epoch中的nullpointerexception（android）

在運行下面的代碼時，我從Eclipse獲取NullPointerException，無法準確地確定它。這是通過Eclipse btw在Android之前的代碼。我曾嘗試將私人課程移至UpdateTimeTask，因爲我認爲這是問題所在。epoch中的nullpointerexception（android）

public class ClockWidgetXActivity extends Activity { 
private UpdateTimeTask m_updateTime; 
private Handler m_handler; 
private TextView time; 
private final int DELAY = 100; 
/** Called when the activity is first created. */ 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
    String currentDateTimeString = DateFormat.getTimeInstance().format(new Date()); 
    TextView time = (TextView) findViewById(R.id.time1); 
    Typeface font = Typeface.createFromAsset(getAssets(), "Carre.ttf"); 
    time.setTypeface(font); 
    time.setTextSize(65.f); 
    time.setText(currentDateTimeString); 
    m_updateTime = new UpdateTimeTask(); 

    m_handler = new Handler(); 
    m_handler.post(m_updateTime); 

} 

private class UpdateTimeTask implements Runnable { 
    public void run() { 
     String currentDateTimeString = DateFormat.getTimeInstance().format(new Date()); 
     time.setText(currentDateTimeString); 

     m_handler.postDelayed(m_updateTime, DELAY); 
    } 
} 
}

的logcat：

12-01 03:26:54.642: E/AndroidRuntime(673): FATAL EXCEPTION: main 
12-01 03:26:54.642: E/AndroidRuntime(673): java.lang.NullPointerException 
12-01 03:26:54.642: E/AndroidRuntime(673): at com.sokydevelopers.clockWidgetX.ClockWidgetXActivity$UpdateTimeTask.run(ClockWidgetXActivity.java:23) 
12-01 03:26:54.642: E/AndroidRuntime(673): at android.os.Handler.handleCallback(Handler.java:605) 
12-01 03:26:54.642: E/AndroidRuntime(673): at android.os.Handler.dispatchMessage(Handler.java:92) 
12-01 03:26:54.642: E/AndroidRuntime(673): at android.os.Looper.loop(Looper.java:137) 
12-01 03:26:54.642: E/AndroidRuntime(673): at android.app.ActivityThread.main(ActivityThread.java:4340) 
12-01 03:26:54.642: E/AndroidRuntime(673): at java.lang.reflect.Method.invokeNative(Native Method) 
12-01 03:26:54.642: E/AndroidRuntime(673): at java.lang.reflect.Method.invoke(Method.java:511) 
12-01 03:26:54.642: E/AndroidRuntime(673): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 
12-01 03:26:54.642: E/AndroidRuntime(673): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
12-01 03:26:54.642: E/AndroidRuntime(673): at dalvik.system.NativeStart.main(Native Method)

來源

2011-12-01 adamwhiles

也許time變量未被初始化用於任務。你最終在onCreate中初始化一個本地。

TextView time = (TextView) findViewById(R.id.time1); 
    Typeface font = Typeface.createFromAsset(getAssets(),

而是執行此操作，

time = (TextView) findViewById(R.id.time1);

來源

2011-12-01 04:00:40 Anirudh

謝謝，這工作就像一個魅力！ – adamwhiles

這可能是：

m_updateTime = new UpdateTimeTask(); 
m_handler = new Handler();

更新：

m_handler = new Handler(); 
m_updateTime = new UpdateTimeTask();

首先嚐試註釋掉該行確認：

m_handler.postDelayed(m_updateTime, DELAY);

然後取消註釋。

來源

2011-12-01 03:51:25

epoch中的nullpointerexception（android）

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