第15天~Spinner

Spinne-下拉式选单跟ListView很像但是比较小

不是Menu

做MainActivity.xml档

spinner反红还是可以用

做res里的 strings.xml档

<resources>
    <string name="app_name">Spinner</string>

    <string-array name="meal">
        <item>美式汉堡</item>
        <item>猪肉汉堡</item>
        <item>牛肉汉堡</item>
        <item>泡菜汉堡</item>
        <item>米汉堡</item>
    </string-array>

    <string-array name="drink">
        <item>可乐</item>
        <item>绿茶</item>
        <item>奶茶</item>
        <item>果汁</item>
    </string-array>


</resources>

sp_meal-用绑定
MainActivity.xml档的资料跟谁绑定看entries

画面的"三角形"是不能点的~

@是res
array阵列
/meal里面的样子

1-sp_meal-用绑定

2-sp_drink-在java档-宣告

String sp1,sp2,sp3;蒐集点到的字串

package com.huang.my_spinner;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.Button;
import android.widget.Spinner;

public class MainActivity extends AppCompatActivity {

    //宣告变数
    Button button;
    Spinner sp_meal,sp_drink,sp_dessert;
    String sp1,sp2,sp3;


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

把sp_meal,sp_drink,sp_dessert;初始化完.因为sp_meal已经做完了，所以做後面sp_drink,sp_dessert

ArrayAdapter adapter = new ArrayAdapter<>(); 完成转换的内容

安卓的前後都要写+使用下拉参数 android的a要小写

package com.huang.my_spinner;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;

public class MainActivity extends AppCompatActivity {

    //宣告变数
    Button button;
    Spinner sp_meal,sp_drink,sp_dessert;
    String sp1,sp2,sp3;


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

        sp_meal =findViewById(R.id.sp_meal);
        sp_drink = findViewById(R.id.sp_drink);
        sp_dessert = findViewById(R.id.sp_dessert);

        //第二组:取得array资源
        //取得DATA-->转换-->元件呈现
        String[] drink =getResources().getStringArray(R.array.drink);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(
                MainActivity.this,
                android.R.layout.simple_spinner_dropdown_item,
                drink

        );

        //第三组


    }
}

在元件中呈现

package com.huang.my_spinner;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;

public class MainActivity extends AppCompatActivity {

    //宣告变数
    Button button;
    Spinner sp_meal,sp_drink,sp_dessert;
    String sp1,sp2,sp3;


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

        sp_meal =findViewById(R.id.sp_meal);
        sp_drink = findViewById(R.id.sp_drink);
        sp_dessert = findViewById(R.id.sp_dessert);

        //第二组:取得array资源
        //取得DATA-->转换-->元件呈现
        String[] drink =getResources().getStringArray(R.array.drink);

        //进行转换成指定的格式
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(
                MainActivity.this,
                android.R.layout.simple_spinner_dropdown_item,
                drink

        );
        //在元件中呈现
        sp_drink.setAdapter(adapter);



        //第三组


    }
}

模拟器看

到目前是纯粹看-

3-sp_dessert-汇入res

package com.huang.my_spinner;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;

public class MainActivity extends AppCompatActivity {

    //宣告变数
    Button button;
    Spinner sp_meal,sp_drink,sp_dessert;
    String sp1,sp2,sp3;


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

        sp_meal =findViewById(R.id.sp_meal);
        sp_drink = findViewById(R.id.sp_drink);
        sp_dessert = findViewById(R.id.sp_dessert);

        //第二组:取得array资源
        //取得DATA-->转换-->元件呈现
        String[] drink =getResources().getStringArray(R.array.drink);

        //进行转换成指定的格式
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(
                MainActivity.this,
                android.R.layout.simple_spinner_dropdown_item,
                drink

        );
        //在元件中呈现
        sp_drink.setAdapter(adapter);

        //第三组
        String[] dessert={"布丁","饼乾","CAKE","不要甜点"};
        ArrayAdapter<String> adapter1 = new ArrayAdapter<String>(
                MainActivity.this,
                android.R.layout.simple_spinner_dropdown_item,
                dessert

