1

背景

我试图让任何视图显示下拉列表（不是对话框，而是显示在视图下方/上方的列表），如微调器所示（从 API 11 开始，如此处所示）。

为此，我使用来自 actionBarSherlock 库的 IcsListPopupWindow.java。

问题

我无法让它很好地显示项目列表：

  1. 当列表太大而无法显示时，列表不会显示（滚动条的）拇指。

  2. 选择项目时，有时会出现正常的选择效果，有时会出现很多灰色背景，如下图：

在此处输入图像描述

问题

我究竟做错了什么？我查看了 IcsListPopupWindow.java 的代码，很难理解和查看需要什么和不需要什么。

这是我的示例代码：

public class MainActivity extends Activity {

    private PopupMenuAdapter mAdapter;

    @Override
    protected void onCreate(final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //prepare popup menu:
        final PopupMenuItem[] items = new PopupMenuItem[10];
        for (int i = 0; i < items.length; ++i) 
            items[i] = new PopupMenuItem(android.R.drawable.sym_def_app_icon, R.string.hello_world);
        mAdapter = new PopupMenuAdapter(this, android.R.layout.simple_list_item_1, items);
        final IcsListPopupWindow popupWindow = new IcsListPopupWindow(this, null, R.attr.popupMenuStyle);       popupWindow.setBackgroundDrawable(getResources().getDrawable(R.drawable.abs__menu_dropdown_panel_holo_light));
        popupWindow.setAdapter(mAdapter);
        popupWindow.setModal(true);
        popupWindow.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(final AdapterView<?> arg0, final View arg1, final int arg2, final long arg3) {
                popupWindow.dismiss();
            }
        });
        //upon clicking on a button, show the popup menu :
        findViewById(R.id.button1).setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(final View v) {
                // show popup menu:
                popupWindow.setContentWidth(MainActivity.this.getWindowManager().getDefaultDisplay().getWidth() / 2);
                mAdapter.notifyDataSetChanged(); // if you change anything
                popupWindow.setAnchorView(v);
                popupWindow.show();
            }
        });
    }

    // //////////////////////////////////////////////////////////
    // PopupMenuAdapter //
    // ///////////////////
    private class PopupMenuAdapter extends ArrayAdapter<PopupMenuItem> {

        Context context;
        int layoutResourceId;
        PopupMenuItem data[] = null;

        public PopupMenuAdapter(final Context context, final int layoutResourceId, final PopupMenuItem[] data) {
            super(context, layoutResourceId, data);
            this.layoutResourceId = layoutResourceId;
            this.context = context;
            this.data = data;
        }

        @Override
        public View getView(final int position, final View convertView, final ViewGroup parent) {
            View view = convertView;
            if (view == null) {
                final LayoutInflater inflater = ((Activity) context).getLayoutInflater();
                view = inflater.inflate(layoutResourceId, parent, false);
            }
            final PopupMenuItem pItem = data[position];
            final TextView text = (TextView) view.findViewById(android.R.id.text1);
            text.setText(pItem.textResId);
            text.setCompoundDrawablesWithIntrinsicBounds(pItem.iconResId, 0, 0, 0);
            return view;
        }
    }

    private static class PopupMenuItem {
        public int iconResId;
        public int textResId;

        public PopupMenuItem(final int iconResId, final int textResId) {
            this.iconResId = iconResId;
            this.textResId = textResId;
        }
    }
}

编辑：我现在已经尝试了 HoloEverywhere 库中的 ListPopupWindow.java 文件（并且还只导入了它需要的文件），它也有完全相同的问题。

编辑：对于第二个问题（选择效果），我使用了我自己定制的 listView 项，它的根视图有一个 next 属性：

android:background="@android:drawable/list_selector_background"

仍然不知道如何显示滚动条。如果我使用：

mPopup.getListView().setVerticalScrollBarEnabled(true);
mPopup.getListView().setScrollbarFadingEnabled(false);

比 actionBarSherlock 什么都没有发生，而对于 holoEverywhere 我得到一个 NPE：

07-03 14:28:09.359: E/AndroidRuntime(1869): java.lang.NullPointerException
07-03 14:28:09.359: E/AndroidRuntime(1869):     at android.view.View.onDrawScrollBars(View.java:5976)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at android.view.View.draw(View.java:6939)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at android.widget.AbsListView.draw(AbsListView.java:3030)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at android.view.ViewGroup.drawChild(ViewGroup.java:1646)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1373)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at android.view.View.draw(View.java:6936)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at android.widget.FrameLayout.draw(FrameLayout.java:357)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at android.view.ViewRoot.draw(ViewRoot.java:1529)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at android.view.ViewRoot.performTraversals(ViewRoot.java:1265)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1867)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at android.os.Handler.dispatchMessage(Handler.java:99)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at android.os.Looper.loop(Looper.java:130)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at android.app.ActivityThread.main(ActivityThread.java:3687)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at java.lang.reflect.Method.invokeNative(Native Method)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at java.lang.reflect.Method.invoke(Method.java:507)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
07-03 14:28:09.359: E/AndroidRuntime(1869):     at dalvik.system.NativeStart.main(Native Method)
4

1 回答 1

0

与 HoloEverywhere 配合得很好：P 截屏

package org.holoeverywhere.dropdowntest;

import org.holoeverywhere.app.Activity;
import org.holoeverywhere.widget.ListPopupWindow;
import org.holoeverywhere.widget.TextView;

import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.BaseAdapter;

public class MainActivity extends Activity implements OnClickListener {
    private final class DummyAdapter extends BaseAdapter {
        @Override
        public int getCount() {
            return 500;
        }

        @Override
        public Object getItem(int position) {
            return position;
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            if (convertView == null) {
                convertView = getLayoutInflater().inflate(R.layout.item, parent, false);
            }
            ((TextView) convertView).setText("I'm dummy item #" + position);
            return convertView;
        }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        findViewById(R.id.halfSize).setOnClickListener(this);
        findViewById(R.id.fullSize).setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        ListPopupWindow lpw = new ListPopupWindow(this);
        lpw.setAdapter(new DummyAdapter());
        lpw.setAnchorView(v);
        int contentWidth = getResources().getDisplayMetrics().widthPixels;
        if (v.getId() == R.id.halfSize) {
            contentWidth /= 2;
        } else {
            // Hardcoded padding, i know
            contentWidth -= 20;
        }
        lpw.setContentWidth(contentWidth);
        lpw.show();
    }
}
于 2013-07-03T13:34:57.363 回答