一、各自的功能及使用场景
ImageView：用于展示一张图片，例如商品展示；
Switch：开关、控制器，常用于app设置中；
DatePicker：日期选择器，多用于订阅类的服务和功能
二、简单使用
1、布局部分
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:gravity="center"
android:orientation="vertical">
<ImageView
android:id="@+id/iv_img"
android:layout_width="100dp"
android:layout_height="100dp" />
<Button
android:id="@+id/btn_todo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="CLICK"/>
<Switch
android:id="@+id/s_toggle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:checked="true"/>
<TextView
android:id="@+id/tv_date"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
<DatePicker
android:id="@+id/dp_date"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>2、代码部分
private TextView tvDate;
private Button btnTodo;
private Switch sToggle;
private DatePicker dpDate;
private ImageView ivImg;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
setListener();
ivImg.setImageResource(R.drawable.ic_launcher_foreground);
}
private void setListener() {
btnTodo.setOnClickListener(v -> {
Toast.makeText(this, "按钮被点击", Toast.LENGTH_SHORT).show();
});
sToggle.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
btnTodo.setEnabled(isChecked);
}
});
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
dpDate.setOnDateChangedListener(new DatePicker.OnDateChangedListener() {
@Override
public void onDateChanged(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
tvDate.setText(year+"年"+(monthOfYear+1)+"月"+dayOfMonth+"日");
}
});
}
}
private void initView() {
tvDate=findViewById(R.id.tv_date);
btnTodo=findViewById(R.id.btn_todo);
sToggle=findViewById(R.id.s_toggle);
dpDate=findViewById(R.id.dp_date);
ivImg=findViewById(R.id.iv_img);
}
}代码中，我通过sToggle来控制btnTodo是否可点击，将dpDate获取到的日期用tvDate展示，之所以会+1是因为月份获取到的数字是从0开始的
三、运行效果
四、官网对于上述控件的属性介绍
1、ImageView
android:adjustViewBounds | Set this to true if you want the ImageView to adjust its bounds to preserve the aspect ratio of its drawable. |
android:baseline | The offset of the baseline within this view. |
android:baselineAlignBottom | If true, the image view will be baseline aligned with based on its bottom edge. |
android:cropToPadding | If true, the image will be cropped to fit within its padding. |
android:maxHeight | An optional argument to supply a maximum height for this view. |
android:maxWidth | An optional argument to supply a maximum width for this view. |
android:scaleType | Controls how the image should be resized or moved to match the size of this ImageView. |
android:src | Sets a drawable as the content of this ImageView. |
android:tint | The tinting color for the image. |
android:tintMode | Blending mode used to apply the image tint. |
2、Switch
android:showText | Whether to draw on/off text. |
android:splitTrack | Whether to split the track and leave a gap for the thumb drawable. |
android:switchMinWidth | Minimum width for the switch component. |
android:switchPadding | Minimum space between the switch and caption text. |
android:switchTextAppearance | TextAppearance style for text displayed on the switch thumb. |
android:textOff | Text to use when the switch is in the unchecked/"off" state. |
android:textOn | Text to use when the switch is in the checked/"on" state. |
android:textStyle | Style (normal, bold, italic, bold|italic) for the text. |
android:thumb | Drawable to use as the "thumb" that switches back and forth. |
android:thumbTextPadding | Amount of padding on either side of text within the switch thumb. |
android:thumbTint | Tint to apply to the thumb. |
android:thumbTintMode | Blending mode used to apply the thumb tint. |
android:track | Drawable to use as the "track" that the switch thumb slides within. |
android:trackTint | Tint to apply to the track. |
android:trackTintMode | Blending mode used to apply the track tint. |
android:typeface | Typeface (normal, sans, serif, monospace) for the text. |
3、DatePicker
| The text color list of the calendar. |
android:calendarViewShown | Whether the calendar view is shown. |
android:datePickerMode | Defines the look of the widget. |
android:dayOfWeekBackground | The background color for the header's day of week. |
android:dayOfWeekTextAppearance | The text color for the header's day of week. |
android:endYear | The last year (inclusive), for example "2010". |
android:firstDayOfWeek | The first day of week according to Calendar. |
android:headerBackground | The background for the selected date header. |
android:headerDayOfMonthTextAppearance | The text appearance for the day of month (ex. |
android:headerMonthTextAppearance | The text appearance for the month (ex. |
android:headerYearTextAppearance | The text appearance for the year (ex. |
android:maxDate | The maximal date shown by this calendar view in mm/dd/yyyy format. |
android:minDate | The minimal date shown by this calendar view in mm/dd/yyyy format. |
android:spinnersShown | Whether the spinners are shown. |
android:startYear | The first year (inclusive), for example "1940". |
android:yearListItemTextAppearance | The list year's text appearance in the list. |
android:yearListSelectorColor | The list year's selected circle color in the list. |
五、补充
一般来讲，有什么属性，就有对应的set和get方法；另外对代码中的if语句块作个简单说明：它表示android版本大于等于8.0以上才执行if里的内容