Question

其他阅读文件的方法。??
为什么不读..？
读取中的文本始终为“ java.lang.nullpointerexception ”。

public class TopRatedFragment extends Fragment {
private static final String FILENAME = "data.data";
private Context context;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.setting, container, false);
    EditText message = (EditText) rootView.findViewById(R.id.mesaage);
    read(rootView);
    return rootView;
}
   public void read(View view){
       EditText message = (EditText) view.findViewById(R.id.mesaage);
          try{
             FileInputStream fin = context.openFileInput(FILENAME);
             int c;
             String temp="";
             while( (c = fin.read()) != -1){
                 temp = temp + Character.toString((char)c);
              }
                  //Read Text
             message.setText(temp, BufferType.EDITABLE);
          }catch(Exception e){
                  //read Eroor
              message.setText(e.toString(), BufferType.EDITABLE);
          }
    }


}

谁可以帮助我。??

Answer 1

试试这个..

使用EditText message作为全局不要使用EditText message = (EditText) view.findViewById(R.id.mesaage);，如下所示

EditText message;

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

    View rootView = inflater.inflate(R.layout.setting, container, false);
    message = (EditText) rootView.findViewById(R.id.mesaage);
    read(rootView);
    return rootView;
}
   public void read(View view){
          try{
             FileInputStream fin = context.openFileInput(FILENAME);
             int c;
             String temp="";
             while( (c = fin.read()) != -1){
                 temp = temp + Character.toString((char)c);
              }
                  //Read Text
             message.setText(temp, BufferType.EDITABLE);
          }catch(Exception e){
                  //read Eroor
              message.setText(e.toString(), BufferType.EDITABLE);
          }
    }

Answer 2

尝试使用

FileInputStream fin = new FileInputStream(new File(FILENAME));

Answer 3

只是一个简单的解决方案.. 做一些事情：

//First get your current context then use it...
context = getActivity();
FileInputStream fin = context.openFileInput(FILENAME);

Android java.lang.nullpointerexception读取文件

3 个答案: