android - 冲突的 Android 错误消息 : The specified child already has a parent. 您必须先对 child 的 parent 调用 removeView()

Question

最初我得到这个错误:

The specified child already has a parent. You must call removeView() on the child's parent first

在

customSection.addView(customLayout);

所以我加了

((LinearLayout)customLayout.getParent()).removeView(customLayout);

现在得到

java.lang.NullPointerException

如果 child 有 parent ，我必须先从 parent 那里删除 child ，为什么 getParent() 返回 null？

我有一个抽象 fragment ，允许派生类为列表适配器提供自定义布局。相关代码:

绑定(bind):

public void bind(DataObject row) {
    View customLayout = getChildItemView(row);
    if (customLayout != null) {
        ((LinearLayout) customLayout.getParent()).removeView(customLayout);
        customSection.removeAllViews();
        customSection.addView(customLayout);
        customSection.setVisibility(View.VISIBLE);
    } else {
        customLayout.setVisibility(View.INVISIBLE);
    }

}

protected View getChildItemView(CommonRow row) {
    if (parentView == null) {
        parentView = (LinearLayout) LayoutInflater.from(getActivity())
                .inflate(R.layout.list_item_custom_section,
                        new LinearLayout(getActivity()), true);
        label = (TextView) parentView.findViewById(R.id.txtData1Label);
        value = (TextView) parentView.findViewById(R.id.txtData1Value);
    }
    label.setText("Minimum");
    value.setText(manager.formatMoney(((SpecificDataRow) row).minimum));
    return parentView;
}

我也尝试过 inflater.inflate(R.layout.list_item_custom_section, null) ... false, null/false, 什么给了？

编辑:

@allprog，我知道需要进行一些清理。我在一天结束时写了这篇文章，有点匆忙。从那以后，我清理了代码，并分离出 View 的绑定(bind)和膨胀。清理代码:

private class ViewHolder {
....

       public ViewHolder(View v) {
            Butterknife.inject(this, v);
            View custom = createCustomView(customSection);
            if (custom != null) {
                customSection.setVisibility(View.VISIBLE);
                customSection.addView(custom);
            }
        }

        public void bind(CommonRow row) {
            ......

            bindCustomView(row, customSection);
        }

}

子类:

    @Override
    protected View createCustomView(ViewGroup parent) {
        return LayoutInflater.from(getActivity()).inflate(R.layout.list_item_custom_section, parent, false);
    }


    @Override
    protected void bindCustomView(CommonRow row, ViewGroup section) {
        TextView label = Views.findById(section, R.id.txtData1Label);
        TextView value = Views.findById(section, R.id.txtData1Value);

        label.setText("Minimum");
        value.setText(manager.formatMoney(((SpecificRow) row).minimum));
    }

suitianshi 首先得到它，用我原来的 [undempt] 代码就是解决方案。

Answer 1

试试这个:

public void bind(DataObject row) {
    View customLayout = getChildItemView(row);
    if (customLayout != null) {
         if(customLayout.getParent() != null) {
             ((LinearLayout)customLayout.getParent()).removeView(customLayout);
         }

         customSection.removeAllViews();
         customSection.addView(customLayout);
         customSection.setVisibility(View.VISIBLE);
    } else {
         customLayout.setVisibility(View.INVISIBLE);
    }

}

我已经阅读了相关的源代码，当view 有parent 时，getParent 应该返回非空值。在转换和调用 removeView

之前，您应该 确保它确实有父级

希望这对您有所帮助。

源代码:

在 View 中:

public final ViewParent getParent() {
        return mParent;
    }

在 ViewGroup.addViewInner

if (child.getParent() != null) {
     throw new IllegalStateException("The specified child already has a parent. " +
         "You must call removeView() on the child's parent first.");
}