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Android 综合练习Task3

程序员文章站 2022-06-21 19:16:23
Android 综合练习Task3题目要求编写一个程序，1个TextView(用于显示学号姓名)、1个ListView。ListView是风景点的地点名称和风景图片（适配器需要改写）。在所描述功能的基础上，对ListView增加上下文菜单（修改、删除、新增三个功能），修改功能支持对风景地点改名称和图片重选（弹出的对话框中有图文并茂的GridView），并且改完名称后，ListView的名称也会被修改；删除功能则对该风景删除，ListView也会相应更新；新增功能能在弹出的对话框中选择GridView显示...

Android 综合练习Task3

题目要求

编写一个程序，1个TextView(用于显示学号姓名)、1个ListView。ListView是风景点的地点名称和风景图片（适配器需要改写）。在所描述功能的基础上，对ListView增加上下文菜单（修改、删除、新增三个功能），修改功能支持对风景地点改名称和图片重选（弹出的对话框中有图文并茂的GridView），并且改完名称后，ListView的名称也会被修改；删除功能则对该风景删除，ListView也会相应更新；新增功能能在弹出的对话框中选择GridView显示的风景进行添加。选项菜单的功能则为：增加风景、重置两个功能。重置功能则将ListView中的风景列表恢复成程序启动时的状态。修改和新增功能弹出的对话框，第一行为EditText和ImageView，第二行为GridView，并有确定和取消按钮。
Android 综合练习Task3

分析

主界面只有一个TextView和一个Listview
其中Listview需要自己设置样式 为 img + textview
主界面需要同添加menu 含有2个功能
Alert的内容也需要设置样式 EditText + image + Gridview

主界面

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Show my name and id" />

    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>

row_Listview

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="horizontal">

    <ImageView
        android:id="@+id/row_img"
        android:layout_width="120dp"
        android:layout_height="120dp"
        android:scaleType="centerCrop"
        app:srcCompat="@drawable/da_luo_shan" />

    <TextView
        android:id="@+id/row_tv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="15dp"
        android:textSize="20sp"
        android:text="大罗山" />
</LinearLayout>

menu

一个是右上角的menu,一个是点击ListView中内容出现的menu

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:id="@+id/detail_modify"
        android:title="修改" />
    <item
        android:id="@+id/detail_delete"
        android:title="删除" />
    <item
        android:id="@+id/detail_add"
        android:title="增加" />
</menu>

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:id="@+id/main_reset"
        android:title="重置" />
    <item
        android:id="@+id/main_add"
        android:title="增加风景" />
</menu>

Alert内容

这个先放着

实现步骤

我们一步一步的来实现功能
根据我的思路,先实现以下ListView的布局,对前面的知识进行以简单的回顾

ListView内容实现

City.Class

package com.example.tty_task3_example;

public class City {
    private String name;
    private int img_id;

    public City(String name, int img_id) {
        this.name = name;
        this.img_id = img_id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getImg_id() {
        return img_id;
    }

    public void setImg_id(int img_id) {
        this.img_id = img_id;
    }
}

CityAdapter.Class

package com.example.tty_task3_example;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

import java.util.ArrayList;

public class CityAdapter extends ArrayAdapter<City> {
    private Context context;
    private ArrayList<City> list;

    public CityAdapter(@NonNull Context context, ArrayList<City> list) {
        super(context, android.R.layout.simple_list_item_1, list);
        this.list = list;
        this.context = context;
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        View v;
        if (convertView == null) {
            v = LayoutInflater.from(context).inflate(R.layout.row_lv, null, false);
        } else {
            v = convertView;
        }
        City city = list.get(position);
        ImageView img = v.findViewById(R.id.row_img);
        TextView tv = v.findViewById(R.id.row_tv);
        img.setImageResource(city.getImg_id());
        tv.setText(city.getName());
        return v;
    }
}

包含部分功能的MainActivity.Class

package com.example.tty_task3_example;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.ContextMenu;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    ArrayList<City> list;
    ArrayAdapter<City> adapter;
    ListView lv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.my_main);
        lv = findViewById(R.id.main_lv);
        list = new ArrayList<>();
        list = init_list();
        adapter = new CityAdapter(this, list);
        lv.setAdapter(adapter);
        registerForContextMenu(lv);
    }

    private ArrayList<City> init_list() {
        City city1 = new City("长城", R.drawable.great_wall);
        City city2 = new City("大罗山", R.drawable.da_luo_shan);
        list.add(city1);
        list.add(city2);
        return list;
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
        super.onCreateContextMenu(menu, v, menuInfo);
        getMenuInflater().inflate(R.menu.detai_menu, menu);
    }

    @Override
    public boolean onContextItemSelected(@NonNull MenuItem item) {
        AdapterView.AdapterContextMenuInfo menuInfo = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
        int position = menuInfo.position;
        switch (item.getItemId()) {
            case R.id.detail_add:
                break;
            case R.id.detail_delete:
                list.remove(position);
                adapter.notifyDataSetChanged();
                break;
            case R.id.detail_modify:
                break;
        }
        return super.onContextItemSelected(item);
    }
}

增加和修改的内容涉及到Alert页面,这个我打算后面再写,这里仅仅实现了删除的功能
初始界面我打算放如下两个Item,定义在init_list的方法中
Android 综合练习Task3
下面我打算添加一下右上角的菜单

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main_menu, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        switch (item.getItemId()) {
            case R.id.main_add:
                break;
            case R.id.main_reset:
                list = init_list();
                adapter.notifyDataSetChanged();
                break;
        }
        return super.onOptionsItemSelected(item);
    }

接下来就是Alert页面了

Alert页面

最上面一层是 EditText和Image
下面是GridView
其中GridView中的Item要自己定义

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:orientation="horizontal">

        <EditText
            android:id="@+id/alert_et"
            android:layout_width="200dp"
            android:layout_height="wrap_content"
            android:paddingLeft="20dp"
            android:maxLines="1"
            android:inputType="textPersonName"
            android:text="大罗山" />

        <ImageView
            android:id="@+id/alert_img"
            android:layout_width="60dp"
            android:layout_height="40dp"
            android:scaleType="centerCrop"
            app:srcCompat="@drawable/da_luo_shan" />
    </LinearLayout>

    <GridView
        android:id="@+id/alert_gv"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:numColumns="2"
        android:stretchMode="columnWidth" />
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/row_gv_img"
        android:layout_width="100dp"
        android:layout_height="60dp"
        android:scaleType="centerCrop"
        app:srcCompat="@drawable/great_wall" />

    <TextView
        android:id="@+id/row_gv_tv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:padding="5dp"
        android:text="长城" />
</LinearLayout>

为添加功能创造一个函数add_more
第一次写的时候忘记加bl.setView(v);了,找了半天才发现

    private void add_more() {
        gv_list = init_gv_list();
        AlertDialog.Builder bl = new AlertDialog.Builder(this);
        bl.setTitle("增加内容");
        View v = LayoutInflater.from(this).inflate(R.layout.alert_detail, null, false);
        bl.setView(v);
        final EditText et = v.findViewById(R.id.alert_et);
        final ImageView img = v.findViewById(R.id.alert_img);
        GridView gv = v.findViewById(R.id.alert_gv);
        final GridViewAdapter gv_adpter = new GridViewAdapter(this, gv_list);
        gv.setAdapter(gv_adpter);
        gv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                City city = gv_adpter.getItem(position);
                et.setText(city.getName());
                img.setImageResource(city.getImg_id());
            }
        });
        bl.setPositiveButton("确认", null).setNegativeButton("取消", null).create().show();
    }

可以基本实现如下的效果
Android 综合练习Task3
可以看到,虽然出现了选择框,但是点击确认后没什么用,所以接下来要继续编写setPositiveButton的内容

String name = et.getText().toString();
list.add(new City(name, img_id[0]));
adapter.notifyDataSetChanged();

修改和新增的功能区别在与,点击修改的时候Editview里面要出现点击的那个城市的信息
而新增的时候需要有默认的名字和图片
Android 综合练习Task3

全代码

因为java学的不是很好,所以很多地方写的很粗糙,之后复习的时候会优化一下

package com.example.tty_task3_example;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;

import android.content.DialogInterface;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.ListView;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
    ArrayList<City> list, gv_list;
    ArrayAdapter<City> adapter;
    ListView lv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.my_main);
        lv = findViewById(R.id.main_lv);
        gv_list = new ArrayList<>();
        list = new ArrayList<>();
        list = init_list();
        adapter = new CityAdapter(this, list);
        lv.setAdapter(adapter);
        registerForContextMenu(lv);
    }

