTICAL;
        linearHorizontalOuter.setLayoutParams(lhoParams);

        LinearLayout linearHorizontalInner = new LinearLayout(this);
        linearHorizontalInner.setOrientation(LinearLayout.HORIZONTAL);
        LinearLayout.LayoutParams lhiParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT, 1.0f);
        lhiParams.gravity = Gravity.CENTER_VERTICAL;
        linearHorizontalInner.setLayoutParams(lhiParams);

        ImageButton ibStar = new ImageButton(this);
        LinearLayout.LayoutParams ibsParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
        ibsParams.setMargins(0, 0, vinteMargin, 0);
        ibStar.setLayoutParams(ibsParams);
        if(favorite == 0)
            ibStar.setBackgroundResource(R.drawable.ic_star_gray_24dp);
        else
            ibStar.setBackgroundResource(R.drawable.ic_star_blue_24dp);
        vId = generateViewId();
        vIds.put(vId, id);
        linearHorizontalInner.setId(vId);

        linearHorizontalInner.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                i = new Intent(Main.this, Detalhes.class);
                i.putExtra("id", vIds.get(view.getId()));
                startActivity(i);
            }
        });

        vId = generateViewId();
        vIds.put(vId, id);
        ibStar.setId(vId);
        ibStar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                setFavorite(vIds.get(view.getId()));
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

        TextView tvName = new TextView(this);
        LinearLayout.LayoutParams tvnParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT, 1.0f);
        tvName.setText(nome);
        tvName.setLayoutParams(tvnParams);
        tvName.setTextSize(TypedValue.COMPLEX_UNIT_SP, 17);

        TextView tvFormula = new TextView(this);
        LinearLayout.LayoutParams tvfParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.MATCH_PARENT, 1.0f);
        tvFormula.setText(formulaQuimica);
        tvFormula.setLayoutParams(tvfParams);
        tvFormula.setTextSize(TypedValue.COMPLEX_UNIT_SP, 17);

        TableLayout.LayoutParams lpDiv = new TableLayout.LayoutParams(TableLayout.LayoutParams.MATCH_PARENT, TableLayout.LayoutParams.WRAP_CONTENT, 5f);
        lpDiv.setMargins(0, dezMargin, 0, dezMargin);

        ImageView ivDiv = new ImageView(this);
        ivDiv.setBackgroundResource(R.drawable.divider);
        ivDiv.setLayoutParams(lpDiv);

        linearHorizontalInner.addView(tvName);
        linearHorizontalInner.addView(tvFormula);

        linearHorizontalOuter.addView(ibStar);
        linearHorizontalOuter.addView(linearHorizontalInner);

        linearVertical.addView(ivDiv);
        linearVertical.addView(linearHorizontalOuter);

        linearLayout.addView(linearVertical);
    }
}

有时,在我的 Activity 中,我必须重新加载该列表...所以我试图从 "linearLayout" 中删除所有视图(我的主要布局设置在 XML布局文件)使用 linearLayout.removeAllViews();,但它抛出我:

java.lang.IllegalArgumentException: No suitable parent found from the given view. Please provide a valid view.

我已经通过执行以下操作解决了这个问题:

  • 正在为我的 "linearVertical" 设置一个 ID(对应于我的主要 parent LinearLayout 的第一个 child);
  • 每次创建新的 linearVertical 时将此 ID 添加到列表中;
  • 迭代此列表并将在该列表中具有其 ID 的所有视图的可见性设置为 GONE。

代码:

private ArrayList<Integer> layoutsIds = new ArrayList<>();

public void loadList(){
    resetViews();
    (...)
    (...)
    layoutId = generateViewId();
    linearVertical.setId(layoutId);
    layoutsIds.add(layoutId);
    (...)
    (...)
}

public void resetViews(){
    for(int a=0; a<layoutIds.size(); a++){
        LinearLayout toRemove = (LinearLayout)findViewById(layoutIds.get(a));
        toRemove.setVisibility(View.GONE);
    }
}

当然这可以改进,但是,基本上,这是我的解决方案(:

试试这个代码

if(linearLayout.getChildCount() > 0)
        linearLayout.removeAllViews();