Android學習筆記17---單選按鈕&複選框

單選按鈕，RadioGroup通常和RadioButton配合起來使用。

常見的選性別操作。用一下兩種方式實現。

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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="com.amy.radiogrouptest.MainActivity">

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="性別："
            android:height="50px"/>
        <RadioGroup
            android:id="@+id/radioGroup1"
            android:orientation="horizontal"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">
            <RadioButton
                android:id="@+id/radio0"
                android:text="男"
                android:checked="true"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" />
            <RadioButton
                android:id="@+id/radio1"
                android:text="女"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" />
        </RadioGroup>
        <Button
            android:id="@+id/button1"
            android:text="提交"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />
    </LinearLayout>

</android.support.constraint.ConstraintLayout>

MainActivity.java

package com.amy.radiogrouptest;

import android.provider.MediaStore;
import android.support.annotation.IdRes;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.RadioButton;
import android.widget.RadioGroup;

public class MainActivity extends AppCompatActivity {

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

        /**
         *方式一：在選擇單選按鈕時獲取值
         */
        //獲取單選按鈕組
        final RadioGroup sex = (RadioGroup) findViewById(R.id.radioGroup1);
        sex.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, @IdRes int checkedId) {
                //獲取被選擇的單選按鈕
                RadioButton r = (RadioButton) findViewById(checkedId);
                Log.e("單選按鈕","您選擇的是"+r.getText());
            }
        });

        /**
         * 方式二：在單擊“提交”按鈕時獲取
         */
        //獲取提交按鈕
        Button button = (Button) findViewById(R.id.button1);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //通過for循環遍歷單擊按鈕組
                for (int i=0;i<sex.getChildCount();i++) {
                    RadioButton r = (RadioButton) sex.getChildAt(i);
                    //判斷單選按鈕是否被選中
                    if (r.isChecked()) {
                        Log.e("單選按鈕","性別："+r.getText());
                        break;
                    }
                }
            }
        });
    }
}

效果圖：

複選框，在選項前面默認顯示成一個小方塊，與單選按鈕不同的是，它爲每一個複選框都提供一個選中和不選中兩種狀態。

主要應用在選愛好，課程，購物車裏面的種種。

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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="com.amy.checkbox.MainActivity">

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="368dp"
        android:layout_height="wrap_content"
        tools:layout_editor_absoluteY="0dp"
        tools:layout_editor_absoluteX="8dp">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="愛好"
            android:textSize="16sp"
            android:width="100px"
            android:gravity="right"
            android:height="50px"/>
        <CheckBox
            android:id="@+id/like1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Java" />
        <CheckBox
            android:id="@+id/like2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="C++" />
        <CheckBox
            android:id="@+id/like3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Python" />
        <Button
            android:id="@+id/button1"
            android:text="提交"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

    </LinearLayout>

</android.support.constraint.ConstraintLayout>

MainActivity.java

package com.amy.checkbox;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private Button button;
    private CompoundButton.OnCheckedChangeListener onCheckedChangeListener = new CompoundButton.OnCheckedChangeListener() {
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            if (isChecked) {
                //判斷複選框是否被選中
                Log.e("複選框","選中了["+buttonView.getText().toString()+"]");
            }
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final CheckBox like1 = (CheckBox) findViewById(R.id.like1);
        final CheckBox like2 = (CheckBox) findViewById(R.id.like2);
        final CheckBox like3 = (CheckBox) findViewById(R.id.like3);
        //爲三個複選框添加狀態改變監聽器
        like1.setOnCheckedChangeListener(onCheckedChangeListener);
        like2.setOnCheckedChangeListener(onCheckedChangeListener);
        like3.setOnCheckedChangeListener(onCheckedChangeListener);

        //獲取提交按鈕，併爲其添加單擊事件監聽
        button = (Button) findViewById(R.id.button1);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String likes = "";
                if (like1.isChecked())likes += like1.getText().toString()+" ";
                if (like2.isChecked())likes += like2.getText().toString()+" ";
                if (like3.isChecked())likes += like3.getText().toString()+" ";
                //顯示被選中的內容
                Toast.makeText(MainActivity.this,likes,Toast.LENGTH_SHORT).show();
            }
        });
    }
}

效果圖：

這部分比較簡單，肯能是還沒有到難得時候，暗自開心一會。畢竟幸福的日子總是那麼短暫