Android将正常布局更改为选项卡布局错误在图像按钮和其他？

Question

我按照这个创建了一个Android Radio Stream

它在那里工作正常所以我试图添加一个标签布局

所以我按照这个添加Tab布局

在那里我已经添加但是我有很多错误所以我改变了一些像

从

 protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.main_activity);

对此

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    View viewRoot = inflater.inflate(R.layout.main_activity, container, false);

并且viewRoot.findViewById在一些地方添加on-create但是在On之后创造了我曾经拥有的东西getActivity().findViewById

因为我已经return viewRoot;在onCreate中给出 了它是不可能的

现在我收到了错误 play.setBackground(getResources().getDrawable(R.drawable.volume0));

喜欢

    java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setBackground(android.graphics.drawable.Drawable)' on a null object reference
at star.yx.tabview.ProfileFragment.updatePlayStatus(ProfileFragment.java:370)
at star.yx.tabview.ProfileFragment.setIFace(ProfileFragment.java:205)
at star.yx.tabview.ProfileFragment.onCreateView(ProfileFragment.java:158)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:2184)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1298)
at android.support.v4.app.FragmentManagerImpl.moveFragmentsToInvisible(FragmentManager.java:2323)
at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2136)
at android.support.v4.app.FragmentManagerImpl.optimizeAndExecuteOps(FragmentManager.java:2092)
at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:1969)
at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:620)
at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:143)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1268)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1116)
at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1642)
at android.view.View.measure(View.java:18596)
at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:728)
at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:464)
at android.view.View.measure(View.java:18596)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5827)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139)
at android.view.View.measure(View.java:18596)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5827)
at android.support.v7.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:393)
at android.view.View.measure(View.java:18596)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5827)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at android.view.View.measure(View.java:18596)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5827)
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1435)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:721)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:612)
at android.view.View.measure(View.java:18596)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5827)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2897)
at android.view.View.measure(View.java:18596)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2248)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1306)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1548)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1191)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6642)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:777)
at android.view.Choreographer.doCallbacks(Choreographer.java:590)
at android.view.Choreographer.doFrame(Choreographer.java:560)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:763)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5951)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:

我在ProfileFragment中添加了我的代码用于测试目的....

任何人都可以建议我如何使用我的活动在像我的示例表格布局的片段请建议我这样

更新

我正在努力的一切.

我只是在平板电脑布局中使用我的无线电布局所以在一个标签中,我可以在其他播放收音机,我可以使用其他一些.但在这里我的无线电服务不在片段/标签布局所以我得到了很多错误任何人都可以建议我如何添加标签布局到我的电台活动我跟着我的安卓教程但我试过和累了请帮帮我怎么用这两个例子合二为一......

Answer 1

原因

您正在onResume调用setIFace()内部触发updatePlayStatus方法的方法。

如果你看一下updatePlayStatus方法，你会看到有一个 ImageView play 被分配给带有 ID 的视图icon_play

private void updatePlayStatus() {
    ImageView play = (ImageView) findViewById(R.id.icon_play);

    if ("stop".equals(etat_lecture) || "pause".equals(etat_lecture)) {
        play.setBackground(getDrawable(R.drawable.ic_equalizer0));
    } else {
        play.setBackground(getDrawable(R.drawable.ic_equalizer));
    }
}

如果 Android 找不到任何 ID = 的视图，icon_play那么 Android 会自动分配它null。稍后您调用 play.setBackground，由于play您的情况下变量为空，因此您将收到空指针异常。

解决方案

• 首先，检查您的片段类中是否使用了正确的布局，即。一定有一些带有 ID 的视图icon_play。
• 其次，尝试清理和构建项目。它可能是由于错误生成的 R.java 类而发生的
• 最重要的是，使用getActivityviewRoot.findViewById代替getActivity 可能会返回 null，或者最好使用ButterKnife来避免所有这些样板文件getActivity().findViewById

MainActivity 代码是完整的网格，我已将其分解为片段

你可以在我的GitHub上查看源代码

https://github.com/hiteshsahu/Android-Radio