简要说明：这是一个演讲文字应用程序，如果他们说的单词也是数据库文件中的单词，那么它也会有一个单词的图像。
所以我试图使用imageResource来设置图像，但它失败了，因为它使用了一个ArrayList和一个String作为imageResoruce函数的第一部分。当我打开应用程序时，它被认为是导致错误消息，因为它崩溃了。
Main.java
public class Main extends Activity {
private static final int VR_Request = 100;
private final String pathname = ".png"; //path name of an image file stored in the drawable folder
TextView speechInput;
TextView matchOrNot;
String[] wordBank; //
ArrayList<String> wordBANK;
ImageButton speechBtn;
ImageView image;
Resources res = getResources();
int resID;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_reverse_pictionary);
speechInput = (TextView) findViewById(R.id.english_word);
matchOrNot = (TextView) findViewById(R.id.matchOrNot);
wordBank = getResources().getStringArray(R.array.Words);
speechBtn = (ImageButton) findViewById(R.id.mic_pic_button);
wordBANK = new ArrayList<String>(Arrays.asList(wordBank));
image = (ImageView) findViewById(R.id.imageOfword);
}
public void onMic(View view) {
promptSpeechInput();
}
public void promptSpeechInput() {
}
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
if(requestCode == VR_Request && resultCode == RESULT_OK) {
ArrayList<String> result = intent.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS);
if(wordBANK.contains(result.get(0).toLowerCase())){
speechInput.setText(result.get(0).toUpperCase());
matchOrNot.setText("MATCH");
resID = res.getIdentifier(result.get(0).toLowerCase()+pathname, "drawable", getPackageName());
image.setImageResource(resID);
}else {
speechInput.setText(result.get(0));
matchOrNot.setText("NO MATCH");
}
}
super.onActivityResult(requestCode, resultCode, intent);
}
}
运行时错误消息：
08-10 21:07:37.678 2344-2344/com.example.speechtotext E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.speechtotext, PID: 2344
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.speechtotext/com.example.speechtotext.Main}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2327)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference
at android.content.ContextWrapper.getResources(ContextWrapper.java:87)
at android.view.ContextThemeWrapper.getResources(ContextThemeWrapper.java:81)
at com.example.speechtotext.Main.<init>(Main.java:38)
at java.lang.Class.newInstance(Native Method)
at android.app.Instrumentation.newActivity(Instrumentation.java:1067)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2317)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
任何想法？提前谢谢！
答案 0 :(得分：1)
移动代码：
Resources res = getResources();
进入onCreate()方法。
在创建活动之前，您无法使用getResources()。