從導航抽屜的活動傳遞到具有相對布局的Android的錯誤

Question

在我的應用程序中，我使用Android的Navigation Drawer組件。 從此活動中，我開始另一個不使用導航抽屜的活動，但應用程序因以下錯誤而崩潰：

07-15 08:52:49.441: E/AndroidRuntime(1639): FATAL EXCEPTION: main
07-15 08:52:49.441: E/AndroidRuntime(1639): java.lang.NullPointerException
07-15 08:52:49.441: E/AndroidRuntime(1639):     at com.app.UserProfileActivity$detailUserAdapter.getView(UserProfileActivity.java:143)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.widget.AbsListView.obtainView(AbsListView.java:2143)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.widget.ListView.measureHeightOfChildren(ListView.java:1246)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.widget.ListView.onMeasure(ListView.java:1158)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.View.measure(View.java:15518)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.widget.RelativeLayout.measureChild(RelativeLayout.java:666)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:477)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.View.measure(View.java:15518)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:681)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:461)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.View.measure(View.java:15518)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4825)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.View.measure(View.java:15518)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4825)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1404)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.widget.LinearLayout.measureVertical(LinearLayout.java:695)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.View.measure(View.java:15518)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4825)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2176)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.View.measure(View.java:15518)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1874)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1089)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1265)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at 
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4351)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.Choreographer.doCallbacks(Choreographer.java:562)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.os.Handler.handleCallback(Handler.java:725)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.os.Handler.dispatchMessage(Handler.java:92)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.os.Looper.loop(Looper.java:137)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at android.app.ActivityThread.main(ActivityThread.java:5041)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at java.lang.reflect.Method.invokeNative(Native Method)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at java.lang.reflect.Method.invoke(Method.java:511)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
07-15 08:52:49.441: E/AndroidRuntime(1639):     at dalvik.system.NativeStart.main(Native Method)

我的第一個活動的xml布局是：

<android.support.v4.widget.DrawerLayout
    android:id="@+id/slideMenu_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_below="@id/relativeLayoutBanner" >

    <FrameLayout
        android:id="@+id/content_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@null" >

            <RelativeLayout
                 >

                <EditText
                     >

                    <requestFocus />
                </EditText>

                <ListView
                     >
                </ListView>

                <ImageView
                     />

                <TextView
                     />

                <TextView
                    />

                <ProgressBar
                    />
            </RelativeLayout>

            <TextView
                />
        </RelativeLayout>
    </FrameLayout>

    <ListView
        android:id="@+id/left_drawer"
        android:layout_width="240dp"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:background="#111"
        android:choiceMode="singleChoice"
        android:divider="@color/gray_auth"
        android:dividerHeight="2dp" />
</android.support.v4.widget.DrawerLayout>

我第二個活動的xml布局：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >



    <ListView
       >

    </ListView>

</RelativeLayout>

我從第一個活動（在列表視圖中）的onitemclicklistener調用第二個活動。 該問題不在其余代碼中，因為這很好。 它在第一個活動中由於導航抽屜的實現而崩潰。 錯誤（在UserProfileActivity的第143行中）是在第二個listView的適配器中。

適配器是：

private class detailUserAdapter extends ArrayAdapter<String> {

    private Context context;
    private ArrayList<String> campi;
    private ArrayList<String> dettagli;

    public detailUserAdapter(Context context, ArrayList<String> campi,
            ArrayList<String> dettagli) {
        super(context, R.layout.myprofile_user_item_layout, campi);
        this.context = context;
        this.campi = campi;
        this.dettagli = dettagli;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // First let's verify the convertView is not null
        if (convertView == null) {
            // This a new view we inflate the new layout
            LayoutInflater inflater = (LayoutInflater) context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = inflater.inflate(
                    R.layout.myprofile_user_item_layout, parent, false);
        }
        // Now we can fill the layout with the right values
        TextView userCampo = (TextView) convertView
                .findViewById(R.id.textViewUser);
        userCampo.setText(campi.get(position));


        TextView userDetail = (TextView) convertView
                .findViewById(R.id.textViewUserDetail);
        userDetail.setText(dettagli.get(position));


        return convertView;
    }

當存在userDetail.setText（dettagli.get（position））時，該行中的錯誤。 但是向量包含一個值，並且textview正確存在。 myprofile_user_item_layout的完整代碼為

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="15dp" >

<TextView
    android:id="@+id/textViewUser"
    android:layout_width="110dp"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:text="TextView" />

<TextView
    android:id="@+id/textViewUserDetail"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/textViewUser"
    android:layout_centerHorizontal="false"
    android:layout_toRightOf="@+id/textViewUser"
    android:text="TextView"
    android:textColor="@color/red" />

Answer 1

你應該改變

convertView = inflater.inflate(R.layout.myprofile_user_item_layout, parent, false);

至

convertView = inflater.inflate(R.layout.myprofile_user_item_layout,null);

由於您不依賴於父布局的參數，因此不應在您所使用的布局的放大中指定它。