Question

我刚刚获得了ExpandableListView设置，到目前为止一切正常。在组/父组件上，我有一个TextView和Button。列表的目的是让人们对应用程序中包含的不同声音进行采样，然后单击按钮，声音将保存到SD卡中。这是我到目前为止的链接：http://imgur.com/djSCIrG

我的问题是，在有人点击按钮并选择购买包之后是否可能只隐藏一个按钮而不是每个组中的所有按钮。

这是我的主要布局（expandablelistview_main.xml）：

<?xml version="1.0" encoding="utf-8"?>
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" >

        <TextView
            android:id="@+id/soundpacktitle"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="@dimen/expandablelistview_main_soundpacktitle_topmargin"
            android:layout_centerHorizontal="true"
            android:text="@string/soundpacktitle"
            android:textSize="@dimen/expandablelistview_main_soundpacktitle_textsize" />

        <ExpandableListView 
            android:id="@+id/soundpacklist" 
            android:layout_width="fill_parent"
            android:layout_height="0dp"
            android:layout_below="@+id/soundpacktitle"
            android:layout_above="@+id/soundpackbottombar"
            android:layout_marginTop="@dimen/expandablelistview_main_soundpacklist_topmargin"
            android:transcriptMode="disabled"
            android:cacheColorHint="#00000000"
            android:listSelector="@android:color/transparent" />   
    </RelativeLayout>

这是我的组/父布局（expandablelistview_group.xml）：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="?android:attr/listPreferredItemHeight"
    android:orientation="horizontal" >

    <TextView
        android:id="@+id/grouptextview"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:gravity="center_vertical"
        android:layout_marginLeft="@dimen/expandablelistview_group_grouptextview_leftmargin"        
        android:textSize="@dimen/expandablelistview_group_grouptextview_textsize" />

    <Button
        android:id="@+id/buypackbutton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center_vertical"
        android:layout_alignParentRight="true" 
        android:focusable="false" 
        android:focusableInTouchMode="false"
        android:text="@string/buypack"
        android:padding="@dimen/expandablelistview_group_buypackbutton_padding"
        android:textSize="@dimen/expandablelistview_group_buypackbutton_textsize"
        android:textStyle="bold" />

</RelativeLayout>

这是我的java类：

public class InAppSounds extends Activity {
    private ExpandableListView soundpacklist;

    private ArrayList<String> groups;
    private ArrayList<ArrayList<ArrayList<String>>> childs;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.expandablelistview_main);

        TextView soundpacktitle = (TextView) findViewById(R.id.soundpacktitle);
        soundpacktitle.setTypeface(printbold);

        // Declare the ExpandableListView and set's the indicator to the list arrows
        soundpacklist = (ExpandableListView) findViewById(R.id.soundpacklist);
        soundpacklist.setGroupIndicator(getResources().getDrawable(R.drawable.list_groupselector));

        LoadData();

        myExpandableAdapter adapter = new myExpandableAdapter(this, groups, childs);
        soundpacklist.setAdapter(adapter);
    }

    // Loads the ExpandableListView with parent and children groups
    private void LoadData() {
        groups = new ArrayList<String>();
        childs = new ArrayList<ArrayList<ArrayList<String>>>();

        // String array that stores the parent and child names
        String[] soundpackgroups = getResources().getStringArray(R.array.soundpackgroups);
        String[] soundpack1 = getResources().getStringArray(R.array.soundpack1);
        String[] soundpack2 = getResources().getStringArray(R.array.soundpack2);
        String[] soundpack3 = getResources().getStringArray(R.array.soundpack3);

        // First Sound Pack and their songs
        groups.add(soundpackgroups[0]);
        childs.add(new ArrayList<ArrayList<String>>());
        for (int a = 0; a < soundpack1.length; a++) {
            childs.get(0).add(new ArrayList<String>());
            childs.get(0).get(a).add(soundpack1[a]);
        }

        // Second Sound Pack and their songs
        groups.add(soundpackgroups[1]);
        childs.add(new ArrayList<ArrayList<String>>());
        for (int a = 0; a < soundpack2.length; a++) {
            childs.get(1).add(new ArrayList<String>());
            childs.get(1).get(a).add(soundpack2[a]);
        }

        // Third Sound Pack and their songs
        groups.add(soundpackgroups[2]);
        childs.add(new ArrayList<ArrayList<String>>());
        for (int a = 0; a < soundpack3.length; a++) {
            childs.get(2).add(new ArrayList<String>());
            childs.get(2).get(a).add(soundpack3[a]);
        }
    }

    public class myExpandableAdapter extends BaseExpandableListAdapter {

        private final ArrayList<String> groups;

        private final ArrayList<ArrayList<ArrayList<String>>> children;

        private final Context context;

        public myExpandableAdapter(Context context, ArrayList<String> groups,
                ArrayList<ArrayList<ArrayList<String>>> children) {
            this.context = context;
            this.groups = groups;
            this.children = childs;
        }

        @Override
        public boolean areAllItemsEnabled() {
            return true;
        }

        @Override
        public ArrayList<String> getChild(int groupPosition, int childPosition) {
            return children.get(groupPosition).get(childPosition);
        }

        @Override
        public long getChildId(int groupPosition, int childPosition) {
            return childPosition;
        }

        @Override
        public View getChildView(int groupPosition, final int childPosition,
                boolean isLastChild, View convertView, ViewGroup parent) {

            String child = getChild(groupPosition, childPosition).get(0);

            if (convertView == null) {
                LayoutInflater infalInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                convertView = infalInflater.inflate(R.layout.expandablelistview_child, null);
            }

            // TypeFace variable for the PrintBold
            printbold = Typeface.createFromAsset(getAssets(), "fonts/PrintBold.otf");

            TextView childtxt = (TextView) convertView.findViewById(R.id.childtextview);
            childtxt.setTypeface(printbold);
            childtxt.setText(child);

            return convertView;
        }

        @Override
        public int getChildrenCount(int groupPosition) {
            return children.get(groupPosition).size();
        }

        @Override
        public String getGroup(int groupPosition) {
            return groups.get(groupPosition);
        }

        @Override
        public int getGroupCount() {
            return groups.size();
        }

        @Override
        public long getGroupId(int groupPosition) {
            return groupPosition;
        }

        @Override
        public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {

            final String group = getGroup(groupPosition);

            if (convertView == null) {
                LayoutInflater infalInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                convertView = infalInflater.inflate(R.layout.expandablelistview_group, null);
            }

            // TypeFace variable for the PrintBold
            printbold = Typeface.createFromAsset(getAssets(), "fonts/PrintBold.otf");

            TextView grouptxt = (TextView) convertView.findViewById(R.id.grouptextview);
            grouptxt.setTypeface(printbold);
            grouptxt.setText(group);

            final Button buypackbutton = (Button) convertView.findViewById(R.id.buypackbutton);
            buypackbutton.setClickable(true);

            buypackbutton.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View view) {
                    AlertDialog.Builder alert = new AlertDialog.Builder(InAppSounds.this);
                    if (group.equals("Pack #1")) {
                        alert.setCancelable(false);
                        alert.setTitle(getString(R.string.buypacktitle));
                        alert.setIcon(getResources().getDrawable(R.drawable.ic_audioicon));
                        alert.setMessage(getString(R.string.buypackmsg));
                        alert.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                // check to make sure the SD card is mounted
                                // if not display an AlertDialog
                                if (!isSDPresent()) {
                                    sdcardalert();
                                }
                                else {
                                    // this will erase the button in all the groups, not just this group
                                    buypackbutton.setVisibility(View.INVISIBLE);
                                }
                            }
                        });
                        alert.setNegativeButton("No", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                dialog.cancel();
                            }
                        });
                        alert.show();
                    }
                }
            });

            return convertView;
        }

        @Override
        public boolean hasStableIds() {
            return true;
        }

        @Override
        public boolean isChildSelectable(int groupPosition, int childPosition) {
            return true;
        }
    }
}

我很感激这方面的任何指导。感谢

Answer 1

是。这很简单。您所要做的就是获取对按钮的引用并将可见性设置为已消失。像这样：

Button sampleButton = (Button) findViewById(R.id.sample_button);
sampleButton.setVisiblity(View.GONE);

注意：当您将其设置为View.GONE时，也会删除最初为其提供的布局空间。如果您只想删除按钮并保持使用布局空间改为View.INVISIBLE。

编辑：以下是我如何让按钮重新出现：首先，我会使用布尔来跟踪活动处于活动状态时按钮的状态。然后在你的getChildView覆盖中，我会检查这个布尔值并相应地设置可见性。也许在getChildView回调中插入这样的内容，以便在单击列表项时不再出现按钮：

if (!showButton) {
Button button = (Button) findViewById(R.id.sample_button);
button.setVisibility(View.GONE);
}

至于回到屏幕。为了跟踪是否不显示按钮，我将使用布尔值并将其存储在SharedPreferences中。然后，同样在getChildView回调中，检查布尔值的状态并相应地进行设置。像这样：

SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
boolean showButtonStatusPref = settings.getBoolean("showButton", true);

if(!showButtonStatusPref) {
Button button = (Button) findViewById(R.id.sample_button);
button.setVisibility(View.GONE);
}

您唯一需要做的就是管理每个按钮的状态。

编辑2：我完全忽略了相同的布局用于子视图（duh！brain cramp :)）。

您仍然可以使用共享首选项来跟踪已下载的样本（您可以使用Set for this）。您还需要创建一种为每个样本分配“标识符”的方法。从那里你需要做的就是每次调用getChildView()时执行检查，如果Set包含选定的样本标识符，则将按钮可见性设置为不存在。这应该在未下载样本时显示按钮，在下载样本时不显示按钮。在getChildView()：

中也许是这样的

Set<String> defaultSet = new SortedSet<String>();
defaultSet.add("Nothing downloaded");
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SortedSet<String> listOfDowloaded = settings.getStringSet("isDownloadedList", );

if (listOfDownLoaded.contains(sampleDownloadIdentifier)) {
Button button = (Button) findViewById(R.id.some_id);
button.setVisiblity(View.GONE);
}

隐藏ExpandableListView中的按钮

1 个答案: