Android widget 组件

ScrollView

一个可以下拉滚动条的视图区域

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">

Button

按钮

获取并设置事件及委托

Button button = (Button) findViewById(R.id.button);
        button.setOnClickListener(button_listener);

在点击事件方法里面设置了程序标题

private Button.OnClickListener button_listener = new Button.OnClickListener() {
        public void onClick(View v) {
            setTitle("哎呦,button被点了一下");
        }
    };

在点击事件方法里面跳转到Activity 这个和之前的SetContentView（R.Layout.xxx）不一样，后者是绑定到指定模板。

private Button.OnClickListener text_view_button_listener = new Button.OnClickListener() {
        public void onClick(View v) {
            Intent intent = new Intent();
            intent.setClass(MainActivity.this, ViewTextActivity.class);
            startActivity(intent);
        }
    };

TextView

文本显示和Label类似，下面是实现

<TextView 
    android:id="@+id/text_view"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:textSize="16sp"
    android:textColor="#ffffff"
    android:padding="10dip"
    android:background="#cc0000"
    android:text="这里是TextView，你可以在这里输入需要显示的文字信息.."
    />

java实现修改TextView 的值

TextView text_view = (TextView) findViewById(R.id.text_view);
        CharSequence text_view_old = text_view.getText();
        text_view.setText("修改前是：" + text_view_old
                + "\n修改为:TextView的值也是可以动态修改的.");

在AndroidManifest.xml 里面注册一个Activity

EditText

文本输入框

<EditText android:id="@+id/edit_text"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="这里可以输入文字" />

CheckBox

复选框

<CheckBox android:id="@+id/plain_cb"
     android:text="Plain"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
/>

获得是否选中

plain_cb = (CheckBox) findViewById(R.id.plain_cb);

if (plain_cb.isChecked()) {
                r = r + "," + plain_cb.getText();
            }

RadioGroup

单选框按钮组

<RadioGroup
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:checkedButton="@+id/lunch"
        android:id="@+id/menu">
        <RadioButton
            android:text="breakfast"
            android:id="@+id/breakfast"
            />
        <RadioButton
            android:text="lunch"
            android:id="@id/lunch" />
        <RadioButton
            android:text="dinner"
            android:id="@+id/dinner" />
        <RadioButton
            android:text="all"
            android:id="@+id/all" />
    </RadioGroup>

清除选择

mRadioGroup = (RadioGroup) findViewById(R.id.menu);
       Button clearButton = (Button) findViewById(R.id.clear);
       clearButton.setOnClickListener(this);

public void onClick(View v) {
    mRadioGroup.clearCheck();
}

Spinner

下拉框 //86页

<Spinner  android:id="@+id/spinner_1"
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:drawSelectorOnTop="false"
/>

    private static final String[] mCountries = { "China" ,"Russia", "Germany",
            "Ukraine", "Belarus", "USA" };

    private void find_and_modify_view() {

       //数组填充
        spinner_c = (Spinner) findViewById(R.id.spinner_1);
        allcountries = new ArrayList<String>();
        for (int i = 0; i < mCountries.length; i++) {
            allcountries.add(mCountries[i]);
        }
        aspnCountries = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, allcountries);
        aspnCountries .setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner_c.setAdapter(aspnCountries);
       
        //XML填充
        spinner_2 = (Spinner) findViewById(R.id.spinner_2);
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource( this, R.array.countries, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner_2.setAdapter(adapter);
    }

//遗留问题android.R.layout.simple_spinner_item 在那里可以看到。

AutoCompleteTextView

自动完成文本框

<AutoCompleteTextView android:id="@+id/auto_complete"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"/>

将一个数组赋值给自动完成文本框

   @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.autocomplete);
        setTitle("AutoCompleteTextViewActivity");
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_dropdown_item_1line, COUNTRIES);
        AutoCompleteTextView textView = (AutoCompleteTextView) findViewById(R.id.auto_complete);
        textView.setAdapter(adapter);
    }
  
static final String[] COUNTRIES = new String[] {
    "China" ,"Russia", "Germany",
    "Ukraine", "Belarus", "USA" ,"China1" ,"China12", "Germany",
    "Russia2", "Belarus", "USA"
    };

DatePicker

日期选择控件

<DatePicker
    android:id="@+id/date_picker"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

初始化日期选择控件

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setTitle("CheckBoxActivity");
    setContentView(R.layout.date_picker);
    DatePicker dp =  (DatePicker)this.findViewById(R.id.date_picker);
    dp.init(2009, 5, 17, null);
}

TimePicker

时间控件

<TimePicker
android:id="@+id/time_picker"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>

后台设置24小时视图

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setTitle("TimePickerActivity");
    setContentView(R.layout.time_picker);
    TimePicker tp =  (TimePicker)this.findViewById(R.id.time_picker);
    tp.setIs24HourView(true);   
}

ProgressBar

圆形进度条
<ProgressBar
   android:id="@+id/progress_bar"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"/>

水平进度条     
<ProgressBar android:id="@+id/progress_horizontal"
        style="?android:attr/progressBarStyleHorizontal"
        android:layout_width="200dip"
        android:layout_height="wrap_content"
        android:max="100"
        android:progress="50"
        android:secondaryProgress="75" />
</LinearLayout>

SeekBar

拖动栏目

<SeekBar
android:id="@+id/seek"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:max="100"
android:thumb="@drawable/seeker"
android:progress="50"/>

RatingBar

星评级

<RatingBar android:id="@+id/rating_bar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
ratingBarStyleSmall="true" />

ImageView

图片控件，显示一个图片

<ImageView
  android:id="@+id/imagebutton"
  android:src="@drawable/eoe"  //图片存储在资源文件夹
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"/>

ImageButton

图片按钮
<ImageButton android:id="@+id/imagebuttonaa"
  android:src="@drawable/play"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"/>

ImageSwitcher  和 Gallery

展示图片

<ImageSwitcher
      android:id="@+id/switcher"
             android:layout_width="fill_parent"
             android:layout_height="fill_parent"
             android:layout_alignParentTop="true"
             android:layout_alignParentLeft="true" />
             
<Gallery android:id="@+id/gallery"
      android:background="#55000000"
             android:layout_width="fill_parent"
             android:layout_height="60dp"
             android:layout_alignParentBottom="true"
             android:layout_alignParentLeft="true"
             android:gravity="center_vertical"
             android:spacing="16dp" />

GridView

格子展示控件

<GridView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/grid_view"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:numColumns="auto_fit"
    android:verticalSpacing="10dp"
    android:horizontalSpacing="10dp"
    android:columnWidth="90dp"
    android:stretchMode="columnWidth"
    android:gravity="center"
/>

Tab

选项卡

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setTitle("TabDemoActivity");
    TabHost tabHost = getTabHost();
    LayoutInflater.from(this).inflate(R.layout.tab_demo,
            tabHost.getTabContentView(), true);
    tabHost.addTab(tabHost.newTabSpec("tab1").setIndicator("tab1")
            .setContent(R.id.view1));
    tabHost.addTab(tabHost.newTabSpec("tab3").setIndicator("tab2")
            .setContent(R.id.view2));
    tabHost.addTab(tabHost.newTabSpec("tab3").setIndicator("tab3")
            .setContent(R.id.view3));
}