第16天~ListView

2021 iThome 鐵人賽

DAY 16

Mobile Development

就是從無到有寫app系列第 16 篇

13th鐵人賽

Tzu

2021-10-01 06:22:30

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Spinne-下拉式選單跟ListView很像但是比較小

ListView單選+或選到很多樣

activity_main.xml檔

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ListView
        android:id="@+id/listView"
        android:layout_width="368dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="50dp"
        android:layout_marginEnd="8dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/ok"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="50dp"
        android:layout_marginRight="8dp"
        android:onClick="onClick"
        android:text="Button"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/listView" />

    <TextView
        android:id="@+id/emptyView"
        android:layout_width="368dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="24dp"
        android:layout_marginEnd="8dp"
        android:text="@string/no_record"
        android:textAppearance="@style/TextAppearance.AppCompat.Large"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/ok" />



</androidx.constraintlayout.widget.ConstraintLayout>

把colors.xml跟strings.xml做好後~
就會變成

colors.xml檔

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#3F51B5</color>
    <color name="colorPrimaryDark">#303F9F</color>
    <color name="colorAccent">#FF4081</color>
    <color name="lvcolor">#77E5FF</color>
</resources>

strings.xml檔

<resources>
    <string name="app_name">MyListView01</string>
    <string-array name="fastfood">
        <item>COCA Light</item>
        <item>COCA Zero</item>
        <item>COCA</item>
        <item>French Fries</item>
        <item>Hamburger</item>
        <item>KFC</item>
        <item>Big Mac</item>
    </string-array>

    <string name="no_record">沒有資料顯示</string>
</resources>

開始來綁定Button的onClick

1-宣告變數

package com.huang.my_listview;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    //宣告變數
    Context context; //頁面資訊
    String[] fastfood; //抓資源的字串
    ListAdapter adapter; //轉換器轉成字串
    ListView listView; //就是按鈕listView
    TextView show;//選的東西呈現在文字欄位

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void onClick(View view) {
    }
}

2-onCreate

package com.huang.my_listview;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    //宣告變數
    Context context; //頁面資訊
    String[] fastfood; //抓資源的字串
    ListAdapter adapter; //轉換器轉成字串
    ListView listView; //就是按鈕listView
    TextView show;//選的東西呈現在文字欄位

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        context = this;//頁面資訊
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml陣列裡的名稱


    }

    public void onClick(View view) {
    }
}

package com.huang.my_listview;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    //宣告變數
    Context context; //頁面資訊
    String[] fastfood; //抓資源的字串
    ListAdapter adapter; //轉換器轉成ListAdapter 父類 ArrayAdapter 子類轉字串
    ListView listView; //就是按鈕listView
    TextView show;//選的東西呈現在文字欄位

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        context = this;//頁面資訊
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml陣列裡的名稱

        //ListAdapter 父類 ArrayAdapter 子類.三個資訊:頁面資訊.呈現怎樣用多選.資料來源
        adapter = new ArrayAdapter<String>(
                context,
                android.R.layout.simple_list_item_multiple_choice,
                fastfood
        );


    }

    public void onClick(View view) {
    }
}

元件初始化-

package com.huang.my_listview;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    //宣告變數
    Context context; //頁面資訊
    String[] fastfood; //抓資源的字串
    ListAdapter adapter; //轉換器轉成ListAdapter 父類 ArrayAdapter 子類轉字串
    ListView listView; //就是按鈕listView
    TextView show;//選的東西呈現在文字欄位

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        context = this;//頁面資訊
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml陣列裡的名稱

        //ListAdapter 父類 ArrayAdapter 子類.三個資訊:頁面資訊.呈現怎樣用多選.資料來源
        adapter = new ArrayAdapter<String>(
                context,
                android.R.layout.simple_list_item_multiple_choice,
                fastfood
        );

        //元件初始化
        listView =findViewById(R.id.listView);
        listView.setAdapter(adapter);

        //元件加偵聽器


    }

    public void onClick(View view) {
    }
}

先看效果-
error: resource color/purple_500 (aka com.huang.my_listview:color/purple_500) not found.

4.1版本之後顏色要改成#______________

用網站轉換-https://materialui.co/colors/teal/200

要兩個在themes裡的兩個themes.xml檔案都要改-

修改後的程式碼:

<resources xmlns:tools="http://schemas.android.com/tools">
    <!-- Base application theme. -->
    <style name="Theme.My_ListView" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
        <!-- Primary brand color. -->
        <item name="colorPrimary">#9C27B0</item>
        <item name="colorPrimaryVariant">#7B1FA2</item>
        <item name="colorOnPrimary">#FFFFFF</item>
        <!-- Secondary brand color. -->
        <item name="colorSecondary">#80CBC4</item>
        <item name="colorSecondaryVariant">#00796B</item>
        <item name="colorOnSecondary">#000000</item>
        <!-- Status bar color. -->
        <item name="android:statusBarColor" tools:targetApi="l">?attr/colorPrimaryVariant</item>
        <!-- Customize your theme here. -->
    </style>
</resources>

也可以用rgb的選色器
https://www.w3schools.com/colors/colors_picker.asp

要貼上#______ 才是色票

目前模擬器的顯示:

元件加偵聽器-

後面沒自動跳出就要自己選

package com.huang.my_listview;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    //宣告變數
    Context context; //頁面資訊
    String[] fastfood; //抓資源的字串
    ListAdapter adapter; //轉換器轉成ListAdapter 父類 ArrayAdapter 子類轉字串
    ListView listView; //就是按鈕listView
    TextView show;//選的東西呈現在文字欄位

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        context = this;//頁面資訊
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml陣列裡的名稱

        //ListAdapter 父類 ArrayAdapter 子類.三個資訊:頁面資訊.呈現怎樣用多選.資料來源
        adapter = new ArrayAdapter<String>(
                context,
                android.R.layout.simple_list_item_multiple_choice,
                fastfood
        );

        //元件初始化
        listView =findViewById(R.id.listView);

        listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);//加上選取
        listView.setSelector(R.color.lvcolor);//加上選取

        listView.setAdapter(adapter);

        //元件加偵聽器

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                
            }
        });


    }

    public void onClick(View view) {
    }
}

目前的顯示:

蒐集誰被點到放到文字欄位

adapterView改成parent就是整體
int i, long l改成 int position, long id

package com.huang.my_listview;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    //宣告變數
    Context context; //頁面資訊
    String[] fastfood; //抓資源的字串
    ListAdapter adapter; //轉換器轉成ListAdapter 父類 ArrayAdapter 子類轉字串
    ListView listView; //就是按鈕listView
    TextView show;//選的東西呈現在文字欄位

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        context = this;//頁面資訊
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml陣列裡的名稱

        //ListAdapter 父類 ArrayAdapter 子類.三個資訊:頁面資訊.呈現怎樣用多選.資料來源
        adapter = new ArrayAdapter<String>(
                context,
                android.R.layout.simple_list_item_multiple_choice,
                fastfood
        );

        //元件初始化
        listView =findViewById(R.id.listView);

        listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);//加上選取
        listView.setSelector(R.color.lvcolor);//加上選取

        listView.setAdapter(adapter);

        //元件加偵聽器

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                //3種寫法
                String s1 =parent.getItemAtPosition(position).toString(); //哪個位置被選到
                String s2 = adapter.getItem(position).toString();//透過adapter去取得item
                String s3 = fastfood[position];//找最源頭

            }
        });


    }

    public void onClick(View view) {
    }
}

show 的文字欄位要初始化-

package com.huang.my_listview;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    //宣告變數
    Context context; //頁面資訊
    String[] fastfood; //抓資源的字串
    ListAdapter adapter; //轉換器轉成ListAdapter 父類 ArrayAdapter 子類轉字串
    ListView listView; //就是按鈕listView
    TextView show;//選的東西呈現在文字欄位

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        context = this;//頁面資訊
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml陣列裡的名稱

        //ListAdapter 父類 ArrayAdapter 子類.三個資訊:頁面資訊.呈現怎樣用多選.資料來源
        adapter = new ArrayAdapter<String>(
                context,
                android.R.layout.simple_list_item_multiple_choice,
                fastfood
        );

        //元件初始化
        listView =findViewById(R.id.listView);

        listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);//加上選取
        listView.setSelector(R.color.lvcolor);//加上選取

        listView.setAdapter(adapter);

        //元件加偵聽器

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                //3種寫法
                String s1 =parent.getItemAtPosition(position).toString(); //哪個位置被選到
                String s2 = adapter.getItem(position).toString();//透過adapter去取得item
                String s3 = fastfood[position];//找最源頭

            }
        });

        show =findViewById(R.id.emptyView);


    }

    public void onClick(View view) {
    }
}

宣告一個字串被點到-->然後迴圈

package com.huang.my_listview;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {
    //宣告變數
    Context context; //頁面資訊
    String[] fastfood; //抓資源的字串
    ListAdapter adapter; //轉換器轉成ListAdapter 父類 ArrayAdapter 子類轉字串
    ListView listView; //就是按鈕listView
    TextView show;//選的東西呈現在文字欄位

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        context = this;//頁面資訊
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml陣列裡的名稱

        //ListAdapter 父類 ArrayAdapter 子類.三個資訊:頁面資訊.呈現怎樣用多選.資料來源
        adapter = new ArrayAdapter<String>(
                context,
                android.R.layout.simple_list_item_multiple_choice,
                fastfood
        );

        //元件初始化
        listView =findViewById(R.id.listView);

        listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);//加上選取
        listView.setSelector(R.color.lvcolor);//加上選取

        listView.setAdapter(adapter);

        //元件加偵聽器

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                //3種寫法
                String s1 =parent.getItemAtPosition(position).toString(); //哪個位置被選到
                String s2 = adapter.getItem(position).toString();//透過adapter去取得item
                String s3 = fastfood[position];//找最源頭

            }
        });
        show =findViewById(R.id.emptyView);
    }

    public void onClick(View view) {

        String all = "";
        for(int i=0; i<fastfood.length; i++){
            if(listView.isItemChecked(i)){
                all += fastfood[i]+" / ";
            }
        }
        show.setText(all);
    }
}