The specified child already has a parent错误

10-05 23:39:48.187: E/AndroidRuntime(12854): Caused by: java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
10-05 23:39:48.187: E/AndroidRuntime(12854): at android.view.ViewGroup.addViewInner(ViewGroup.java:1976)
10-05 23:39:48.187: E/AndroidRuntime(12854): at android.view.ViewGroup.addView(ViewGroup.java:1871)
10-05 23:39:48.187: E/AndroidRuntime(12854): at android.view.ViewGroup.addView(ViewGroup.java:1828)
10-05 23:39:48.187: E/AndroidRuntime(12854): at android.view.ViewGroup.addView(ViewGroup.java:1808)
10-05 23:39:48.187: E/AndroidRuntime(12854): at com.solar.WaterLevelActivity.InitUnitTimeLowestWaterLevel(WaterLevelActivity.java:49)
10-05 23:39:48.187: E/AndroidRuntime(12854): at com.solar.WaterLevelActivity.InitView(WaterLevelActivity.java:30)
10-05 23:39:48.187: E/AndroidRuntime(12854): at com.solar.WaterLevelActivity.onCreate(WaterLevelActivity.java:25)
10-05 23:39:48.187: E/AndroidRuntime(12854): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
10-05 23:39:48.187: E/AndroidRuntime(12854): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
10-05 23:39:48.187: E/AndroidRuntime(12854): ... 11 more

补充说明：InitUnitTimeLowestWaterLevel()在OnCreate函数中被调用，用来初始化界面。实现的效果是动态添加界面。

下面是出错的代码：

View Code

1     private void InitUnitTimeLowestWaterLevel() {
2         LinearLayout listMachines = (LinearLayout) findViewById(R.id.water_level_page_water_level_setting);
3         LayoutInflater inflater = LayoutInflater.from(WaterLevelActivity.this);
4         View tlWaterLevelInfo = inflater.inflate(R.layout.unit_time_water_level_item, null);
5         listMachines.addView(tlWaterLevelInfo);
6         listMachines.addView(tlWaterLevelInfo);        //这个地方出错了。
7     }

错误的原因：通过LayoutInflater实例化的一个布局(View)。被重复添加了两次。而一个View只能有一个父控件。当第二次添加的时候，又要改变这个控件的父控件（虽然是同一个父控件，但是也要通过改变该View的父控件来实现）。运行时又不允许一个有父控件的子控件在有了一个父控件时，改变他的父控件。

解决方案：重新用布局文件实例化一个子控件，再添加到父控件上。