    private ArrayList<City> init_gv_list() {
        gv_list.clear();
        City city1 = new City("西湖", R.drawable.west_lake);
        City city2 = new City("灵隐寺", R.drawable.ling_yin_temple);
        City city3 = new City("*", R.drawable.the_imperial_palace);
        City city4 = new City("南溪河", R.drawable.nan_xi_river);
        gv_list.add(city1);
        gv_list.add(city2);
        gv_list.add(city3);
        gv_list.add(city4);
        return gv_list;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main_menu, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        switch (item.getItemId()) {
            case R.id.main_add:
//                增加功能
                add_more();
                break;
            case R.id.main_reset:
                list = init_list();
                adapter.notifyDataSetChanged();
                break;
        }
        return super.onOptionsItemSelected(item);
    }

    private ArrayList<City> init_list() {
        list.clear();
        City city1 = new City("长城", R.drawable.great_wall);
        City city2 = new City("大罗山", R.drawable.da_luo_shan);
        list.add(city1);
        list.add(city2);
        return list;
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
        super.onCreateContextMenu(menu, v, menuInfo);
        getMenuInflater().inflate(R.menu.detai_menu, menu);
    }

    @Override
    public boolean onContextItemSelected(@NonNull MenuItem item) {
        AdapterView.AdapterContextMenuInfo menuInfo = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
        int position = menuInfo.position;
        switch (item.getItemId()) {
            case R.id.detail_add:
                add_more();
//                增加功能
                break;
            case R.id.detail_delete:
                list.remove(position);
                adapter.notifyDataSetChanged();
                break;
            case R.id.detail_modify:
                City city2 = list.get(position);
//                修改功能
                modify(city2);
                break;
        }
        return super.onContextItemSelected(item);
    }

    private void modify(City city){
        gv_list = init_gv_list();
        AlertDialog.Builder bl = new AlertDialog.Builder(this);
        bl.setTitle("增加内容");
        View v = LayoutInflater.from(this).inflate(R.layout.alert_detail, null, false);
        bl.setView(v);
        final EditText et = v.findViewById(R.id.alert_et);
        et.setText(city.getName());
        final ImageView img = v.findViewById(R.id.alert_img);
        img.setImageResource(city.getImg_id());
        GridView gv = v.findViewById(R.id.alert_gv);
        final GridViewAdapter gv_adpter = new GridViewAdapter(this, gv_list);
        final int[] img_id = new int[1];
        gv.setAdapter(gv_adpter);
        gv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                City gv_city = gv_adpter.getItem(position);
                et.setText(gv_city.getName());
                img_id[0] = gv_city.getImg_id();
                img.setImageResource(gv_city.getImg_id());
            }
        });
        bl.setPositiveButton("确认", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                String name = et.getText().toString();
                list.add(new City(name, img_id[0]));
                adapter.notifyDataSetChanged();
            }
        }).setNegativeButton("取消", null).create().show();
    }


    private void add_more() {
        gv_list = init_gv_list();
        AlertDialog.Builder bl = new AlertDialog.Builder(this);
        bl.setTitle("增加内容");
        View v = LayoutInflater.from(this).inflate(R.layout.alert_detail, null, false);
        bl.setView(v);
        final EditText et = v.findViewById(R.id.alert_et);
        et.setText("钱江");
        final ImageView img = v.findViewById(R.id.alert_img);
        img.setImageResource(R.drawable.qian_jiang_cbd);
        GridView gv = v.findViewById(R.id.alert_gv);
        final GridViewAdapter gv_adpter = new GridViewAdapter(this, gv_list);
        final int[] img_id = new int[1];
        img_id[0] = R.drawable.qian_jiang_cbd;
        gv.setAdapter(gv_adpter);
        gv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                City gv_city = gv_adpter.getItem(position);
                et.setText(gv_city.getName());
                img_id[0] = gv_city.getImg_id();
                img.setImageResource(gv_city.getImg_id());
            }
        });
        bl.setPositiveButton("确认", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                String name = et.getText().toString();
                list.add(new City(name, img_id[0]));
                adapter.notifyDataSetChanged();
            }
        }).setNegativeButton("取消", null).create().show();
    }
}

本文地址：https://blog.csdn.net/Weary_PJ/article/details/108728039

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