2011-12-01 50 views
0

在运行下面的代码时,我从Eclipse获取NullPointerException,无法准确地确定它。这是通过Eclipse btw在Android之前的代码。我曾尝试将私人课程移至UpdateTimeTask,因为我认为这是问题所在。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) 

回答

0

也许time变量未被初始化用于任务。你最终在onCreate中初始化一个本地。

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

而是执行此操作,

time = (TextView) findViewById(R.id.time1); 
+0

谢谢,这工作就像一个魅力! – adamwhiles

0

这可能是:

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

更新:

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

首先尝试注释掉该行确认:

m_handler.postDelayed(m_updateTime, DELAY); 

然后取消注释。

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