将Spinner/EditText中的值从一个活动传递到另一个活动

Question

当我直接从一个字符串向另一个活动传递值时，它可以工作。但是，如果我从EditText和Spinner中检索相同的值，然后单击一个按钮（启动新的活动），该应用程序将崩溃。

有了这个我的应用程序的工作原理：

String key; 
    String para; 
    Button btnViewProducts; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main_screen); 
     //StrictMode.enableDefaults(); 

     // Buttons 
     btnViewProducts = (Button) findViewById(R.id.btnViewProducts); 
     key = "kq"; 
     para = "Taxi_No"; 

     // View products click event 
     btnViewProducts.setOnClickListener(new View.OnClickListener() { 

      @Override 
      public void onClick(View view) { 
       // Launching All products Activity 
       Intent i = new Intent(getApplicationContext(), AllProductsActivity.class); 

       i.putExtra("keyval", key); 
       i.putExtra("paraval",para); 
       startActivity(i); 
      } 
     }); 

     // View products click event 
    } 
} 

但是，这并不工作：

这是我LogCat输出：

04-25 00:58:31.634: W/ResourceType(335): Skipping entry 0x7f040003 in package table 0 because it is not complex! 
04-25 00:58:31.644: W/dalvikvm(335): threadid=1: thread exiting with uncaught exception (group=0x40015560) 
04-25 00:58:31.695: E/AndroidRuntime(335): FATAL EXCEPTION: main 
04-25 00:58:31.695: E/AndroidRuntime(335): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.androidhive/com.example.androidhive.MainScreenActivity}: android.view.InflateException: Binary XML file line #10: Error inflating class android.widget.Spinner 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.app.ActivityThread.access$1500(ActivityThread.java:117) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.os.Handler.dispatchMessage(Handler.java:99) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.os.Looper.loop(Looper.java:123) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.app.ActivityThread.main(ActivityThread.java:3683) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at java.lang.reflect.Method.invokeNative(Native Method) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at java.lang.reflect.Method.invoke(Method.java:507) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at dalvik.system.NativeStart.main(Native Method) 
04-25 00:58:31.695: E/AndroidRuntime(335): Caused by: android.view.InflateException: Binary XML file line #10: Error inflating class android.widget.Spinner 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.view.LayoutInflater.createView(LayoutInflater.java:518) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:56) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:568) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.view.LayoutInflater.rInflate(LayoutInflater.java:623) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.view.LayoutInflater.inflate(LayoutInflater.java:408) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.view.LayoutInflater.inflate(LayoutInflater.java:320) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.view.LayoutInflater.inflate(LayoutInflater.java:276) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:207) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.app.Activity.setContentView(Activity.java:1657) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at com.example.androidhive.MainScreenActivity.onCreate(MainScreenActivity.java:30) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 
04-25 00:58:31.695: E/AndroidRuntime(335):  ... 11 more 
04-25 00:58:31.695: E/AndroidRuntime(335): Caused by: java.lang.reflect.InvocationTargetException 
04-25 00:58:31.695: E/AndroidRuntime(335):  at java.lang.reflect.Constructor.constructNative(Native Method) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at java.lang.reflect.Constructor.newInstance(Constructor.java:415) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.view.LayoutInflater.createView(LayoutInflater.java:505) 
04-25 00:58:31.695: E/AndroidRuntime(335):  ... 22 more 
04-25 00:58:31.695: E/AndroidRuntime(335): Caused by: java.lang.NullPointerException 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.content.res.AssetManager.getResourceTextArray(AssetManager.java:214) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.content.res.Resources.getTextArray(Resources.java:361) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.content.res.TypedArray.getTextArray(TypedArray.java:628) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.widget.AbsSpinner.<init>(AbsSpinner.java:73) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.widget.Spinner.<init>(Spinner.java:56) 
04-25 00:58:31.695: E/AndroidRuntime(335):  at android.widget.Spinner.<init>(Spinner.java:52) 
04-25 00:58:31.695: E/AndroidRuntime(335):  ... 25 more 

我一定要得到这些参数从文本字段和微调器中选择值。代码需要做什么修改？

Answer 1

读logcat中，这条线在这里告诉我们关于这个问题

Caused by: java.lang.NullPointerException 
    04-25 00:58:31.695: E/AndroidRuntime(335): at 
    android.content.res.AssetManager.getResourceTextArray(AssetManager.java:214) 

告诉我们，正在使用您的Spinner的Array是null。请检查您是否在Spinner

使用正确的名称为您Array还要注意，它似乎是一般最好使用Activity Context而不是Application Context除非这真的是你所需要的。您Intent可能是

Intent i = new Intent(ActivityName.this, AllProductsActivity.class); 

这显然不是在这里你的问题，但它的东西要记住

logcat的

logcat的可以在第一棘手，但寻找这行Caused by:NullpointerException, IllegalArgument, etc...然后，第一行代码，其中引用您的项目通常是一个好地方开始