Question

TextView.setText在函数调用中不起作用。我在方法中传递数据（“changeText”）。代码不起作用。应用停止工作。当我尝试更改onActivityCreated中的文本时它可以工作，但是当我在函数中传递数据时它不起作用

public class Fragment_b extends Fragment {

TextView tv;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment_b, container, false);
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    tv = (TextView) getActivity().findViewById(R.id.textView);
    changeText(90);
}
public void changeText(int data)
{
    tv = (TextView) getActivity().findViewById(R.id.textView);
    tv.setText(String.valueOf(data));
}
}

Answer 1

首先将mainView声明为全局。然后使用那个来查找你的视图，调用getActivty（）。findViewById ...没有使用与你相同的布局。

private View rootView;

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

rootView = inflater.inflate(R.layout.fragment_b, container, false);
    return rootView;
}

然后

 tv = (TextView) rootView.findViewById(R.id.textView);

Answer 2

    public class Fragment_b extends Fragment {

       TextView tv;
       @Nullable
       @Override



        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle      savedInstanceState) {
               View v = inflater.inflate(R.layout.fragment_b, container, false);
tv = (TextView)v.findViewById(R.id.textView);
return v;
           }

       @Override
       public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        changeText(90,tv);
       }
       public void changeText(int data,TextView tv)
       {
        tv.setText(String.valueOf(data));
       }
    }

Answer 3

getActivity().runOnUiThread(new Runnable()
    {
        @Override
        public void run()
        {
            changeText(90);
        }
    });

TextView setText方法在Fragment中不起作用

3 个答案: