Question

我目前遇到问题，找不到太多帮助。

我的意图是编写用于调用两个类的onbackpressed方法。这里的问题是这是一个ListView，所以我在ListView中调用后退按钮，效果很好。

当用户按下引用日历名称的任何按钮时，将读取CSV文件，并显示格式。从那里，当用户单击“后退”按钮时，将显示一个或多个List_Event，这是完全合适的。

但是，从ListView本身开始，我需要回到我的HomePage，并且我对如何进行此操作一无所知。 Ť 在List_Event中添加onpressed的真正原因是有一个ItemArrayAdapter可以读取文件，因此在该逻辑中定义onpressedback按钮没有用。

这是班级：List_Event.java

package com.example.dell.display_event;

 import android.content.ClipData;
 import android.content.Intent;
 import android.graphics.Color;
import android.os.Bundle;
import android.os.Parcelable;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.View;
import android.widget.Button;
import android.widget.ListView;

import java.io.InputStream;
import java.util.List;


public class List_Event extends AppCompatActivity implements View.OnClickListener {

   // private List<Button> buttons;

    private ListView listView;
    private ItemArrayAdapter itemArrayAdapter;
    private static String file_name;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.list_event);

        Button january  = (Button) findViewById(R.id.January);
        january.setOnClickListener(this); // calling onClick() method

        Button february = (Button) findViewById(R.id.February);
        february.setOnClickListener(this); // calling onClick() method

        Button march = (Button) findViewById(R.id.March);
        march.setOnClickListener(this); // calling onClick() method

        Button april = (Button) findViewById(R.id.April);
        april.setOnClickListener(this);

        Button may=(Button) findViewById(R.id.May);
        may.setOnClickListener(this);

        Button june=(Button) findViewById(R.id.June);
        june.setOnClickListener(this);

        Button july=(Button) findViewById(R.id.July);
        july.setOnClickListener(this);

        Button august=(Button) findViewById(R.id.August);
        august.setOnClickListener(this);

        Button september=(Button) findViewById(R.id.September);
        september.setOnClickListener(this);

        Button october=(Button) findViewById(R.id.October);
        october.setOnClickListener(this);

        Button november=(Button) findViewById(R.id.November);
        november.setOnClickListener(this);

        Button december=(Button) findViewById(R.id.December);
        december.setOnClickListener(this);

        listView=(ListView) findViewById(R.id.listView);
        itemArrayAdapter = new ItemArrayAdapter(getApplicationContext(), R.layout.item_layout);


        Parcelable state = listView.onSaveInstanceState();
        listView.setAdapter(itemArrayAdapter);
        listView.onRestoreInstanceState(state);


    }



    @Override
    public void onClick(View v) {

        Button january  = (Button) findViewById(R.id.January);
        january.setOnClickListener(this); // calling onClick() method

        Button february = (Button) findViewById(R.id.February);
        february.setOnClickListener(this); // calling onClick() method

        Button march = (Button) findViewById(R.id.March);
        march.setOnClickListener(this); // calling onClick() method

        Button april = (Button) findViewById(R.id.April);
        april.setOnClickListener(this);

        Button may=(Button) findViewById(R.id.May);
        may.setOnClickListener(this);

        Button june=(Button) findViewById(R.id.June);
        june.setOnClickListener(this);

        Button july=(Button) findViewById(R.id.July);
        july.setOnClickListener(this);

        Button august=(Button) findViewById(R.id.August);
        august.setOnClickListener(this);

        Button september=(Button) findViewById(R.id.September);
        september.setOnClickListener(this);

        Button october=(Button) findViewById(R.id.October);
        october.setOnClickListener(this);

        Button november=(Button) findViewById(R.id.November);
        november.setOnClickListener(this);

        Button december=(Button) findViewById(R.id.December);
        december.setOnClickListener(this);

       switch (v.getId()) {
           case R.id.January:
                InputStream inputStream_january = getResources().openRawResource(R.raw.january);
                CSVFile csvFile_january = new CSVFile(inputStream_january);
                List<String[]> Event_List_january = csvFile_january.read();

                for (String[] Event_Data_january : Event_List_january) {
                    itemArrayAdapter.add(Event_Data_january);
                }
               january.setVisibility(View.GONE);
               february.setVisibility(View.GONE);
               march.setVisibility(View.GONE);
               april.setVisibility(View.GONE);
               may.setVisibility(View.GONE);
               june.setVisibility(View.GONE);
               july.setVisibility(View.GONE);
               august.setVisibility(View.GONE);
               september.setVisibility(View.GONE);
               october.setVisibility(View.GONE);
               november.setVisibility(View.GONE);
               december.setVisibility(View.GONE);


                break;

            case R.id.February:

                InputStream inputStream_february = getResources().openRawResource(R.raw.february);
                CSVFile csvFile_february = new CSVFile(inputStream_february);
                List<String[]> Event_List_february = csvFile_february.read();


                for (String[] Event_Data_february : Event_List_february) {
                    itemArrayAdapter.add(Event_Data_february);
                }
                january.setVisibility(View.GONE);
                february.setVisibility(View.GONE);
                march.setVisibility(View.GONE);
                april.setVisibility(View.GONE);
                may.setVisibility(View.GONE);
                june.setVisibility(View.GONE);
                july.setVisibility(View.GONE);
                august.setVisibility(View.GONE);
                september.setVisibility(View.GONE);
                october.setVisibility(View.GONE);
                november.setVisibility(View.GONE);
                december.setVisibility(View.GONE);

                break;

            case R.id.March:

                InputStream inputStream_march = getResources().openRawResource(R.raw.march);
                CSVFile csvFile_march = new CSVFile(inputStream_march);
                List<String[]> Event_List_march = csvFile_march.read();

                for (String[] Event_Data_march : Event_List_march) {
                    itemArrayAdapter.add(Event_Data_march);
                }
                january.setVisibility(View.GONE);
                february.setVisibility(View.GONE);
                march.setVisibility(View.GONE);
                april.setVisibility(View.GONE);
                may.setVisibility(View.GONE);
                june.setVisibility(View.GONE);
                july.setVisibility(View.GONE);
                august.setVisibility(View.GONE);
                september.setVisibility(View.GONE);
                october.setVisibility(View.GONE);
                november.setVisibility(View.GONE);
                december.setVisibility(View.GONE);

                break;

            case R.id.April:
                InputStream inputStream_april = getResources().openRawResource(R.raw.april);
                CSVFile csvFile_april = new CSVFile(inputStream_april);
                List<String[]> Event_List_april = csvFile_april.read();

                for (String[] Event_Data_april : Event_List_april) {
                    itemArrayAdapter.add(Event_Data_april);
                }
                january.setVisibility(View.GONE);
                february.setVisibility(View.GONE);
                march.setVisibility(View.GONE);
                april.setVisibility(View.GONE);
                may.setVisibility(View.GONE);
                june.setVisibility(View.GONE);
                july.setVisibility(View.GONE);
                august.setVisibility(View.GONE);
                september.setVisibility(View.GONE);
                october.setVisibility(View.GONE);
                november.setVisibility(View.GONE);
                december.setVisibility(View.GONE);

                break;


            case R.id.May:

                InputStream inputStream_may = getResources().openRawResource(R.raw.may);
                CSVFile csvFile_may = new CSVFile(inputStream_may);
                List<String[]> Event_List_may = csvFile_may.read();

                for (String[] Event_Data_may : Event_List_may) {
                    itemArrayAdapter.add(Event_Data_may);
                }
                january.setVisibility(View.GONE);
                february.setVisibility(View.GONE);
                march.setVisibility(View.GONE);
                april.setVisibility(View.GONE);
                may.setVisibility(View.GONE);
                june.setVisibility(View.GONE);
                july.setVisibility(View.GONE);
                august.setVisibility(View.GONE);
                september.setVisibility(View.GONE);
                october.setVisibility(View.GONE);
                november.setVisibility(View.GONE);
                december.setVisibility(View.GONE);

                break;

            case R.id.June:

                InputStream inputStream_june = getResources().openRawResource(R.raw.june);
                CSVFile csvFile_june = new CSVFile(inputStream_june);
                List<String[]> Event_List_june = csvFile_june.read();

                for (String[] Event_Data_june : Event_List_june) {
                    itemArrayAdapter.add(Event_Data_june);
                }
                january.setVisibility(View.GONE);
                february.setVisibility(View.GONE);
                march.setVisibility(View.GONE);
                april.setVisibility(View.GONE);
                may.setVisibility(View.GONE);
                june.setVisibility(View.GONE);
                july.setVisibility(View.GONE);
                august.setVisibility(View.GONE);
                september.setVisibility(View.GONE);
                october.setVisibility(View.GONE);
                november.setVisibility(View.GONE);
                december.setVisibility(View.GONE);

                break;

            case R.id.July:

                InputStream inputStream_july = getResources().openRawResource(R.raw.july);
                CSVFile csvFile_july = new CSVFile(inputStream_july);
                List<String[]> Event_List_july = csvFile_july.read();

                for (String[] Event_Data_july : Event_List_july) {
                    itemArrayAdapter.add(Event_Data_july);
                }
                january.setVisibility(View.GONE);
                february.setVisibility(View.GONE);
                march.setVisibility(View.GONE);
                april.setVisibility(View.GONE);
                may.setVisibility(View.GONE);
                june.setVisibility(View.GONE);
                july.setVisibility(View.GONE);
                august.setVisibility(View.GONE);
                september.setVisibility(View.GONE);
                october.setVisibility(View.GONE);
                november.setVisibility(View.GONE);
                december.setVisibility(View.GONE);

                break;

            case R.id.August:

                InputStream inputStream_august = getResources().openRawResource(R.raw.august);
                CSVFile csvFile_august = new CSVFile(inputStream_august);
                List<String[]> Event_List_august = csvFile_august.read();

                for (String[] Event_Data_august : Event_List_august) {
                    itemArrayAdapter.add(Event_Data_august);
                }
                january.setVisibility(View.GONE);
                february.setVisibility(View.GONE);
                march.setVisibility(View.GONE);
                april.setVisibility(View.GONE);
                may.setVisibility(View.GONE);
                june.setVisibility(View.GONE);
                july.setVisibility(View.GONE);
                august.setVisibility(View.GONE);
                september.setVisibility(View.GONE);
                october.setVisibility(View.GONE);
                november.setVisibility(View.GONE);
                december.setVisibility(View.GONE);

                break;

            case R.id.September:

                InputStream inputStream_september = getResources().openRawResource(R.raw.september);
                CSVFile csvFile_september = new CSVFile(inputStream_september);
                List<String[]> Event_List_september = csvFile_september.read();

                for (String[] Event_Data_september : Event_List_september) {
                    itemArrayAdapter.add(Event_Data_september);
                }
                january.setVisibility(View.GONE);
                february.setVisibility(View.GONE);
                march.setVisibility(View.GONE);
                april.setVisibility(View.GONE);
                may.setVisibility(View.GONE);
                june.setVisibility(View.GONE);
                july.setVisibility(View.GONE);
                august.setVisibility(View.GONE);
                september.setVisibility(View.GONE);
                october.setVisibility(View.GONE);
                november.setVisibility(View.GONE);
                december.setVisibility(View.GONE);

                break;

            case R.id.October:

                InputStream inputStream_october = getResources().openRawResource(R.raw.october);
                CSVFile csvFile_october = new CSVFile(inputStream_october);
                List<String[]> Event_List_october = csvFile_october.read();

                for (String[] Event_Data_october : Event_List_october) {
                    itemArrayAdapter.add(Event_Data_october);
                }
                january.setVisibility(View.GONE);
                february.setVisibility(View.GONE);
                march.setVisibility(View.GONE);
                april.setVisibility(View.GONE);
                may.setVisibility(View.GONE);
                june.setVisibility(View.GONE);
                july.setVisibility(View.GONE);
                august.setVisibility(View.GONE);
                september.setVisibility(View.GONE);
                october.setVisibility(View.GONE);
                november.setVisibility(View.GONE);
                december.setVisibility(View.GONE);

                break;

            case R.id.November:

