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嘗試打開Android XML視圖時在Eclipse中引發NullPointerException？

2011-01-14 36 views
5

這裏是例外：嘗試打開Android XML視圖時在Eclipse中引發NullPointerException？

java.lang.NullPointerException 
at android.widget.TextView.setTextColor(TextView.java:1787) 
at android.widget.TabHost$LabelIndicatorStrategy.createIndicatorView(TabHost.java:521) 
at android.widget.TabHost.addTab(TabHost.java:204) 
at com.android.layoutlib.bridge.Bridge.setupTabHost(Bridge.java:880) 
at com.android.layoutlib.bridge.Bridge.postInflateProcess(Bridge.java:807) 
at com.android.layoutlib.bridge.Bridge.postInflateProcess(Bridge.java:813) 
at com.android.layoutlib.bridge.Bridge.computeLayout(Bridge.java:401) 
at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.computeLayout(Unknown Source) 
at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.renderWithBridge(Unknown Source) 
at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.recomputeLayout(Unknown Source) 
at com.android.ide.eclipse.adt.internal.editors.layout.gle2.GraphicalEditorPart.activated(Unknown Source) 
at com.android.ide.eclipse.adt.internal.editors.layout.LayoutEditor.pageChange(Unknown Source) 
at org.eclipse.ui.part.MultiPageEditorPart$2.widgetSelected(MultiPageEditorPart.java:290) 
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:234) 
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84) 
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1258) 
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1282) 
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1267) 
at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1061) 
at org.eclipse.swt.custom.CTabFolder.setSelection(CTabFolder.java:2743) 
at org.eclipse.swt.custom.CTabFolder.onMouse(CTabFolder.java:1429) 
at org.eclipse.swt.custom.CTabFolder$1.handleEvent(CTabFolder.java:257) 
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84) 
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1258) 
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3540) 
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3161) 
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2640) 
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2604) 
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2438) 
at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:671) 
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332) 
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:664) 
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149) 
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:115) 
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196) 
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110) 
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79) 
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:369) 
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179) 
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) 
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
at java.lang.reflect.Method.invoke(Method.java:616) 
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:619) 
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:574) 
at org.eclipse.equinox.launcher.Main.run(Main.java:1407)

這裏是main.xml文件與相關聯：

<?xml version="1.0" encoding="utf-8"?> 
<TabHost 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:id="@android:id/tabhost"> 

    <LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:padding="5dp"> 
    <TabWidget 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:id="@android:id/tabs" /> 
    <FrameLayout 
     android:id="@android:id/tabcontent" 
     android:layout_width="fill_parent" 
     android:layout_height="fill_parent"> 

     <include layout="@layout/basic_tab" /> 
     <include layout="@layout/advanced_tab" /> 

    </FrameLayout> 
    </LinearLayout> 
</TabHost>

兩個包含文件單獨工作就好了。但是當在標籤佈局中時，會發生此錯誤。任何修復？
下面是代碼：

import android.app.TabActivity; 
import android.content.res.Resources; 
import android.os.Bundle; 
import android.widget.TabHost; 

import com.mohit.geo2do.R; 

public class TaskEdit extends TabActivity { 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.edit_task); 

     Resources res = getResources(); 
     TabHost host = getTabHost(); 

     host.addTab(host.newTabSpec("basic") 
      .setIndicator("Basic", res.getDrawable(android.R.drawable.ic_menu_edit)) 
      .setContent(R.layout.basic_tab)); 
     host.addTab(host.newTabSpec("advanced") 
      .setIndicator("Advanced", res.getDrawable(android.R.drawable.ic_menu_manage)) 
      .setContent(R.layout.advanced_tab)); 

     host.setCurrentTab(0); 
    } 
}

這裏是XML文件，advanced_tab：

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="vertical" 
    android:id="@+id/advanced_tab_layout"> 

    <TextView 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentTop="true" 
    android:text="Notify me:" 
    android:textColor="#FFFFFF" 
    android:textStyle="bold" 
    /> 

    <CheckBox 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignParentTop="true" 
     android:id="@+id/task_due" 
     android:text="when task is due" 
     android:textColor="#FFFFFF" 
     android:textStyle="bold" 
     android:paddingTop="5dip" 
    /> 

    <CheckBox 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignParentTop="true" 
     android:id="@+id/task_overdue" 
     android:text="when task is overdue" 
     android:textColor="#FFFFFF" 
     android:textStyle="bold" 
     android:paddingTop="5dip" 
    /> 

    <CheckBox 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignParentTop="true" 
     android:id="@+id/task_datetime" 
     android:text="at" 
     android:textColor="#FFFFFF" 
     android:textStyle="bold" 
     android:paddingTop="5dip" 
    /> 

    <TextView 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentTop="true" 
    android:text="Calendar:" 
    android:textColor="#FFFFFF" 
    android:textStyle="bold" 
    android:paddingTop="5dip" 
    /> 

    <CheckBox 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignParentTop="true" 
     android:id="@+id/task_calendar" 
     android:text="Create a calendar event" 
     android:textColor="#FFFFFF" 
     android:textStyle="bold" 
     android:paddingTop="5dip" 
    /> 

</LinearLayout>

而且basic_tab.xml：

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent" 
android:orientation="vertical" 
android:id="@+id/basic_tab_layout"> 
<TextView 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentTop="true" 
    android:text="Title:" 
    android:textColor="#FFFFFF" 
    android:textStyle="bold" 
    android:paddingTop="5dip" 
/> 

<EditText 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:id="@+id/title" 
    android:hint="Name of the task..." 
/> 

<TextView 
    android:layout_height="wrap_content" 
    android:layout_width="wrap_content" 
    android:text="Importance:" 
    android:textColor="#FFFFFF" 
    android:textStyle="bold" 
    android:paddingTop="10dip" 
/> 

<RadioGroup 
    android:layout_height="wrap_content" 
    android:layout_width="fill_parent" 
    android:orientation="horizontal" 
    android:id="@+id/importance_grp"> 

    <RadioButton 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="High" 
     android:paddingRight="25dip" 
    /> 
    <RadioButton 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="Medium" 
     android:checked="true" 
     android:paddingRight="25dip" 
    /> 
    <RadioButton 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:text="Low" 
    /> 

</RadioGroup> 

<TextView 
    android:layout_height="wrap_content" 
    android:layout_width="wrap_content" 
    android:text="Due Date:" 
    android:textColor="#FFFFFF" 
    android:textStyle="bold" 
    android:paddingTop="10dip" 
/> 

<Spinner 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:id="@+id/due_date" 
    android:prompt="@string/due_date_prompt" 
    android:entries="@array/due_date_entries" 
/> 

    <TextView 
     android:layout_height="wrap_content" 
     android:layout_width="wrap_content" 
     android:text="Notes:" 
     android:textColor="#FFFFFF" 
     android:textStyle="bold" 
     android:paddingTop="10dip" 
    /> 

    <EditText 
     android:layout_height="wrap_content" 
     android:layout_width="fill_parent" 
     android:id="@+id/notes" 
     android:hint="Notes..." 
     android:minLines="4" 
    /> 

</LinearLayout>

UPDATE：

顯然：

host.addTab(host.newTabSpec("advanced") 
     .setIndicator("Advanced", res.getDrawable(android.R.drawable.ic_menu_manage)) 
     .setContent(R.layout.advanced_tab));

不會將佈局xml文件作爲內容。它應該是：

host.addTab(host.newTabSpec("advanced") 
     .setIndicator("Advanced", res.getDrawable(android.R.drawable.ic_menu_manage)) 
     .setContent(R.id.advanced_tab_layout));

其中setContent需要一個ID。我仍然得到這個錯誤，但在模擬器上，這些選項卡實際上顯示，但沒有內容！

來源

2011-01-14 Mohit Deshpande

+1

請上傳驗證碼。我沒有在您的XML中看到任何TextView。也許你已經把它們放在'basic_tab'或'advanced_tab'文件中。發佈完整的東西的人！ – 2011-01-14 07:33:25

回答

1

那麼，我剛剛清理了項目並刪除了edit_task.xml文件並重新創建它。現在它工作正常。

來源

2011-01-15 03:54:57

5

您列出的異常是佈局編輯器本身的錯誤。在運行Android佈局代碼時，我們沒有正確初始化SDK版本，這意味着TabWidget中的某些版本條件代碼將會運行（因爲它實際上並未運行在它認爲的版本中），因此運行會失敗。我們在ADT 10（連同其他各種渲染/預覽問題爲標籤。）解決這個

（This是查找正確的版本傳遞給渲染器的變更）

來源

2011-01-28 16:45:02

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