Question

应用程序假设在启动画面后显示主页面，但是，在X秒的启动超时后，应用程序崩溃了。请帮忙，我已附上错误和以下必要代码。

错误日志：

01-04 22:48:35.548: E/AndroidRuntime(28912): FATAL EXCEPTION: main
01-04 22:48:35.548: E/AndroidRuntime(28912): java.lang.RuntimeException: Unable to start activity   ComponentInfo{com.dapoaugury.channelappdemo/com.dapoaugury.channelappdemo.ChannelAppMainActivity}: java.lang.NullPointerException
01-04 22:48:35.548: E/AndroidRuntime(28912):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2295)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2349)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at android.app.ActivityThread.access$700(ActivityThread.java:159)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at android.os.Handler.dispatchMessage(Handler.java:99)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at android.os.Looper.loop(Looper.java:137)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at android.app.ActivityThread.main(ActivityThread.java:5419)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at java.lang.reflect.Method.invokeNative(Native Method)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at java.lang.reflect.Method.invoke(Method.java:525)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1187)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at dalvik.system.NativeStart.main(Native Method)
01-04 22:48:35.548: E/AndroidRuntime(28912): Caused by: java.lang.NullPointerException
01-04 22:48:35.548: E/AndroidRuntime(28912):    at com.dapoaugury.channelappdemo.ChannelAppMainActivity.initializeMenu(ChannelAppMainActivity.java:151)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at com.dapoaugury.channelappdemo.ChannelAppMainActivity.onCreate(ChannelAppMainActivity.java:118)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at android.app.Activity.performCreate(Activity.java:5372)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1104)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2257)

Splashscreen代码：

 new Handler().postDelayed(new Runnable() {

            @Override
            public void run() {
                mProgress.setProgress(SPLASH_TIME_OUT);
                Intent i = new Intent(ChannelAppSplashActivity.this, ChannelAppMainActivity .class);
                startActivity(i);
                finish();
            }
        }, SPLASH_TIME_OUT);

MainActivity Code（源自错误日志）：

public void initializeMenu() {
    ChannelAppMenuAdapter mAdapter = new ChannelAppMenuAdapter(this);

    // Profile
    mAdapter.addHeader("Account");

    // Parse FB Profile data
    // ChannelAppFBDataParser fbParser = new ChannelAppFBDataParser();
    // List<UserProfile> userProfile =
    // fbParser.parse(getApplicationContext());
    // title = userProfile.get(0).getUserName();
    // icon = R.drawable.ic_profile_pic;
    // ChannelAppMenuItemModel userItem = new ChannelAppMenuItemModel(title,
    // icon);
    // mAdapter.addItem(userItem);


    //Case 1:
    title = getIntent().getExtras().getString("name");
    icon = R.drawable.ic_profile_pic;
    ChannelAppMenuItemModel userItem = new ChannelAppMenuItemModel(title,
            icon);
    mAdapter.add(userItem);

    //Case 2:
    /*title = "Settings";
    icon = R.drawable.ic_settings;
    mAdapter.addItem(title, icon);*/

    //Case 2:
    if (isLogin){
        title = "Logout";
        }
    else{
    title = "Login";
    }
    icon = R.drawable.google_icon;
    mAdapter.addItem(title, icon);


    // Channels
    mAdapter.addHeader("Channels");

    //Case 4:
    title = "Exhibition";
    icon = R.drawable.icon;
    ChannelAppMenuItemModel exhibitItem = new ChannelAppMenuItemModel(
            title, icon);
    mAdapter.addItem(exhibitItem);

    //Case 5:
    title = "Galleries";
    icon = R.drawable.icon;
    ChannelAppMenuItemModel galleryItem = new ChannelAppMenuItemModel(
            title, icon);
    mAdapter.addItem(galleryItem);

    //Case 6:
    title = "Artists";
    icon = R.drawable.icon;
    ChannelAppMenuItemModel otherItem = new ChannelAppMenuItemModel(title,
            icon);
    mAdapter.addItem(otherItem);

    mAdapter.addHeader("Products");

    //Case 8:
    title = "Search";
    icon = R.drawable.ic_action_search;
    ChannelAppMenuItemModel searchItem = new ChannelAppMenuItemModel(title,
            icon);
    mAdapter.addItem(searchItem);


    mDrawerList = (ListView) findViewById(R.id.drawer);
    if (mDrawerList != null)
        mDrawerList.setAdapter(mAdapter);

    mDrawerList.setOnItemClickListener(new DrawerItemClickListener());

}

Answer 1

你没有给意图添加任何额外内容。所以这一行

title = getIntent().getExtras().getString("name");

崩溃。替换为

title = getIntent().getStringExtra("name");

或提供名为＆＃34; name＆＃34;

的意图

Answer 2

上面提到了可能的答案。我想分享一些关于如何阅读日志猫窗口的信息。

在Logcat窗口中，选择过滤器为＆＃34;错误＆＃34;
过滤后，在应用程序崩溃时，请查看日志。

01-04 22:48:35.548: E/AndroidRuntime(28912): Caused by: java.lang.NullPointerException
01-04 22:48:35.548: E/AndroidRuntime(28912):    at com.dapoaugury.channelappdemo.ChannelAppMainActivity.initializeMenu(ChannelAppMainActivity.java:151)
01-04 22:48:35.548: E/AndroidRuntime(28912):    at com.dapoaugury.channelappdemo.ChannelAppMainActivity.onCreate(ChannelAppMainActivity.java:118)

逐行检查直到你看到“＆＃34;

在该行下方，搜索您的应用程序包名称。
此处它将提供您可能遇到问题的行。一般来说，我建议你完全查看崩溃方法。
知道方法名称后，设置调试点并在调试模式下运行应用程序。您将轻松发现问题。

希望这有帮助。

Answer 3

您没有使用tiitle将putextra传递给来自初始屏幕的主要活动，因此它正在撤消null。

Intent i = new Intent(ChannelAppSplashActivity.this, ChannelAppMainActivity .class);
i.putExtra("name" , "tittlename");
startActivity(i);

Android应用无法启动活动componentInfo

3 个答案: