android - Radio Group - 获取选定的 ID

Question

我正在尝试从单选按钮组获取单选按钮的文本，但失败了。

这是我得到的错误信息:

05-06 17:32:30.317  20460-20460/pt.smartgeo.aees E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: pt.smartgeo.aees, PID: 20460
    java.lang.NullPointerException
            at pt.smartgeo.aees.CreatePoint$1.onClick(CreatePoint.java:121)
            at android.view.View.performClick(View.java:4438)
            at android.view.View$PerformClick.run(View.java:18422)
            at android.os.Handler.handleCallback(Handler.java:733)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5017)
            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:779)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
            at dalvik.system.NativeStart.main(Native Method)

这是我的广播组:

    <RadioGroup
            android:id="@+id/potencia"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/nColuna"
            android:layout_toRightOf="@+id/Potencia">

            <RadioButton
android:id="@+id/rb2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="100W" />

            <RadioButton
android:id="@+id/rb3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="150W" />

            <RadioButton
android:id="@+id/rb1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="250W" />

            <RadioButton
android:id="@+id/rb4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="400W" />

        </RadioGroup>

这就是我试图让它成为我的广播组文本的地方:

RadioGroup group = (RadioGroup) view.findViewById(pt.smartgeo.aees.R.id.potencia);
int selectedId = group.getCheckedRadioButtonId();
RadioButton radioButton = (RadioButton) view.findViewById(selectedId);
Toast.makeText(getActivity().getApplicationContext(),
    "rebenta? " + radioButton.getText() , Toast.LENGTH_SHORT).show();

我已经看到我的 selectID 不为空，而且我选择的每个单选按钮都不同。但是我的 toast 有 java 空指针

我做的一些 logcat 和实际结果:

        Log.d("id do group", "Id do group: " + group.getId());
        Log.d("selected do group", "id do selected radio button " + group.getCheckedRadioButtonId());
        Log.d("selectedid", "selected id: " + selectedId);

结果:

05-07 10:26:15.374  13928-13928/pt.smartgeo.aees D/id do group﹕ Id do group: 2131296349
05-07 10:26:15.374  13928-13928/pt.smartgeo.aees D/selected do group﹕ id do selected radio button 2131296353
05-07 10:26:15.374  13928-13928/pt.smartgeo.aees D/selectedid﹕ selected id: 2131296353

Answer 1

单选按钮没有 android:id 属性，它们都没有使用 android:checked = "true" 。不确定你是否用代码检查过你的 radio 。