                InputStream inputStream_november = getResources().openRawResource(R.raw.november);
                CSVFile csvFile_november = new CSVFile(inputStream_november);
                List<String[]> Event_List_november = csvFile_november.read();

                for (String[] Event_Data_november : Event_List_november) {
                    itemArrayAdapter.add(Event_Data_november);
                }
                january.setVisibility(View.GONE);
                february.setVisibility(View.GONE);
                march.setVisibility(View.GONE);
                april.setVisibility(View.GONE);
                may.setVisibility(View.GONE);
                june.setVisibility(View.GONE);
                july.setVisibility(View.GONE);
                august.setVisibility(View.GONE);
                september.setVisibility(View.GONE);
                october.setVisibility(View.GONE);
                november.setVisibility(View.GONE);
                december.setVisibility(View.GONE);

                break;

            case R.id.December:
                InputStream inputStream_december = getResources().openRawResource(R.raw.december);
                CSVFile csvFile_december = new CSVFile(inputStream_december);
                List<String[]> Event_List_december = csvFile_december.read();

                for (String[] Event_Data_december : Event_List_december) {
                    itemArrayAdapter.add(Event_Data_december);
                }
                january.setVisibility(View.GONE);
                february.setVisibility(View.GONE);
                march.setVisibility(View.GONE);
                april.setVisibility(View.GONE);
                may.setVisibility(View.GONE);
                june.setVisibility(View.GONE);
                july.setVisibility(View.GONE);
                august.setVisibility(View.GONE);
                september.setVisibility(View.GONE);
                october.setVisibility(View.GONE);
                november.setVisibility(View.GONE);
                december.setVisibility(View.GONE);

                break;
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.search, menu);

        return true;
    }


    @Override
    public void onBackPressed() {
        super.onBackPressed();
        startActivity(new Intent(List_Event.this, List_Event.class));
        finish();
    }


}



 ItemArrayAdapter.java

    package com.example.dell.display_event;

import android.content.Context;
import android.content.Intent;
import android.icu.text.StringSearch;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.List;
import android.widget.Button;

public class ItemArrayAdapter extends ArrayAdapter<String[]> {
    private List<String[]> Event_List = new ArrayList<String[]>();

    static class ItemViewHolder {
        TextView Days;
        TextView Events;
    }

    public ItemArrayAdapter(Context context, int textViewResourceId) {
        super(context, textViewResourceId);
    }

    @Override
    public void add(String[] object) {
        Event_List.add(object);
        super.add(object);
    }

    @Override
    public int getCount() {
        return this.Event_List.size();
    }

    @Override
    public String[] getItem(int index) {
        return this.Event_List.get(index);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = convertView;
        ItemViewHolder viewHolder;
        if (row == null) {
            LayoutInflater inflater = (LayoutInflater) this.getContext().
                    getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            row = inflater.inflate(R.layout.item_layout, parent, false);
            viewHolder = new ItemViewHolder();
            viewHolder.Days = (TextView) row.findViewById(R.id.Days);
            viewHolder.Events = (TextView) row.findViewById(R.id.Events);
            row.setTag(viewHolder);
        } else {
            viewHolder = (ItemViewHolder)row.getTag();

        }
        String[] day = getItem(position);
        viewHolder.Days.setText(day[0]);
        viewHolder.Events.setText(day[1]);
        return row;
    }


}

点击日历按钮后，效果很好

在这种情况下，后退按钮可以正常工作。

但是，我的意图是在列表视图中按下返回按钮时也返回首页。

同一事件的Android后退按钮

0 个答案: