Question

我正在尝试检索一个视图，但它一直返回null，我该如何找到它？

public class TripDailyItinerary extends Activity {
ViewGroup layout;
View v;

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.html_content);  
TextView content = (TextView) findViewById(R.id.htmlContent);
layout = (ViewGroup) findViewById(R.layout.trip_content);
v = (View) layout.findViewById(R.id.bg); //where the error is


JSONObject reservation;
int resNumber = ((MyApp) this.getApplication()).getResNum();
String dailyitinerary = "";

try {
reservation = ((MyApp) this.getApplication()).getJSON().getJSONObject("response").getJSONArray("reservations").getJSONObject(resNumber);
dailyitinerary = reservation.getString("dailyitinerary");
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
content.setText(Html.fromHtml(dailyitinerary));
}

}

我在v =（查看）等等时继续得到NullPointerException。

Answer 1

layout = (ViewGroup) findViewById(R.layout.trip_content);
v = (View) layout.findViewById(R.id.bg); //where the error is

用下面的

替换上面两行

LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view view = inflater.inflate(R.layout.R.layout.trip_content,null);
TextView name = (TextView) view.findViewById(R.id.bg);

TextView可以用你的控件替换ImageView和任何其他。

Answer 2

使用此：

ViewGroup parent = (ViewGroup)findViewById(R.id.trip_layout);
LayoutInflater inflater =  (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View myView = inflater.inflate(R.layout.trip_content,parent);

如果要添加TextView

TextView content = (TextView)myView.findViewById(R.id.htmlContent);

因为null发出警告..

R.id.trip_layout是XML Layout的父布局。

如何在tabhost内的活动中查找tabhost内的视图？

2 个答案: