Android学习笔记(三)

2017-12-27 14:25:03

复选框CheckBox概述

  1. 有两种状态

    选中状态（true）,未选中状态（false）

  2. 属性

    android: id="@+id/checkbox"
android: layout_width="wrap_content"
android: layout_height="wrap_content"
android: checked = "false"
android: text="男"

布局文件代码

<?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:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">


    <CheckBox
        android:checked="false"
        android:id="@+id/checkBox1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="python" />

</LinearLayout>

java文件代码

package com.example.nosay.myapplication;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.CheckBox;
import android.widget.CompoundButton;


public class MainActivity extends AppCompatActivity{

    private CheckBox checkBox;


    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.test1_main);

        //初始化checkBox
        checkBox = (CheckBox) findViewById(R.id.checkBox1);

        //通过设置checkBox的监听事件，来判断当前的checkBox是否被选中

        checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
                //通过onCheckedChanged来监听当前的checkBox是否被选中
                //如果b的值为true,说明是选中的，反之没选中
                if(b)
                {
                    //获得checkBox的文本内容
                    String s = checkBox.getText().toString();
                    Log.i("tag",s);
                }else{
                    Log.i("tag","取消了选中");
                }
            }
        });


    }

}
RadioGroup和RadioButton

  1. RadioGroup:

    RadioButton的一个集合，提供多选一的机制

  2. 属性

    android: orientation="vertical" //垂直排布
android: orientation="horizontal" //水平排布

决定当前RadioGroup中RadioButton以什么形式排列

布局文件代码如下：

<?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:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">



    <RadioGroup
        android:orientation="horizontal"
        android:id="@+id/radioGroup1"
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <RadioButton
            android:id="@+id/radioButton1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:checked="true"
            android:layout_weight="1"
            android:text="java" />

        <RadioButton
            android:id="@+id/radioButton2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="python" />

        <RadioButton
            android:id="@+id/radioButton3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="php" />
    </RadioGroup>
</LinearLayout>

java代码如下

package com.example.nosay.myapplication;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.widget.RadioGroup;


public class MainActivity extends AppCompatActivity implements RadioGroup.OnCheckedChangeListener{

    private RadioGroup radioGroup;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.test1_main);

        radioGroup = (RadioGroup) findViewById(R.id.radioGroup1);

        //实现RadioGroup的监听事件

        radioGroup.setOnCheckedChangeListener(this);


    }

    @Override
    public void onCheckedChanged(RadioGroup radioGroup, int i) {

        switch (i)
        {
            case R.id.radioButton1:
                Log.i("tag","你选择的是java");
                break;
            case R.id.radioButton2:
                Log.i("tag","你选择的是python");
                break;
            case R.id.radioButton3:
                Log.i("tag","你选择的是php");
                break;
        }
    }
}