Question

我正在创建一些带按钮的EditTexts，我创建了一个实现OnClickListener的类，我想在屏幕旋转后保存那些EditTexts，但它们总是消失。我知道

轮换活动被销毁并再次创建
我无法在Bundle中保存EditText，因为它没有实现Parcelable或类似的东西

所以我尝试用onSaveInstanceState(Bundle savedInstanceState)至少保存他们身上的ID和文字但它没有被调用，因为它不在主类中，而是在另一个名为ViewControl的调用中。我需要保存一些私有变量（text和id），这就是为什么我在我的类中有这个方法的原因。我试图从另一个onSaveInstance中调用这个方法，这个方法主要但是没有运气。你能告诉我一些简单的方法来编程创建一个在另一个下面的EditTexts并在屏幕旋转后保持它们吗？我真的找不到任何简单的方法......

主要课程

public class MainActivity extends Activity {

private ViewControl vc;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    vc = new ViewControl(this);


}


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

}

ViewControl类

import java.util.ArrayList;



public class ViewControl extends Activity implements View.OnClickListener{

    private Button btn;
    private RelativeLayout rl;
    private Activity act;
    private ArrayList<Integer> id;
    private ArrayList<String> userpath;
    private int lastId;

    public ViewControl(Activity activity) {

        this.act = activity;

        this.id = new ArrayList<Integer>();
        this.userpath = new ArrayList<String>();

        this.rl = (RelativeLayout)act.findViewById(R.id.layout);
        this.btn = (Button)act.findViewById(R.id.btn);

        this.id.add(Integer.valueOf(R.id.btn));
        this.btn.setOnClickListener(this);

    }


    @Override
    public void onClick(View v) {

        if(id.size() != 1)
            lastId = id.get(id.size() - 1);
        else
            lastId = R.id.btn;

        RelativeLayout.LayoutParams par = new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
        par.addRule(RelativeLayout.BELOW, lastId);

        EditText et = new EditText(act);

        et.setId(++lastId);
        id.add(Integer.valueOf(lastId));
        et.setText(Integer.toString(lastId));

        rl.addView(et, par);
        lastId = et.getId();
    }

    @Override
    public void onSaveInstanceState(Bundle savedInstanceState) {
      super.onSaveInstanceState(savedInstanceState);
      savedInstanceState.putIntegerArrayList("ids", id);
      savedInstanceState.putStringArrayList("userpaths", userpath);
      savedInstanceState.putInt("lastId", lastId);

      Toast.makeText(act, "Onsave", Toast.LENGTH_LONG).show();

    }

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

      this.id = savedInstanceState.getIntegerArrayList("ids");
      this.userpath = savedInstanceState.getStringArrayList("userpaths");
      this.lastId = savedInstanceState.getInt("lastId");

      Toast.makeText(act, "Onrestore", Toast.LENGTH_LONG).show();

      for(int i = 0; i < id.size(); i++)
      {
            RelativeLayout.LayoutParams par = new RelativeLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
            par.addRule(RelativeLayout.BELOW, lastId);
            EditText et = new EditText(act);
            et.setId(this.id.get(i));
      }

    }

}

Answer 1

调用的顺序错误（MainActivity和ViewControl）。首先，您应该添加数据，然后将Bundle传递给super进行保存（请参阅文档here）。（您的onRestoreInstanceState没问题）

Android - 从另一个类调用OnSaveInstanceState而不是main

1 个答案: