嗨我做了关于搜索查询的所有事情，并且在错误方面没有问题，但我一直得到nullpointerexception的运行时错误
下面的java src代码
package com.developer.bunamay.mplayer;
import android.app.Activity;
import android.app.SearchManager;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.PorterDuff.Mode;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.text.TextUtils;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.SeekBar;
import android.widget.TextView;
public class MainActivity extends Activity {
String LOG_CLASS = "MainActivity";
public static final PlayUtils PlayerController = PlayUtils.getInstance();
CustomAdapter customAdapter = null;
private MediaFileAdapter mediaFileAdapter = null;
public static final int PICK_FOLDER_REQUEST = 8;
static TextView playingSong;
Button btnPlayer;
static Button btnPause, btnPlay, btnNext, btnPrevious;
Button btnStop;
LinearLayout mediaLayout;
static LinearLayout linearLayoutPlayingSong;
ListView mediaListView;
SeekBar seekBar;
TextView textBufferDuration, textDuration;
static ImageView imageViewAlbumArt;
static Context context;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
context = MainActivity.this;
init();
}
private void init() {
getViews();
setListeners();
playingSong.setSelected(true);
seekBar.getProgressDrawable().setColorFilter(getResources().getColor(R.color.white), Mode.SRC_IN);
if (PlayerConstants.SONGS_LIST.size() <= 0) {
PlayerConstants.SONGS_LIST = PlayUtils.listOfSongs(getApplicationContext());
}
setListItems();
}
private void setListItems() {
customAdapter = new CustomAdapter(this, R.layout.custom_list, PlayerConstants.SONGS_LIST);
mediaListView.setAdapter(customAdapter);
mediaListView.setFastScrollEnabled(true);
}
private void getViews() {
playingSong = (TextView) findViewById(R.id.textNowPlaying);
btnPlayer = (Button) findViewById(R.id.btnMusicPlayer);
mediaListView = (ListView) findViewById(R.id.listViewMusic);
mediaLayout = (LinearLayout) findViewById(R.id.linearLayoutMusicList);
btnPause = (Button) findViewById(R.id.btnPause);
btnPlay = (Button) findViewById(R.id.btnPlay);
linearLayoutPlayingSong = (LinearLayout) findViewById(R.id.linearLayoutPlayingSong);
seekBar = (SeekBar) findViewById(R.id.seekBar);
btnStop = (Button) findViewById(R.id.btnStop);
textBufferDuration = (TextView) findViewById(R.id.textBufferDuration);
textDuration = (TextView) findViewById(R.id.textDuration);
imageViewAlbumArt = (ImageView) findViewById(R.id.imageViewAlbumArt);
btnNext = (Button) findViewById(R.id.btnNext);
btnPrevious = (Button) findViewById(R.id.btnPrevious);
}
private void setListeners() {
mediaListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View item, int position, long id) {
Log.d("TAG", "TAG Tapped INOUT(IN)");
PlayerConstants.SONG_PAUSED = false;
PlayerConstants.SONG_NUMBER = position;
boolean isServiceRunning = PlayUtils.isServiceRunning(MusicService.class.getName(), getApplicationContext());
if (!isServiceRunning) {
Intent i = new Intent(getApplicationContext(), MusicService.class);
startService(i);
} else {
PlayerConstants.SONG_CHANGE_HANDLER.sendMessage(PlayerConstants.SONG_CHANGE_HANDLER.obtainMessage());
}
updateUI();
changeButton();
Log.d("TAG", "TAG Tapped INOUT(OUT)");
}
});
btnPlayer.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(MainActivity.this, AudioPlayerActivity.class);
startActivity(i);
}
});
btnPlay.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Controls.playControl(getApplicationContext());
}
});
btnPause.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Controls.pauseControl(getApplicationContext());
}
});
btnNext.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Controls.nextControl(getApplicationContext());
}
});
btnPrevious.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Controls.previousControl(getApplicationContext());
}
});
btnStop.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(getApplicationContext(), MusicService.class);
stopService(i);
linearLayoutPlayingSong.setVisibility(View.GONE);
}
});
imageViewAlbumArt.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(MainActivity.this, AudioPlayerActivity.class);
startActivity(i);
}
});
}
@Override
protected void onResume() {
super.onResume();
try {
boolean isServiceRunning = PlayUtils.isServiceRunning(MusicService.class.getName(), getApplicationContext());
if (isServiceRunning) {
updateUI();
} else {
linearLayoutPlayingSong.setVisibility(View.GONE);
}
changeButton();
PlayerConstants.SEEKBAR_HANDLER = new Handler() {
@Override
public void handleMessage(Message msg) {
Integer i[] = (Integer[]) msg.obj;
textBufferDuration.setText(PlayUtils.getDuration(i[0]));
textDuration.setText(PlayUtils.getDuration(i[1]));
seekBar.setProgress(i[2]);
}
};
} catch (Exception e) {
}
}
@SuppressWarnings("deprecation")
public static void updateUI() {
try {
MediaItem data = PlayerConstants.SONGS_LIST.get(PlayerConstants.SONG_NUMBER);
playingSong.setText(data.getTitle() + " " + data.getArtist() + "-" + data.getAlbum());
Bitmap albumArt = PlayUtils.getAlbumart(context, data.getAlbumId());
if (albumArt != null) {
imageViewAlbumArt.setBackgroundDrawable(new BitmapDrawable(albumArt));
} else {
imageViewAlbumArt.setBackgroundDrawable(new BitmapDrawable(PlayUtils.getDefaultAlbumArt(context)));
}
linearLayoutPlayingSong.setVisibility(View.VISIBLE);
} catch (Exception e) {
}
}
public static void changeButton() {
if (PlayerConstants.SONG_PAUSED) {
btnPause.setVisibility(View.GONE);
btnPlay.setVisibility(View.VISIBLE);
} else {
btnPause.setVisibility(View.VISIBLE);
btnPlay.setVisibility(View.GONE);
}
}
public static void changeUI() {
updateUI();
changeButton();
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.action_about:
Intent about = new Intent(MainActivity.this, About.class);
startActivity(about);
break;
case R.id.action_exit:
finish();
break;
}
int id = item.getItemId();
// get music from specific folder
if (id == R.id.folder_music) {
Intent intent = new Intent(this, FolderPickerActivity.class);
startActivityForResult(intent, PICK_FOLDER_REQUEST);
return true;
}
// search songs by title
if (id == R.id.action_search_title) {
PlayerController.SEARCH_TYPE = "TITLE";
return true;
}
// search songs by artist
if (id == R.id.action_search_artist) {
PlayerController.SEARCH_TYPE = "ARTIST";
return true;
}
// search songs by album
if (id == R.id.action_search_album) {
PlayerController.SEARCH_TYPE = "ALBUM";
return true;
}
if (id == R.id.action_sort_title) {
MediaFileComparator.sortByTitle(PlayerController.SONGS_LIST);
MediaFileAdapter mediaAdapter = (MediaFileAdapter) mediaListView.getAdapter();
mediaAdapter.notifyDataSetChanged();
return true;
}
if (id == R.id.action_sort_album) {
MediaFileComparator.sortByAlbum(PlayerController.SONGS_LIST);
MediaFileAdapter mediaAdapter = (MediaFileAdapter) mediaListView.getAdapter();
mediaAdapter.notifyDataSetChanged();
return true;
}
if (id == R.id.action_sort_artist) {
MediaFileComparator.sortByArtist(PlayerController.SONGS_LIST);
MediaFileAdapter mediaAdapter = (MediaFileAdapter) mediaListView.getAdapter();
mediaAdapter.notifyDataSetChanged();
return true;
}
if (id == R.id.action_sort_duration) {
MediaFileComparator.sortByDuration(PlayerController.SONGS_LIST);
MediaFileAdapter mediaAdapter = (MediaFileAdapter) mediaListView.getAdapter();
mediaAdapter.notifyDataSetChanged();
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);
// init menu items for search
MenuItem itemSearchTitle = menu.findItem(R.id.action_search_title);
MenuItem itemSearchAlbum = menu.findItem(R.id.action_search_album);
MenuItem itemSearchArtist = menu.findItem(R.id.action_search_artist);
SearchView searchViewTitle = (SearchView) itemSearchTitle.getActionView();
SearchView searchViewAlbum = (SearchView) itemSearchAlbum.getActionView();
SearchView searchViewArtist = (SearchView) itemSearchArtist.getActionView();
searchViewTitle.setFocusable(true);
searchViewAlbum.setFocusable(true);
searchViewArtist.setFocusable(true);
// init searchable info for each menu item
searchViewTitle.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
searchViewTitle.setQueryHint("title...");
searchViewTitle.setIconified(true);
searchViewAlbum.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
searchViewAlbum.setQueryHint("album...");
searchViewAlbum.setIconified(true);
searchViewArtist.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
searchViewArtist.setQueryHint("artist...");
searchViewArtist.setIconified(true);
// set textChangeListeners for each type of search
final SearchView.OnQueryTextListener textChangeListenerTitle = new SearchView.OnQueryTextListener() {
@Override
public boolean onQueryTextChange(String newText) {
if (!TextUtils.isEmpty(newText)) {
mediaFileAdapter.getFilter().filter(newText);
}
return true;
}
@Override
public boolean onQueryTextSubmit(String query) {
return true;
}
};
SearchView.OnQueryTextListener textChangeListenerAlbum = new SearchView.OnQueryTextListener() {
@Override
public boolean onQueryTextChange(String newText) {
if (!TextUtils.isEmpty(newText)) {
mediaFileAdapter.getFilter().filter(newText);
}
return true;
}
@Override
public boolean onQueryTextSubmit(String query) {
return true;
}
};
SearchView.OnQueryTextListener textChangeListenerArtist = new SearchView.OnQueryTextListener() {
@Override
public boolean onQueryTextChange(String newText) {
if (!TextUtils.isEmpty(newText)) {
mediaFileAdapter.getFilter().filter(newText);
}
return true;
}
@Override
public boolean onQueryTextSubmit(String query) {
return true;
}
};
// apply listeners to searchViews
searchViewTitle.setOnQueryTextListener(textChangeListenerTitle);
searchViewAlbum.setOnQueryTextListener(textChangeListenerAlbum);
searchViewArtist.setOnQueryTextListener(textChangeListenerArtist);
return super.onCreateOptionsMenu(menu);
}
}
我一直在
上收到错误 searchViewTitle.setFocusable(true);
这里是显示错误的logcat
07-31 18:12:18.047 2066-2066/? E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.developer.bunamay.mplayer, PID: 2066
java.lang.NullPointerException
at com.developer.bunamay.mplayer.MainActivity.onCreateOptionsMenu(MainActivity.java:300)
at android.app.Activity.onCreatePanelMenu(Activity.java:2538)
at com.android.internal.policy.impl.PhoneWindow.preparePanel(PhoneWindow.java:436)
at com.android.internal.policy.impl.PhoneWindow.doInvalidatePanelMenu(PhoneWindow.java:800)
at com.android.internal.policy.impl.PhoneWindow$1.run(PhoneWindow.java:221)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
at android.view.Choreographer.doCallbacks(Choreographer.java:574)
at android.view.Choreographer.doFrame(Choreographer.java:543)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5001)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
07-31 18:12:18.051 587-599/? W/ActivityManager: Force finishing activity com.developer.bunamay.mplayer/.MainActivity
谢谢！
答案 0 :(得分：0)
itemSearchTitle的ActionView此时为空。