Android 如何自动更改下一个列表项的焦点
我正在编写一个音频播放器应用程序,在这个应用程序中,当一首新歌开始播放时,我必须自动将焦点切换到下一个列表项上,我可以播放下一首歌,但无法突出显示该歌曲Android 如何自动更改下一个列表项的焦点,android,android-listview,Android,Android Listview,我正在编写一个音频播放器应用程序,在这个应用程序中,当一首新歌开始播放时,我必须自动将焦点切换到下一个列表项上,我可以播放下一首歌,但无法突出显示该歌曲 <ListView android:id="@+id/list_slidermenu" android:layout_height="0dp" android:layout_width="match_parent" android:layout_weight=
<ListView
android:id="@+id/list_slidermenu"
android:layout_height="0dp"
android:layout_width="match_parent"
android:layout_weight="8"
android:layout_gravity="start"
android:scrollbars="none"
android:fastScrollEnabled="true"
android:choiceMode="singleChoice"
android:listSelector="@drawable/list_selector"
/>
单击ListView侦听器:
listview.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View view, int position,
long id) {
// TODO Auto-generated method stub
positionGlobal = position;
strNURL = audiosArrayList.get(positionGlobal).getUrl().toString();
strNTITLE = audiosArrayList.get(positionGlobal).getTitle().toString();
if(mediaPlayer!=null && mediaPlayer.isPlaying())
try {
mediaPlayer.stop();
} catch (Exception e) {
}
play();
textTrack.setText(strNTITLE);
}
});
}
listview.setOnItemClickListener(新的OnItemClickListener(){
@凌驾
public void onItemClick(适配器视图arg0、视图视图、内部位置、,
长id){
//TODO自动生成的方法存根
位置全局=位置;
strNURL=audiosArrayList.get(positionGlobal.getUrl().toString();
strnttitle=audiosArrayList.get(positionGlobal.getTitle().toString();
if(mediaPlayer!=null&&mediaPlayer.isPlaying())
试一试{
mediaPlayer.stop();
}捕获(例外e){
}
play();
textTrack.setText(strNTITLE);
}
});
}
用于自动切换到下一首歌曲的方法
public void next() {
if (positionGlobal == (audiosArrayList.size()-1)) {
positionGlobal = 0;
strNURL = audiosArrayList.get(positionGlobal).getUrl().toString();
strNTITLE = audiosArrayList.get(positionGlobal).getTitle().toString();
current_position = 0;
mediaPlayer.seekTo(current_position);
if(mediaPlayer!=null && mediaPlayer.isPlaying())
try {
mediaPlayer.stop();
} catch (Exception e) {
}
play();
textTrack.setText(strNTITLE);
}
else if(positionGlobal < audiosArrayList.size()) {
positionGlobal = positionGlobal+1;
strNURL = audiosArrayList.get(positionGlobal).getUrl().toString();
strNTITLE = audiosArrayList.get(positionGlobal).getTitle().toString();
current_position = 0;
mediaPlayer.seekTo(current_position);
if(mediaPlayer!=null && mediaPlayer.isPlaying())
try {
mediaPlayer.stop();
} catch (Exception e) {
}
play();
textTrack.setText(strNTITLE);
}
}
public void next(){
如果(positionGlobal==(audiosArrayList.size()-1)){
位置全局=0;
strNURL=audiosArrayList.get(positionGlobal.getUrl().toString();
strnttitle=audiosArrayList.get(positionGlobal.getTitle().toString();
当前位置=0;
mediaPlayer.seekTo(当前位置);
if(mediaPlayer!=null&&mediaPlayer.isPlaying())
试一试{
mediaPlayer.stop();
}捕获(例外e){
}
play();
textTrack.setText(strNTITLE);
}
else if(positionGlobal
适配器类:
public class AudioAdapter extends BaseAdapter {
ArrayList<Audio> actorList;
LayoutInflater vi;
int Resource;
ViewHolder holder;
Context context;
public AudioAdapter(Context context, int resource, ArrayList<Audio> objects) {
this.context = context;
this.vi = (LayoutInflater) context
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
this.Resource = resource;
this.actorList = objects;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return actorList.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return actorList.get(position);
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
// convert view = design
View v = convertView;
if (v == null) {
holder = new ViewHolder();
v = vi.inflate(Resource, null);
holder.tvName = (TextView) v.findViewById(R.id.title);
v.setTag(holder);
} else {
holder = (ViewHolder) v.getTag();
}
holder.tvName.setText(actorList.get(position).getTitle());
return v;
}
static class ViewHolder {
public TextView tvName;
}
}
公共类AudioAdapter扩展了BaseAdapter{
ArrayList actorList;
拉平机vi;
智力资源;
视窗座;
语境;
公共音频适配器(上下文、int资源、ArrayList对象){
this.context=上下文;
this.vi=(LayoutInflater)上下文
.getSystemService(上下文布局\充气机\服务);
这个。资源=资源;
this.actorList=对象;
}
@凌驾
public int getCount(){
//TODO自动生成的方法存根
返回actorList.size();
}
@凌驾
公共对象getItem(int位置){
//TODO自动生成的方法存根
返回actorList.get(位置);
}
@凌驾
公共长getItemId(int位置){
//TODO自动生成的方法存根
返回位置;
}
@凌驾
公共视图getView(最终整数位置、视图转换视图、视图组父视图){
//转换视图=设计
视图v=转换视图;
如果(v==null){
holder=新的ViewHolder();
v=vi.充气(资源,空);
holder.tvName=(TextView)v.findViewById(R.id.title);
v、 setTag(支架);
}否则{
holder=(ViewHolder)v.getTag();
}
holder.tvName.setText(actorList.get(position.getTitle());
返回v;
}
静态类视窗夹{
公共文本视图tvName;
}
}
为此,您必须向适配器发送值,该值将通知适配器listview的哪个位置将被设置为值。只有这样,您才能做到这一点。同样,您必须设置适配器。您的代码似乎很好,只需在适配器中调用notifyDataSetChange
,通知它阵列中的数据已更改,需要重新加载:
如果您需要在以前的位置获取项目,只需执行以下操作:
if (position != 0) {
positionGlobal = position - 1;
strNURL = audiosArrayList.get(positionGlobal).getUrl().toString();
strNTITLE = audiosArrayList.get(positionGlobal).getTitle().toString();
}
您可以通过以下步骤列表来实现这一点:
mediaPlayer.setOnCompletionListener(new OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer mp) {
// First set next position in positionGlobal
//highlight ListItem
audioAdapter.setSelectedItem(position);
// Then perform Click
listview.performItemClick(listview, positionGlobal, listview.getItemIdAtPosition(positionGlobal));
// Scroll to selected position
listview.smoothScrollToPosition(positionGlobal);
}
});
适配器类将如下所示:
public AudioAdapter(Context context, int resource, ArrayList<Audio> objects) {
public void setSelectedItem(int selectedItem) {
this.selectedItem = selectedItem;
notifyDataSetChange();
}
@Override
public View getView(final int position, View convertView, ViewGroup parent){
// convert view = design
View v = convertView;
// Your code
// set selected Item
if(position == selectedItem) {
// you can define your own color of selected item here
v.setBackgroundColor(StringUtils.getColorFromResources(R.color.light_blue));
} else {
// you can define your own default selector here
v.setBackground(StringUtils.getDrawableFromResources(R.drawable.abs__list_selector_holo_light));
}
}
}
公共音频适配器(上下文、int资源、ArrayList对象){
公共无效设置selectedItem(int selectedItem){
this.selectedItem=selectedItem;
notifyDataSetChange();
}
@凌驾
公共视图getView(最终整数位置、视图转换视图、视图组父视图){
//转换视图=设计
视图v=转换视图;
//你的代码
//设置所选项目
如果(位置==选择编辑项){
//您可以在此处定义所选项目的颜色
v、 setBackgroundColor(StringUtils.getColorFromResources(R.color.light_blue));
}否则{
//您可以在此处定义自己的默认选择器
v、 设置背景(StringUtils.getDrawableFromResources(R.drawable.abs\uu列表\u选择器\u全息灯));
}
}
}
希望能有帮助ツ 尝试,聚焦列表视图。不调用nofifiydatachanges
listview.setItemChecked(position, true);
你也可以试试
listview.setSelection(position);
使用NotifyDataSetchManager api通知listviewchnages@diva我必须在哪里使用audioAdapter.notifyDataSetChanged()?你能指出你在哪里修改listview吗?如果下一首歌当时不可见怎么办?您需要向下滚动才能看到正在播放的歌曲,一旦您这样做,它就会失去焦点。@user3249477那么您会推荐我吗?我必须在哪里使用audioAdapter.notifyDataSetChanged()?更改audiosArrayList中的项目后