java - 三星 CUP sdk 对话框示例的问题

Question

使用 Android Studio 构建一个 Samsung Gear Fit 对话框。我对这段代码有疑问。当我 mListView 使用 .setAdapter 时，它似乎失败了。当我在初始化时将 demo_list 传递到 mListView 时出现警告。所以这个 demo_list 可能有问题。我是 android 的新手，所以我不确定一些事情。我使用的代码库有几个布局文件。我将 ListView 放在 root_layout.xml 中，当我在 root_layout 中定义列表时，引用 demo_list 的错误消失了，但它在其他布局文件中也消失了。

所以问题是，即使我定义了 demo_list，应用程序在初始加载时崩溃，应用程序在使用 setAdapter 时崩溃。此外，当我放置一个断点并通过调试运行它时，findViewById 方法中存在循环逻辑。

Samsung Gear Fit (CUP SDK) http://forum.xda-developers.com/gear-fit/development/samsung-gear-fit-sdk-available-t2872803

我的仓库是 https://github.com/jackygrahamez/MayDay

我在 HomeActivity.java 中的代码块

    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_1, NAMES);

    ListView mListView = (ListView) findViewById(R.id.demo_list);

    mListView.setAdapter(adapter);

    mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            // S Pen SDK Demo programs
            if (position == MAYDAY_CUP) {
                if (mHelloCupDialog == null) {
                    mHelloCupDialog = new GearFitDialog(getApplicationContext());
                } else {
                    mHelloCupDialog.finish();
                    mHelloCupDialog = null;
                }
            }
        }
    });

逻辑猫

02-07 15:11:39.059  11358-11358/com.mayday.md I/SELinux﹕ Function: selinux_android_load_priority [0], There is no sepolicy file.
02-07 15:11:39.079  11358-11358/com.mayday.md I/SELinux﹕ Function: selinux_android_load_priority , spota verifySig and checkHash pass. priority version is VE=SEPF_SM-G900T_4.4.2_0034
02-07 15:11:39.079  11358-11358/com.mayday.md I/SELinux﹕ selinux_android_seapp_context_reload: seapp_contexts file is loaded from /data/security/spota/seapp_contexts
02-07 15:11:39.079  11358-11358/com.mayday.md E/dalvikvm﹕ >>>>> Normal User
02-07 15:11:39.079  11358-11358/com.mayday.md E/dalvikvm﹕ >>>>> com.mayday.md [ userId:0 | appId:10430 ]
02-07 15:11:39.079  11358-11358/com.mayday.md D/dalvikvm﹕ Late-enabling CheckJNI
02-07 15:11:39.319  11358-11358/com.mayday.md I/PersonaManager﹕ getPersonaService() name persona_policy
02-07 15:11:39.359  11358-11358/com.mayday.md I/PersonaManager﹕ getPersonaService() name persona_policy
02-07 15:11:39.399  11358-11358/com.mayday.md D/skia﹕ GFXPNG PNG bitmap created width:720 height:1280 bitmap id is 270
02-07 15:11:39.429  11358-11358/com.mayday.md I/dalvikvm-heap﹕ Grow heap (frag case) to 28.360MB for 8294416-byte allocation
02-07 15:11:39.449  11358-11358/com.mayday.md D/AndroidRuntime﹕ Shutting down VM
02-07 15:11:39.449  11358-11358/com.mayday.md W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x41742da0)
02-07 15:11:39.449  11358-11358/com.mayday.md E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.mayday.md, PID: 11358
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mayday.md/com.mayday.md.HomeActivity}: java.lang.NullPointerException
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2395)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2453)
            at android.app.ActivityThread.access$900(ActivityThread.java:173)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5579)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1268)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1084)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
            at com.mayday.md.HomeActivity.onCreate(HomeActivity.java:62)
            at android.app.Activity.performCreate(Activity.java:5451)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2359)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2453)
            at android.app.ActivityThread.access$900(ActivityThread.java:173)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5579)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1268)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1084)
            at dalvik.system.NativeStart.main(Native Method)
02-07 15:11:44.829  11358-11358/com.mayday.md I/Process﹕ Sending signal. PID: 11358 SIG: 9
02-07 15:12:29.939  12336-12336/com.mayday.md I/SELinux﹕ Function: selinux_android_load_priority [0], There is no sepolicy file.
02-07 15:12:29.949  12336-12336/com.mayday.md I/SELinux﹕ Function: selinux_android_load_priority , spota verifySig and checkHash pass. priority version is VE=SEPF_SM-G900T_4.4.2_0034
02-07 15:12:29.949  12336-12336/com.mayday.md I/SELinux﹕ selinux_android_seapp_context_reload: seapp_contexts file is loaded from /data/security/spota/seapp_contexts
02-07 15:12:29.959  12336-12336/com.mayday.md E/dalvikvm﹕ >>>>> Normal User
02-07 15:12:29.959  12336-12336/com.mayday.md E/dalvikvm﹕ >>>>> com.mayday.md [ userId:0 | appId:10431 ]
02-07 15:12:29.959  12336-12336/com.mayday.md D/dalvikvm﹕ Late-enabling CheckJNI
02-07 15:12:30.259  12336-12336/com.mayday.md I/PersonaManager﹕ getPersonaService() name persona_policy
02-07 15:12:30.309  12336-12336/com.mayday.md I/PersonaManager﹕ getPersonaService() name persona_policy
02-07 15:12:30.339  12336-12336/com.mayday.md D/skia﹕ GFXPNG PNG bitmap created width:720 height:1280 bitmap id is 270
02-07 15:12:30.349  12336-12336/com.mayday.md I/dalvikvm-heap﹕ Grow heap (frag case) to 28.354MB for 8294416-byte allocation
02-07 15:12:30.369  12336-12336/com.mayday.md D/AndroidRuntime﹕ Shutting down VM
02-07 15:12:30.369  12336-12336/com.mayday.md W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x41742da0)
02-07 15:12:30.379  12336-12336/com.mayday.md E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.mayday.md, PID: 12336
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mayday.md/com.mayday.md.HomeActivity}: java.lang.NullPointerException
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2395)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2453)
            at android.app.ActivityThread.access$900(ActivityThread.java:173)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5579)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1268)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1084)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
            at com.mayday.md.HomeActivity.onCreate(HomeActivity.java:62)
            at android.app.Activity.performCreate(Activity.java:5451)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2359)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2453)
            at android.app.ActivityThread.access$900(ActivityThread.java:173)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5579)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1268)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1084)
            at dalvik.system.NativeStart.main(Native Method)
02-07 15:12:33.289  12336-12336/com.mayday.md I/Process﹕ Sending signal. PID: 12336 SIG: 9

Answer 1

根据错误 logcat，通过你的 HomeActivity 'onCreate()'，我看到你的代码:

setContentView(R.layout.welcome_screen);

and:

ListView mListView = (ListView) findViewById(R.id.demo_list);

但是，您的布局“welcome_screen.xml”中没有 ListView“R.id.demo_list”，而是在您的布局“fragment_type_simple.xml”中定义了 ListView“R.id.demo_list”。

因此，如果布局“fragment_type_simple.xml”是您的 HomeActivity UI，那么您应该替换:

setContentView(R.layout.welcome_screen);
with:
setContentView(R.layout.fragment_type_simple);

否则，您应该在布局“welcome_screen.xml”中添加 ID 为“demo_list”的 ListView。

希望这是清楚的!