我有自定义列表视图，其中包含内容和TTS选项，在使用TTS时抛出空指针异常，Listview也没有显示我的应用程序已停止。错误在Logcat中显示。
Applicationadapter.java
public class ApplicationAdapter extends ArrayAdapter<Application> implements
TextToSpeech.OnInitListener{
private List<Application> items;
private LayoutInflater inflator;
private MainActivity activity;
private ProgressDialog dialog;
public TextToSpeech tts;
public ImageButton btnaudioprayer;
public TextView text1;
ArrayAdapter<String> adapter;
public ApplicationAdapter(MainActivity context, List<Application> items){
super(context, R.layout.activity_row, items);
this.items = items;
inflator = LayoutInflater.from(getContext());
activity=context;
}
@Override
public int getCount(){
return items.size();
}
@Override
public View getView(int position, View convertView, ViewGroup parent){
ViewHolder holder = null;
tts = new TextToSpeech(activity, ApplicationAdapter.this);
//View v = convertView;
if ( convertView == null ){
convertView = inflator.inflate(R.layout.activity_row, null);
holder = new ViewHolder();
holder.text2 = (TextView) convertView.findViewById(R.id.text2);
holder.text1 = (TextView) convertView.findViewById(R.id.text1);
holder.count = (TextView) convertView.findViewById(R.id.count);
holder.pray = (Button) convertView.findViewById(R.id.pray);
holder.chk = (CheckBox) convertView.findViewById(R.id.checkbox);
holder.btnSpeak = (ImageButton) convertView.findViewById(R.id.btnaudioprayer);
convertView.setTag(holder);
}else {
holder = (ViewHolder) convertView.getTag();
}
holder.chk.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton view,
boolean isChecked) {
int getPosition = (Integer) view.getTag();
items.get(getPosition).setSelected(view.isChecked());
}
});
holder.pray.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
int getPosition= (Integer)v.getTag();
StringBuffer sb1 = new StringBuffer();
sb1.append("ID :");
sb1.append(Html.fromHtml(""+items.get(getPosition).getId()));
sb1.append("\n");
activity.praydata(items.get(getPosition).getId());
}
});
holder.btnSpeak.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View V) {
speakOut();
}
});
Application app = items.get(position);
holder.chk.setTag(position);
holder.pray.setTag(position);
holder.text2.setText(Html.fromHtml(app.getTitle()));
holder.text1.setText(Html.fromHtml(app.getContent()));
holder.count.setText(app.getCount()+"");
holder.chk.setChecked(app.isSelected());
return convertView;
}
static class ViewHolder {
public TextView text2;
public TextView text1;
public TextView count;
public CheckBox chk;
public Button pray;
public ImageButton btnSpeak;
private TextToSpeech tts;
}
@Override
public void onInit(int status) {
if (status == TextToSpeech.SUCCESS) {
int result = tts.setLanguage(Locale.US);
if (result == TextToSpeech.LANG_MISSING_DATA
|| result == TextToSpeech.LANG_NOT_SUPPORTED) {
Log.e("TTS", "This Language is not supported");
} else {
speakOut();
}
} else {
Log.e("TTS", "Initilization Failed!");
}
}
private void speakOut() {
String text = text1.getText().toString();
tts.speak(text, TextToSpeech.QUEUE_FLUSH, null);
}
这里我也提到了我的logcat错误。在我的logcat错误中，它显示了此行中的错误
String text = text1.getText().toString();。它正在抛出NullPointerException，它也在显示log.e文件。它没有运行speakout()方法。
07-18 12:17:11.456: E/TTS(2314): This Language is not supported
07-18 12:17:11.456: I/TextToSpeech(2314): Connected to ComponentInfo{com.svox.pico/com.svox.pico.PicoService}
07-18 12:17:11.586: D/AndroidRuntime(2314): Shutting down VM
07-18 12:17:11.586: W/dalvikvm(2314): threadid=1: thread exiting with uncaught exception (group=0x40a70930)
07-18 12:17:11.597: E/AndroidRuntime(2314): FATAL EXCEPTION: main
07-18 12:17:11.597: E/AndroidRuntime(2314): java.lang.NullPointerException
07-18 12:17:11.597: E/AndroidRuntime(2314): at com.example.jsonandroid.ApplicationAdapter.speakOut(ApplicationAdapter.java:182)
07-18 12:17:11.597: E/AndroidRuntime(2314): at com.example.jsonandroid.ApplicationAdapter.onInit(ApplicationAdapter.java:168)
07-18 12:17:11.597: E/AndroidRuntime(2314): at android.speech.tts.TextToSpeech.dispatchOnInit(TextToSpeech.java:640)
07-18 12:17:11.597: E/AndroidRuntime(2314): at android.speech.tts.TextToSpeech.access$1000(TextToSpeech.java:52)
07-18 12:17:11.597: E/AndroidRuntime(2314): at android.speech.tts.TextToSpeech$Connection.onServiceConnected(TextToSpeech.java:1297)
07-18 12:17:11.597: E/AndroidRuntime(2314): at android.app.LoadedApk$ServiceDispatcher.doConnected(LoadedApk.java:1101)
07-18 12:17:11.597: E/AndroidRuntime(2314): at android.app.LoadedApk$ServiceDispatcher$RunConnection.run(LoadedApk.java:1118)
07-18 12:17:11.597: E/AndroidRuntime(2314): at android.os.Handler.handleCallback(Handler.java:725)
07-18 12:17:11.597: E/AndroidRuntime(2314): at android.os.Handler.dispatchMessage(Handler.java:92)
07-18 12:17:11.597: E/AndroidRuntime(2314): at android.os.Looper.loop(Looper.java:137)
07-18 12:17:11.597: E/AndroidRuntime(2314): at android.app.ActivityThread.main(ActivityThread.java:5039)
07-18 12:17:11.597: E/AndroidRuntime(2314): at java.lang.reflect.Method.invokeNative(Native Method)
07-18 12:17:11.597: E/AndroidRuntime(2314): at java.lang.reflect.Method.invoke(Method.java:511)
07-18 12:17:11.597: E/AndroidRuntime(2314): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
在我的自定义列表视图中，我有文本和TTS按钮，点击按钮时，它必须播放内容的音频。
答案 0 :(得分：3)
您的变量text1未初始化，但已声明，因此正在执行text1.getText()，您实际上是从getText()尝试null。
也许您想要的是holder.text1（holder中的ViewHolder）？
答案 1 :(得分：2)
我会删除speakOut();中onInit(int status)的来电，我会像这样修改speakOut();函数：
private void speakOut(String text) {
tts.speak(text, TextToSpeech.QUEUE_FLUSH, null);
}
你的onclicklistener我会在这里改变：
@Override
public void onClick(View v) {
View parent = (View)v.getParent();
ViewHolder vh = (ViewHolder)parent.getTag();
TextView tv = vh.text1;
speakOut(tv.getText().toString());
}
那应该适合你。