        );
        //在元件中呈现
        sp_dessert.setAdapter(adapter1);


    }
}

改下拉字的大小+呈现也是要用java档-新增layout资料夹

拉一个textView近来改宽30dp-上下左右不要绑

字的大小

背景色-background--选color

改layout_margin是10dp

字的颜色-textColor

再来到程序码去修改~

画线的要搬家

把其他的删掉-剩下长这样

有出错就是有重复

<?xml version="1.0" encoding="utf-8"?>


    <TextView
        xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="30dp"
        android:layout_margin="10dp"
        android:background="@color/purple_200"
        android:text="TextView"
        android:textAppearance="@style/TextAppearance.AppCompat.Large"
        android:textColor="@color/design_default_color_error"
        tools:layout_editor_absoluteX="16dp"
        tools:layout_editor_absoluteY="16dp" />

把第3组加入刚刚设计的

package com.huang.my_spinner;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;

public class MainActivity extends AppCompatActivity {

    //宣告变数
    Button button;
    Spinner sp_meal,sp_drink,sp_dessert;
    String sp1,sp2,sp3;


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

        sp_meal =findViewById(R.id.sp_meal);
        sp_drink = findViewById(R.id.sp_drink);
        sp_dessert = findViewById(R.id.sp_dessert);

        //第二组:取得array资源
        //取得DATA-->转换-->元件呈现
        String[] drink =getResources().getStringArray(R.array.drink);

        //进行转换成指定的格式
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(
                MainActivity.this,
                android.R.layout.simple_spinner_dropdown_item,
                drink

        );
        //在元件中呈现
        sp_drink.setAdapter(adapter);

        //第三组
        String[] dessert={"布丁","饼乾","CAKE","不要甜点"};
        ArrayAdapter<String> adapter1 = new ArrayAdapter<String>(
                MainActivity.this,
                android.R.layout.simple_spinner_dropdown_item,
                dessert

        );
        //在元件中呈现
        adapter1.setDropDownViewResource(R.layout.mylayout);
        sp_dessert.setAdapter(adapter1);
            }
}

只要看第一个com就好..其他是系统测试用-

按钮完成-
1-初始化按钮
2-加侦听器

3-选到的项目转成字串

package com.huang.my_spinner;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    //宣告变数
    Button button;
    Spinner sp_meal,sp_drink,sp_dessert;
    String sp1,sp2,sp3;


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

        sp_meal =findViewById(R.id.sp_meal);
        sp_drink = findViewById(R.id.sp_drink);
        sp_dessert = findViewById(R.id.sp_dessert);

        //第二组:取得array资源
        //取得DATA-->转换-->元件呈现
        String[] drink =getResources().getStringArray(R.array.drink);

        //进行转换成指定的格式
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(
                MainActivity.this,
                android.R.layout.simple_spinner_dropdown_item,
                drink

        );
        //在元件中呈现
        sp_drink.setAdapter(adapter);

        //第三组
        String[] dessert={"布丁","饼乾","CAKE","不要甜点"};
        ArrayAdapter<String> adapter1 = new ArrayAdapter<String>(
                MainActivity.this,
                android.R.layout.simple_spinner_dropdown_item,
                dessert

        );
        //在元件中呈现
        adapter1.setDropDownViewResource(R.layout.mylayout);
        sp_dessert.setAdapter(adapter1);

        //Button
        button = findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //第1组
                sp1 =sp_meal.getSelectedItem().toString();
                Toast.makeText(MainActivity.this,sp1,Toast.LENGTH_SHORT).show();

                //第2组
                sp2 =sp_drink.getSelectedItem().toString();
                Toast.makeText(MainActivity.this,sp2,Toast.LENGTH_SHORT).show();

                //第3组
                sp3 =sp_dessert.getSelectedItem().toString();
                Toast.makeText(MainActivity.this,sp3,Toast.LENGTH_SHORT).show();

            }
        });

        }
}

Toast也是要用手机测试才看的到-