Android_UI基础控件2

一、ImageView与ImageButton

<ImageView
        android:layout_width="300dp"
        android:layout_height="200dp"
        android:src="@drawable/ic_launcher_background"
        android:background="#222222"
        android:scaleType="fitCenter"/>

<ImageView
        android:layout_width="300dp"
        android:layout_height="200dp"
        android:src="@drawable/ic_launcher_background"
        android:background="#222222"
        android:scaleType="center"/>

<ImageView
        android:layout_width="300dp"
        android:layout_height="200dp"
        android:src="@drawable/ic_launcher_background"
        android:background="#222222"
        android:scaleType="fitXY"/>

二、CheckBox

public class MainActivity extends AppCompatActivity {
    private CheckBox cb_game,cb_travel,cb_read;
    private CheckBoxListener checkBoxListener;//3、定义这个监听器
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        setListener();

    }
    //4、
    // 在这个方法中实现监听
    private void setListener() {
        checkBoxListener = new CheckBoxListener();
        cb_game.setOnCheckedChangeListener(checkBoxListener);
        cb_travel.setOnCheckedChangeListener(checkBoxListener);
        cb_read.setOnCheckedChangeListener(checkBoxListener);

    }
//1、为了看着代码干净一点我们用这个初始化一下findviewbyid
    private void initView() {
        cb_game=findViewById(R.id.cb_game);
        cb_travel=findViewById(R.id.cb_travel);
        cb_read=findViewById(R.id.cb_read);
    }
//2、CheckBoxListener实现OnCheckedChangeListener监听器来监听选择框的改变isChecked当被选中时返回true反之false
    class CheckBoxListener implements CompoundButton.OnCheckedChangeListener{//注意使用CompoundButton的OnCheckedChangeListener
        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            //当选种状态发生变化时触发
            CheckBox checkBox = (CheckBox) buttonView;
            switch (checkBox.getId()){
                case R.id.cb_game:
                    Toast.makeText(MainActivity.this,"电竞："+isChecked,Toast.LENGTH_SHORT).show();
                    break;
                case R.id.cb_travel:
                    Toast.makeText(MainActivity.this,"旅游："+isChecked,Toast.LENGTH_SHORT).show();
                    break;
                case R.id.cb_read:
                    Toast.makeText(MainActivity.this,"阅读："+isChecked,Toast.LENGTH_SHORT).show();
                    break;

            }
        }
    }

}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <TextView
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="wrap_content"
            android:text="请选择爱好:"/>
        <CheckBox
            android:id="@+id/cb_game"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:text="电竞"
            android:checked="true"/>
        <CheckBox
            android:id="@+id/cb_travel"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:text="旅游"/>
        <CheckBox
            android:id="@+id/cb_read"
            android:layout_weight="1"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:text="阅读"/>
    </LinearLayout>

</LinearLayout>

三、RadioButton

1、RadioButton是圆形单选框

2、RadioGroup是个了以容纳多个RadioButton的容器

3、在RadioGroup中的RadioButton控件可以有多个，但同时有且仅有一个可以被选中

实现单选按钮

    在布局文件中定义RadioGroup

    在RadioGroup中添加RadioButton

    在Java代码中获取控件对象

    为对象添加监听器

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="请选择性别"/>
    <RadioGroup
        android:id="@+id/rg_sex"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        >
        <RadioButton
            android:id="@+id/rb_Male"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="男"/>
        <RadioButton
            android:id="@+id/rb_FeMale"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="女"/>

    </RadioGroup>
    
</LinearLayout>

public class MainActivity extends AppCompatActivity {
private RadioGroup rg;
private RadioButton rb_male,rb_female;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        rg = findViewById(R.id.rg_sex);
        rb_male = findViewById(R.id.rb_Male);
        rb_female = findViewById(R.id.rb_FeMale);
        rg.setOnCheckedChangeListener(new MyRadioButtonListener());
    }
    class MyRadioButtonListener implements RadioGroup.OnCheckedChangeListener{
        @Override
        public void onCheckedChanged(RadioGroup group, int checkedId) {
            //在状态改变时被触发
            switch (checkedId){
                case R.id.rb_FeMale:
                    Log.i("sex","当前用户选择"+rb_female.getText().toString());
                    break;
                case R.id.rb_Male:
                    Log.i("sex","当前用户选择"+rb_male.getText().toString());
                    break;
            }
        }
    }
}