2012-09-07 107 views
0

每个人我都遇到将日历从日期传递到我的Create_Event.class的问题。最初textView显示“文本”,然后当我点击“选择日期”按钮时,日历页面将显示,日期应该被传递给最初显示“文本”的textView。我尝试使用intent.putExtra将日期从日历页面传递到Create_Events页面,但由于NullPointerException,我得到了强制关闭错误。任何人都可以帮我解决这个问题吗?非常感谢。从日历中选择日期后传递日期

作为参考,代码:

Calendar.java

@Override 
       public void onClick(View view) 
       { 
        String date_month_year = (String)view.getTag(); 
        selectedDayMonthYearButton.setText(new StringBuilder().append("Selected:").append(date_month_year)); 

        Intent k = new Intent(Calendar_Event.this, Create_Events.class); 
        k.putExtra("passdate", date_month_year); 
       startActivity(k); 

Create_Event.java

Intent intent = this.getIntent(); 
     if(intent == null) 
     { 
     String strdata = intent.getExtras().getString("passdate"); 
     TextView txtDate = (TextView) findViewById(R.id.textDate); 
     txtDate.setText(strdata); 
     } 
     else 
     { 

     } 

***本来如果(意向== NULL)是如果(意向!= null),我认为改变它会工作,但事实并非如此。 :P

更新了logcat的:

09-07 12:03:28.177: E/AndroidRuntime(1033): FATAL EXCEPTION: main 
09-07 12:03:28.177: E/AndroidRuntime(1033): java.lang.RuntimeException: Unable to start activity ComponentInfo{main.page/main.page.Create_Events}: java.lang.NullPointerException 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at android.app.ActivityThread.access$600(ActivityThread.java:123) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at android.os.Handler.dispatchMessage(Handler.java:99) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at android.os.Looper.loop(Looper.java:137) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at android.app.ActivityThread.main(ActivityThread.java:4424) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at java.lang.reflect.Method.invokeNative(Native Method) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at java.lang.reflect.Method.invoke(Method.java:511) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at dalvik.system.NativeStart.main(Native Method) 
09-07 12:03:28.177: E/AndroidRuntime(1033): Caused by: java.lang.NullPointerException 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at main.page.Create_Events.onCreate(Create_Events.java:261) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at android.app.Activity.performCreate(Activity.java:4465) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049) 
09-07 12:03:28.177: E/AndroidRuntime(1033):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920) 

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任何帮助将不胜感激!再次感谢。

更新时间:

Bundle bundle = getIntent().getExtras(); 
    if(bundle != null) 
    { 

     String date = bundle.getString("date"); 
     TextView txtDate = (TextView) findViewById(R.id.textDate); 
     txtDate.setText(date);   
    } 
+0

您会在哪里得到错误?你能发布logcat错误吗? –

+0

我想要打开Create_Events页面时出现错误。 nullPointerException错误将出现在上面的代码行onCreate上。 – CallMyName

+0

行数261行Create_Events.java:261? –

回答

0

使用捆绑在Create_Events活动获取日期。在传递数据之前,您首先需要检查它是否为空。

Bundle bundle = getIntent().getExtras(); 

if(bundle != null) 
{ 
    String date = bundle.getString("passdate"); 
} 

捆绑一般使用关于各种活动之间传递数据。它 取决于你想要通过什么类型的值,但捆绑可以 保存所有类型的值并传递给新的活动。