Question

我目前有一组标签，每个标签都绑定到一个片段，我终于在其中一个标签上找到了UI，看看它应该如何。这是一个截图，显示应用程序在正确加载后的外观（初始启动并滚动到选项卡后）： enter image description here 现在，在我点击后退按钮后（我没有，也不会打扰每个标签的backStack - 我不喜欢那个UI范例）然后使用应用程序切换器或从启动器重新启动，我的问题已经消失（他们没有重新加载）。我是否需要在onPause中实现某些内容以保存我的显示？为什么onResume不会照顾它？

package com.davekelley.polling;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.view.ViewGroup.LayoutParams;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.RelativeLayout;
import android.widget.ScrollView;
import android.widget.TableLayout;
import android.widget.TableRow;
import android.widget.TextView;
import android.support.v4.app.Fragment;

public class EconFragment extends Fragment {

    private ViewGroup container;
    private TableLayout questionContainer;
    private ScrollView scrollView;
    private ViewGroup econFragment;
    static int pos = 0;

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        Log.d("Econ", "onCreateView");
        this.container = container;
        return inflater.inflate(R.layout.econfragment, container, false);
    }

    public void onResume() {
        super.onResume();
        questionContainer = (TableLayout) getActivity().findViewById(R.id.questionContainer);

        LayoutInflater inflater = (LayoutInflater) getActivity().
        getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        //these lines are my first attempt to try and get the questions to repopulate after returning
        //from pressing back - as of yet, they don't repopulate the screen:
        //View econFragment = inflater.inflate(R.layout.econfragment, null);
        //container.addView(econFragment);

        int leftMargin=5;
        int topMargin=5;
        int rightMargin=5;
        int bottomMargin=5;
        while (pos < 10) {
        View question = inflater.inflate(R.layout.question, null);
        question.setId(pos);
        pos++;
        TableRow tr = (TableRow) question;
        TableLayout.LayoutParams trParams = new TableLayout.LayoutParams(
                TableLayout.LayoutParams.MATCH_PARENT,
                TableLayout.LayoutParams.WRAP_CONTENT);
        trParams.setMargins(leftMargin, topMargin, rightMargin, bottomMargin);
        tr.setLayoutParams(trParams);
        questionContainer.addView(tr);
        }
        Log.d("Econ", "onResume");
    }

    public void onAttach(Activity activity) {
        super.onAttach(activity);
        Log.d("Econ", "onAttach");
    }

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.d("Econ", "onCreate");

    }

    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        Log.d("Econ", "onActivityCreated");
    }

    public void onStart() {
        super.onStart();
        Log.d("Econ", "OnStart");
    }

    public void onPause() {
        super.onPause();    
        Log.d("Econ", "onpause");
    }

    public void onStop() {
        super.onStop();
        Log.d("Econ", "onstop");
    }

    public void onDestroyView() {
        super.onDestroyView();
        Log.d("Econ", "ondestroyview");
    }

    public void onDestroy() {
        super.onDestroy();
        Log.d("Econ", "ondestroy");

    }

    public void onDetach() {
        super.onDetach();
        Log.d("Econ", "ondetach");
    }
}

Answer 1

每个Activity都有自己的生命周期，从 onCreate 到 onDestroy 。在这里查看图片和非常详细的文章：Activities Lifecycle

当用户按下 PowerButton 或 BackButton 时，您的活动会自动循环并自动消亡。当您打开电源或重新启动时，活动从开始（ onCreate ）开始。

您应该实现保存和加载功能，并在 onPaused 回调和加载状态 onResume 回调中保存状态。它将防止在重新启动之间失去活动状态。

Answer 2

当我在我的应用程序的其他区域工作时，问题有点被放在了后面。事实证明解决方案很简单：代码中列出的pos变量是静态的，因此while循环不能从0-10重新定义。这是答案：Even though onCreateView runs again, View does not properly reassemble after BACK press?

从BACK按下返回应用程序后未重新加载界面

2 个答案: