Question

我一直在关注如何在Android操作栏中实现搜索小部件的this tutorial。我的主要活动中的代码没有任何错误，但是当我在手机上运行代码时，应用程序崩溃了。有什么帮助吗？

这是logcat显示的内容

03-03 21:18:38.763  15310-15310/com.example.easylauncher E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.example.easylauncher, PID: 15310
    java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v7.widget.SearchView.setOnQueryTextListener(android.support.v7.widget.SearchView$OnQueryTextListener)' on a null object reference
            at com.example.easylauncher.HomeActivity.onCreateOptionsMenu(HomeActivity.java:72)
            at android.app.Activity.onCreatePanelMenu(Activity.java:2845)
            at android.support.v4.app.FragmentActivity.onCreatePanelMenu(FragmentActivity.java:275)
            at android.support.v7.app.ActionBarActivity.superOnCreatePanelMenu(ActionBarActivity.java:276)
            at android.support.v7.app.ActionBarActivityDelegate$1.onCreatePanelMenu(ActionBarActivityDelegate.java:79)
            at android.support.v7.app.ActionBarActivityDelegateBase.preparePanel(ActionBarActivityDelegateBase.java:979)
            at android.support.v7.app.ActionBarActivityDelegateBase.doInvalidatePanelMenu(ActionBarActivityDelegateBase.java:1182)
            at android.support.v7.app.ActionBarActivityDelegateBase.access$100(ActionBarActivityDelegateBase.java:79)
            at android.support.v7.app.ActionBarActivityDelegateBase$1.run(ActionBarActivityDelegateBase.java:118)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:155)
            at android.app.ActivityThread.main(ActivityThread.java:5696)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1028)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:823)
03-03 21:18:40.483  15310-15310/com.example.easylauncher D/Process﹕ killProcess, pid=15310
03-03 21:18:40.493  15310-15310/com.example.easylauncher D/Process﹕ com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException:138 java.lang.ThreadGroup.uncaughtException:693 java.lang.ThreadGroup.uncaughtException:690

这是我的主要活动类

public class HomeActivity extends ActionBarActivity implements SearchView.OnQueryTextListener {
    TextView mSearchText;
    ImageButton phoneButton;
    ImageButton contactsButton;
    ImageButton messagesButton;
    ImageButton cameraButton;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);

        setTitle("Apps");
        getActionBar();

        loadApps();
        loadListView();
        addClickListener();
        addphoneButtonListener();
        addmessagesButtonListener();
        addcontactsButtonListener();
        addcameraButtonListener();
        mSearchText = new TextView(this);
        mSearchText.setPadding(10, 10, 10, 10);
        mSearchText.setText("test");
        setContentView(mSearchText);





    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.actions, menu);
        SearchView searchView = (SearchView) menu.findItem(R.id.action_search).getActionView();
        searchView.setOnQueryTextListener(this);
        return true;
    }

    @Override
    public boolean onPrepareOptionsMenu(Menu menu) {
        return super.onPrepareOptionsMenu(menu);
    }

    @Override
    public boolean    onOptionsItemSelected       (MenuItem item) {
        Toast.makeText(this, "Selected Item: " + item.getTitle(), Toast.LENGTH_SHORT).show();
        return true;
    }

    // The following callbacks are called for the SearchView.OnQueryChangeListener
    public boolean onQueryTextChange(String newText) {
        newText = newText.isEmpty() ? "" : "Query so far: " + newText;
        mSearchText.setText(newText);
        mSearchText.setTextColor(Color.GREEN);
        return true;
    }

    public boolean      onQueryTextSubmit      (String query) {
        //Toast.makeText(this, "Searching for: " + query + "...", Toast.LENGTH_SHORT).show();
        mSearchText.setText("Searching for: " + query + "...");
        mSearchText.setTextColor(Color.RED);
        return true;
    }

这是我的actions.xml我收到所有showAsAction部分的错误，告诉我“应该使用app：showAsAction”

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:id="@+id/action_search"
        android:icon="@android:drawable/ic_menu_search"
        android:title="Action Bar Search"
        android:showAsAction="ifRoom"
        android:actionViewClass="android.widget.SearchView" />
    <item android:id="@+id/action_add"
        android:icon="@android:drawable/ic_menu_add"
        android:title="Action Bar Add" />
    <item android:id="@+id/action_edit"
        android:icon="@android:drawable/ic_menu_edit"
        android:showAsAction="always"
        android:title="Action Bar Edit" />
    <item android:id="@+id/action_share"
        android:icon="@android:drawable/ic_menu_share"
        android:title="Action Bar Share"
        android:showAsAction="ifRoom" />
</menu>

Answer 1

由于您正在使用支持包中的活动类（ActionBarActivity），因此您还需要使用支持小部件。

此外，要访问支持库中的showAsAction属性，您需要指定自定义命名空间。这是一个例子：

<menu xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto">
    ...
    <item android:id="@+id/action_search"
        android:icon="@android:drawable/ic_menu_search"
        android:title="Action Bar Search"
        app:actionViewClass="android.support.v7.widget.searchview"
        app:showAsAction="ifRoom"/>
    ...
</menu>

注意：不要忘记在您的活动中导入正确的类：

import android.support.v7.widget.SearchView;

Answer 2

我发现在调试模式下不会出现崩溃，但是如果在PROGUARD打开的情况下打开包装，那么崩溃就会发生！

我找到了这个帮助！

-keep class android.support.v7.widget.SearchView { *; }

无法将搜索小部件添加到操作栏

2 个答案: