第16天~ListView

Spinne-下拉式选单 跟ListView很像但是比较小

ListView单选+或选到很多样

https://ithelp.ithome.com.tw/upload/images/20220202/20119035WOulf0unwS.png

activity_main.xml档
https://ithelp.ithome.com.tw/upload/images/20220202/20119035yrXl3soyIG.png

<?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~
就会变成
https://ithelp.ithome.com.tw/upload/images/20220202/20119035ALM6CNk66G.png

colors.xml档

https://ithelp.ithome.com.tw/upload/images/20220202/20119035P4Nh1EokfL.png

<?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档

https://ithelp.ithome.com.tw/upload/images/20220202/20119035L8xRr3oWEb.png

<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">没有资料显示</string>
</resources>

开始来绑定Button的onClick
https://ithelp.ithome.com.tw/upload/images/20220202/201190358fDnc1PXBX.png

1-宣告变数
https://ithelp.ithome.com.tw/upload/images/20220202/20119035ykNPNNThUr.png

https://ithelp.ithome.com.tw/upload/images/20220202/20119035Mn1uTu3YWY.png

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 {
    //宣告变数
    Context context; //页面资讯
    String[] fastfood; //抓资源的字串
    ListAdapter adapter; //转换器转成字串
    ListView listView; //就是按钮listView
    TextView show;//选的东西呈现在文字栏位

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

    public void onClick(View view) {
    }
}

2-onCreate

https://ithelp.ithome.com.tw/upload/images/20220202/20119035rO4cGDIhUN.png

https://ithelp.ithome.com.tw/upload/images/20220202/20119035RdvAYX6KyG.png

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 {
    //宣告变数
    Context context; //页面资讯
    String[] fastfood; //抓资源的字串
    ListAdapter adapter; //转换器转成字串
    ListView listView; //就是按钮listView
    TextView show;//选的东西呈现在文字栏位

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

        context = this;//页面资讯
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml阵列里的名称


    }

    public void onClick(View view) {
    }
}

https://ithelp.ithome.com.tw/upload/images/20220202/20119035BZBLAiVFUK.png

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 {
    //宣告变数
    Context context; //页面资讯
    String[] fastfood; //抓资源的字串
    ListAdapter adapter; //转换器转成ListAdapter 父类 ArrayAdapter 子类转字串
    ListView listView; //就是按钮listView
    TextView show;//选的东西呈现在文字栏位

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

        context = this;//页面资讯
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml阵列里的名称

        //ListAdapter 父类 ArrayAdapter 子类.三个资讯:页面资讯.呈现怎样用多选.资料来源
        adapter = new ArrayAdapter<String>(
                context,
                android.R.layout.simple_list_item_multiple_choice,
                fastfood
        );


    }

    public void onClick(View view) {
    }
}

元件初始化-

https://ithelp.ithome.com.tw/upload/images/20220202/20119035O1Up2rQXmO.png

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 {
    //宣告变数
    Context context; //页面资讯
    String[] fastfood; //抓资源的字串
    ListAdapter adapter; //转换器转成ListAdapter 父类 ArrayAdapter 子类转字串
    ListView listView; //就是按钮listView
    TextView show;//选的东西呈现在文字栏位

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

        context = this;//页面资讯
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml阵列里的名称

        //ListAdapter 父类 ArrayAdapter 子类.三个资讯:页面资讯.呈现怎样用多选.资料来源
        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);

        //元件加侦听器


    }

    public void onClick(View view) {
    }
}

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

https://ithelp.ithome.com.tw/upload/images/20220202/20119035s79qE75l1e.png

4.1版本之後颜色要改成#______________

用网站转换-https://materialui.co/colors/teal/200

https://ithelp.ithome.com.tw/upload/images/20220202/20119035ak4TjGtByn.png

要两个在themes里的两个themes.xml档案都要改-

https://ithelp.ithome.com.tw/upload/images/20220202/20119035e8tpvhP79f.png

修改後的程序码:

<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>

https://ithelp.ithome.com.tw/upload/images/20220202/20119035SBU6hn5s3y.png

也可以用rgb的选色器
https://www.w3schools.com/colors/colors_picker.asp

要贴上#______ 才是色票

https://ithelp.ithome.com.tw/upload/images/20220202/201190354YKVebcpcJ.png

目前模拟器的显示:

https://ithelp.ithome.com.tw/upload/images/20220202/20119035WKcIXLhsrr.png

元件加侦听器-

https://ithelp.ithome.com.tw/upload/images/20220202/201190357jqriOLR3e.png

後面没自动跳出就要自己选

https://ithelp.ithome.com.tw/upload/images/20220202/20119035I5XFRDX2z2.png

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 {
    //宣告变数
    Context context; //页面资讯
    String[] fastfood; //抓资源的字串
    ListAdapter adapter; //转换器转成ListAdapter 父类 ArrayAdapter 子类转字串
    ListView listView; //就是按钮listView
    TextView show;//选的东西呈现在文字栏位

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

        context = this;//页面资讯
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml阵列里的名称

        //ListAdapter 父类 ArrayAdapter 子类.三个资讯:页面资讯.呈现怎样用多选.资料来源
        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);//加上选取
        listView.setSelector(R.color.lvcolor);//加上选取

        listView.setAdapter(adapter);

        //元件加侦听器

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


    }

    public void onClick(View view) {
    }
}

目前的显示:

https://ithelp.ithome.com.tw/upload/images/20220202/20119035JhHq4e3hAo.png

蒐集谁被点到放到文字栏位

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

https://ithelp.ithome.com.tw/upload/images/20220202/20119035W8ynXPFhHn.png

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 {
    //宣告变数
    Context context; //页面资讯
    String[] fastfood; //抓资源的字串
    ListAdapter adapter; //转换器转成ListAdapter 父类 ArrayAdapter 子类转字串
    ListView listView; //就是按钮listView
    TextView show;//选的东西呈现在文字栏位

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

        context = this;//页面资讯
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml阵列里的名称

        //ListAdapter 父类 ArrayAdapter 子类.三个资讯:页面资讯.呈现怎样用多选.资料来源
        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);//加上选取
        listView.setSelector(R.color.lvcolor);//加上选取

        listView.setAdapter(adapter);

        //元件加侦听器

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                //3种写法
                String s1 =parent.getItemAtPosition(position).toString(); //哪个位置被选到
                String s2 = adapter.getItem(position).toString();//透过adapter去取得item
                String s3 = fastfood[position];//找最源头

            }
        });


    }

    public void onClick(View view) {
    }
}

show 的文字栏位要初始化-

https://ithelp.ithome.com.tw/upload/images/20220202/20119035VQ1e9d4etW.png

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 {
    //宣告变数
    Context context; //页面资讯
    String[] fastfood; //抓资源的字串
    ListAdapter adapter; //转换器转成ListAdapter 父类 ArrayAdapter 子类转字串
    ListView listView; //就是按钮listView
    TextView show;//选的东西呈现在文字栏位

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

        context = this;//页面资讯
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml阵列里的名称

        //ListAdapter 父类 ArrayAdapter 子类.三个资讯:页面资讯.呈现怎样用多选.资料来源
        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);//加上选取
        listView.setSelector(R.color.lvcolor);//加上选取

        listView.setAdapter(adapter);

        //元件加侦听器

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                //3种写法
                String s1 =parent.getItemAtPosition(position).toString(); //哪个位置被选到
                String s2 = adapter.getItem(position).toString();//透过adapter去取得item
                String s3 = fastfood[position];//找最源头

            }
        });

        show =findViewById(R.id.emptyView);


    }

    public void onClick(View view) {
    }
}

宣告一个字串被点到-->然後回圈

https://ithelp.ithome.com.tw/upload/images/20220202/20119035BaicwCipYP.png

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 {
    //宣告变数
    Context context; //页面资讯
    String[] fastfood; //抓资源的字串
    ListAdapter adapter; //转换器转成ListAdapter 父类 ArrayAdapter 子类转字串
    ListView listView; //就是按钮listView
    TextView show;//选的东西呈现在文字栏位

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

        context = this;//页面资讯
        fastfood = getResources().getStringArray(R.array.fastfood);//取得strings.xml阵列里的名称

        //ListAdapter 父类 ArrayAdapter 子类.三个资讯:页面资讯.呈现怎样用多选.资料来源
        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);//加上选取
        listView.setSelector(R.color.lvcolor);//加上选取

        listView.setAdapter(adapter);

        //元件加侦听器

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                //3种写法
                String s1 =parent.getItemAtPosition(position).toString(); //哪个位置被选到
                String s2 = adapter.getItem(position).toString();//透过adapter去取得item
                String s3 = fastfood[position];//找最源头

            }
        });
        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);
    }
}

https://ithelp.ithome.com.tw/upload/images/20220202/20119035s9IrFASwBH.png


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