Question

我为非常长的问题道歉但添加了额外的代码。

我有问题。我刚刚发布了一个应用程序，我在两部手机和模拟器上测试过。一切都很好。

但问题是我从使用该应用的人那里得到了一些例外。

我正在使用

intent.putExtra("continue", "newGame");

判断用户是开始新游戏还是继续上次保存的游戏。

由于我使用TabActivity的扩展名，我将意图发送到TabActivity

得到这个

String continueGame = getIntent().getExtras().getString("continue");

然后再添加额外的

intent.putExtra("continue", continueGame);

当我到达活动时，我尝试

        String continueGame;
        Bundle extras;
        if (bundle == null) {
            extras = getIntent().getExtras();
            if (extras == null) {
                continueGame = null;
            } else {
                continueGame = extras.getString("continue");
            }
        } else {
            continueGame = (String) bundle.getSerializable("continue");
        }
        assert continueGame != null;
        if (!continueGame.equals("continue")) {  <===This is line 75 in GamePlayerActivity
            playersGame = setNewGame();
            startPlayingGame();
        }

但在这里我得到了NullPointerException。这是stack_trace

java.lang.RuntimeException: Unable to start activity ComponentInfo{home.android.yahtzee/home.android.yahtzee.activities.GameActivity}: java.lang.RuntimeException: Unable to start activity ComponentInfo{home.android.yahtzee/home.android.yahtzee.activities.GamePlayerActivity}: java.lang.NullPointerException
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
    at android.app.ActivityThread.access$2300(ActivityThread.java:125)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:123)
    at android.app.ActivityThread.main(ActivityThread.java:4627)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:521)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:871)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:629)
    at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.RuntimeException: Unable to start activity ComponentInfo{home.android.yahtzee/home.android.yahtzee.activities.GamePlayerActivity}: java.lang.NullPointerException
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
    at android.app.ActivityThread.startActivityNow(ActivityThread.java:2503)
    at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
    at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
    at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:656)
    at android.widget.TabHost.setCurrentTab(TabHost.java:328)
    at android.widget.TabHost.addTab(TabHost.java:213)
    at home.android.yahtzee.activities.GameActivity.onCreate(GameActivity.java:36)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
    ... 11 more
Caused by: java.lang.NullPointerException
    at home.android.yahtzee.activities.GamePlayerActivity.onCreate(GamePlayerActivity.java:75)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
    ... 20 more
java.lang.RuntimeException: Unable to start activity ComponentInfo{home.android.yahtzee/home.android.yahtzee.activities.GamePlayerActivity}: java.lang.NullPointerException
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
    at android.app.ActivityThread.startActivityNow(ActivityThread.java:2503)
    at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
    at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
    at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:656)
    at android.widget.TabHost.setCurrentTab(TabHost.java:328)
    at android.widget.TabHost.addTab(TabHost.java:213)
    at home.android.yahtzee.activities.GameActivity.onCreate(GameActivity.java:36)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
    at android.app.ActivityThread.access$2300(ActivityThread.java:125)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:123)
    at android.app.ActivityThread.main(ActivityThread.java:4627)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:521)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:871)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:629)
    at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
    at home.android.yahtzee.activities.GamePlayerActivity.onCreate(GamePlayerActivity.java:75)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
    ... 20 more
java.lang.NullPointerException
    at home.android.yahtzee.activities.GamePlayerActivity.onCreate(GamePlayerActivity.java:75)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
    at android.app.ActivityThread.startActivityNow(ActivityThread.java:2503)
    at android.app.LocalActivityManager.moveToState(LocalActivityManager.java:127)
    at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:339)
    at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:656)
    at android.widget.TabHost.setCurrentTab(TabHost.java:328)
    at android.widget.TabHost.addTab(TabHost.java:213)
    at home.android.yahtzee.activities.GameActivity.onCreate(GameActivity.java:36)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
    at android.app.ActivityThread.access$2300(ActivityThread.java:125)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:123)
    at android.app.ActivityThread.main(ActivityThread.java:4627)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:521)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:871)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:629)
    at dalvik.system.NativeStart.main(Native Method)

希望你可以像往常一样帮助：）

修改

public class GameActivity extends TabActivity {
    @Override
    public void onCreate(Bundle bundle){
        super.onCreate(bundle);
        setContentView(R.layout.tab_handler);
        Resources res = getResources(); // Resource object to get Drawables
        TabHost tabHost = getTabHost();  // The activity TabHost
        TabHost.TabSpec spec;  // Resusable TabSpec for each tab
        Intent intent;  // Reusable Intent for each tab
        Gson gson = new Gson();
        Player player = gson.fromJson(getIntent().getExtras().getString("player"), Player.class);
        String continueGame = getIntent().getExtras().getString("continue");
        intent = new Intent().setClass(this, GamePlayerActivity.class);
        intent.putExtra("player", gson.toJson(player));
        intent.putExtra("continue", continueGame);
        // Initialize a TabSpec for each tab and add it to the TabHost
        spec = tabHost.newTabSpec(player.getName()).setIndicator(player.getName(),
                res.getDrawable(player.getDroid()))
                .setContent(intent); <-----------Line 36
        tabHost.addTab(spec); 
    }
}

更新我从对话框

启动TabActivity

public class WhoIsPlayingDialog extends Dialog {
    private Player playerSelected;
    private DataApp app;

    public WhoIsPlayingDialog(final Context context) {
        super(context);
        setTitle(R.string.whoIsPlayingSpinnerTitle);
        setContentView(R.layout.who_is_playing_dialog);
        Spinner playerSpinner = (Spinner) findViewById(R.id.whoIsPlayingSpinner);
        app = (DataApp) context.getApplicationContext();
        PlayerAdapter playerAdapter = new PlayerAdapter(context, R.layout.player_view, app.db.getAllPlayers());
        playerAdapter.setDropDownViewResource(R.layout.player_view);
        playerSpinner.setAdapter(playerAdapter);
        playerSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
                playerSelected = (Player) adapterView.getItemAtPosition(view.getId());
                Button continueGameButton = (Button) findViewById(R.id.whoIsPlayingContinueGameButton);
                if (!app.db.getGame(playerSelected.getGameId()).isNewGame()) {
                    continueGameButton.setVisibility(View.VISIBLE);
                    continueGameButton.setOnClickListener(new View.OnClickListener() {
                        public void onClick(View view) {
                            Intent intent = new Intent(context, GameActivity.class);
                            Gson gson = new Gson();
                            intent.putExtra("player", gson.toJson(playerSelected));
                            intent.putExtra("continue", "continue");
                            context.startActivity(intent);
                            dismiss();
                        }
                    });
                }else {
                    continueGameButton.setVisibility(View.GONE);
                }
            }

            public void onNothingSelected(AdapterView<?> adapterView) {
            }
        });
        (findViewById(R.id.whoIsPlayingDialogOKButton)).setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                Intent intent = new Intent(context, GameActivity.class);
                Gson gson = new Gson();
                intent.putExtra("continue", "newGame");
                intent.putExtra("player", gson.toJson(playerSelected));
                context.startActivity(intent);
                dismiss();
            }
        }
        );
    }

}

注意到我在nullPointerException

中得到GameActivity aswell

at home.android.yahtzee.activities.GameActivity.onCreate(GameActivity.java:36)

Answer 1

根据堆栈跟踪，如果您的第75行是堆栈跟踪中的第75行，那么continueGame null。
您可能希望在运行时记录值的来源。

Bundle怎么样？您是否在onSaveInstanceState()？

中将数据写入捆绑包

android intent putExtras

1 个答案: