Java SetContentView设置回主活动时应用程序崩溃

当我在另一个布局上设置内容视图时，它工作得很好，但当我将内容视图设置回主布局时，它崩溃了

我的主课和上面的一切。一切都是第一次在公共场所发生（）

对此进行更改

Log.d("--***** MAP  ", "::Loading Map");
can = this;
setContentView(R.layout.activity_main);
initializeMapsFragment();

---

所以我需要删除：can=this；

E/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.robertas.parking.bestfreeparking, PID: 3501
              java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
                  at android.view.ViewGroup.addViewInner(ViewGroup.java:3936)
                  at android.view.ViewGroup.addView(ViewGroup.java:3786)
                  at android.view.ViewGroup.addView(ViewGroup.java:3758)
                  at android.view.LayoutInflater.rInflate(LayoutInflater.java:810)
                  at android.view.LayoutInflater.parseInclude(LayoutInflater.java:916)
                  at android.view.LayoutInflater.rInflate(LayoutInflater.java:802)
                  at android.view.LayoutInflater.parseInclude(LayoutInflater.java:916)
                  at android.view.LayoutInflater.rInflate(LayoutInflater.java:802)
                  at android.view.LayoutInflater.inflate(LayoutInflater.java:504)
                  at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
                  at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
                  at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:284)
                  at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:143)
                  at com.robertas.parking.bestfreeparking.MainActivity$4.onClick(MainActivity.java:245)
                  at android.view.View.performClick(View.java:4780)
                  at android.view.View$PerformClick.run(View.java:19866)
                  at android.os.Handler.handleCallback(Handler.java:739)
                  at android.os.Handler.dispatchMessage(Handler.java:95)
                  at android.os.Looper.loop(Looper.java:135)
                  at android.app.ActivityThread.main(ActivityThread.java:5254)
                  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:903)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

Log.d("--***** MAP  ", "::Loading Map");
can = this;
setContentView(R.layout.activity_main);
initializeMapsFragment();