android 解決.XML提示ava.lang.NullPointerException at錯誤後XML沒顯示，androidexception

android 解決.XML提示ava.lang.NullPointerException at錯誤後XML沒顯示，androidexception

提示錯誤：

 1 java.lang.NullPointerException 2 Exception details are logged in Window > Show View > Error Log 3  4 java.lang.NullPointerException 5     at com.xxxx.ui.xxxxview.IphoneTreeView.onLayout(IphoneTreeView.java:236) 6     at android.view.View.layout(View.java:14817) 7     at android.view.ViewGroup.layout(ViewGroup.java:4631) 8     at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453) 9     at android.widget.FrameLayout.onLayout(FrameLayout.java:388)10     at android.view.View.layout(View.java:14817)11     at android.view.ViewGroup.layout(ViewGroup.java:4631)12 ....

意思是提示 指標或對象空，具體列表；

解決方案：點擊“IphoneTreeView.java:236”會跳到錯誤的.JAVA代碼中，

對對象或指標進行判斷不為NULL再使用。如：

1         int state =0; 2         if (mAdapter != null)//加上判斷就可以解決，之前是沒有判斷引起的3           state = mAdapter.getTreeHeaderState(groupPos, childPos);