Android學習：ActionBar活動條
阿新 • • 發佈：2018-03-17
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菜單定義：
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item android:title="@string/font_size"
android:showAsAction="always|withText"
android:icon="@drawable/font">
<menu>
<!-- 定義一組單選菜單項 -->
<group android:checkableBehavior="single">
<!-- 定義多個菜單項 -->
<item
android:id
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<!-- 定義一組單選菜單項目 -->
<group android:checkableBehavior="single">
<!-- 定義三個菜單項 -->
<item
android:id="@+id/red"
android:title="@string/red_title"
android:alphabeticShortcut="r"/>
<item
android:id="@+id/green"
android:title="@string/green_title"
android:alphabeticShortcut="g"/>
<item
android:id="@+id/blue"
android:title="@string/blue_title"
android:alphabeticShortcut="b"/>
</group>
</menu>
界面定義：
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent"> <TextView android:id="@+id/txt" android:layout_width="match_parent" android:layout_height="wrap_content" android:textSize="15pt" android:text="可通過上下文菜單修改背景色" /> </LinearLayout>
字符串資源：
<resources>
<string name="app_name">ActionItemTest</string>
<string name="hello_world">Hello world!</string>
<string name="action_settings">Settings</string>
<string name="red_title">紅色</string>
<string name="blue_title">藍色</string>
<string name="green_title">綠色</string>
<string name="font_size">字體大小</string>
<string name="font_color">字體顏色</string>
<string name="plain_item">普通菜單項</string>
<string name="font_10">10號字體</string>
<string name="font_12">12號字體</string>
<string name="font_14">14號字體</string>
<string name="font_16">16號字體</string>
<string name="font_18">18號字體</string>
</resources>
代碼：
package allegro.actionbartes; import android.graphics.Color; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.ContextMenu; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends AppCompatActivity { private TextView txt; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); txt = (TextView) findViewById(R.id.txt); // 為文本框註冊上下文菜單 registerForContextMenu(txt); } public boolean onCreateOptionsMenu(Menu menu) { MenuInflater inflator = new MenuInflater(this); //裝填R.menu.my_menu對應的菜單，並添加到menu中 inflator.inflate(R.menu.menu_main, menu); return super.onCreateOptionsMenu(menu); } // 創建上下文菜單時觸發該方法 @Override public void onCreateContextMenu(ContextMenu menu, View source, ContextMenu.ContextMenuInfo menuInfo) { MenuInflater inflator = new MenuInflater(this); //裝填R.menu.context對應的菜單，並添加到menu中 inflator.inflate(R.menu.context , menu); menu.setHeaderIcon(R.drawable.tools); menu.setHeaderTitle("請選擇背景色"); } // 上下文菜單中菜單項被單擊時觸發該方法 @Override public boolean onContextItemSelected(MenuItem mi) { // 勾選該菜單項 mi.setChecked(true); // ① switch (mi.getItemId()) { case R.id.red: mi.setChecked(true); txt.setBackgroundColor(Color.RED); break; case R.id.green: mi.setChecked(true); txt.setBackgroundColor(Color.GREEN); break; case R.id.blue: mi.setChecked(true); txt.setBackgroundColor(Color.BLUE); break; } return true; } @Override // 菜單項被單擊後的回調方法 public boolean onOptionsItemSelected(MenuItem mi) { if(mi.isCheckable()) { // 勾選該菜單項 mi.setChecked(true); // ② } //判斷單擊的是哪個菜單項，並有針對性地作出響應 switch (mi.getItemId()) { case R.id.font_10: txt.setTextSize(10 * 2); break; case R.id.font_12: txt.setTextSize(12 * 2); break; case R.id.font_14: txt.setTextSize(14 * 2); break; case R.id.font_16: txt.setTextSize(16 * 2); break; case R.id.font_18: txt.setTextSize(18 * 2); break; case R.id.red_font: txt.setTextColor(Color.RED); mi.setChecked(true); break; case R.id.green_font: txt.setTextColor(Color.GREEN); mi.setChecked(true); break; case R.id.blue_font: txt.setTextColor(Color.BLUE); mi.setChecked(true); break; case R.id.plain_item: Toast toast = Toast.makeText(MainActivity.this , "您單擊了普通菜單項" , Toast.LENGTH_SHORT); toast.show(); break; } return true; } }
Android學習：ActionBar活動條