Android Learning: Actionbar activity Bar

Menu definition:

<?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> <!--define a set of single-selection menu items--<group Android:checkablebehavi Or= "single" > <!--define multiple menu items--<Item Android:id= "@+id/font_10"Android:title= "@string/font_10"/> <Item Android:id= "@+id/font_12"Android:title= "@string/font_12"/> <Item Android:id= "@+id/font_14"Android:title= "@string/font_14"/> <Item Android:id= "@+id/font_16"Android:title= "@string/font_16"/> <Item Android:id= "@+id/font_18"Android:title= "@string/font_18"/> </group> </menu> </item> <!--Define a common menu item--&LT ; Item Android:id= "@+id/plain_item"android:showasaction= "Always|withtext"Android:title= "@string/plain_item" > </item> <item android:title= "@string/font_color"android:showasaction= "Always"Android:icon= "@drawable/color" > <menu> <!--define a set of allowed check menu items--<group> <!--define three menu items--<Item Android:id= "@+id/red_font"Android:title= "@string/red_title"/> <Item Android:id= "@+id/green_font"Android:title= "@string/green_title"/> <Item Android:id= "@+id/blue_font"Android:title= "@string/blue_title"/> </group> </menu> </item></menu>

<?xml version= "1.0" encoding= "Utf-8"? ><menu xmlns:android= "Http://schemas.android.com/apk/res/android"        > <!--Define a set of menu items--<group android:checkablebehavior= "single" > <!--define three menu items-- <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>

Interface Definition:

<?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= "Background color can be modified from the context menu"        /></linearlayout>

String resource:

<resources>    <string name= "app_name" >ActionItemTest</string>    <string name= "Hello_ World ">hello world!</string>    <string name=" action_settings ">Settings</string>    < String name= "Red_title" > Red </string>    <string name= "Blue_title" > Blue </string>    < String name= "Green_title" > Green </string>    <string name= "font_size" > Font size </string>    < String name= "Font_color" > Font color </string>    <string name= "Plain_item" > General menu items </string>    <string name= "font_10" >10 font </string>    <string name= "Font_12" >12 number font </string>    <string name= "font_14" >14 font </string>    <string name= "font_16" >16 number font </string>    <string name= "font_18" >18 font </string></resources>

Code:

 Packageallegro.actionbartes;ImportAndroid.graphics.Color;Importandroid.support.v7.app.AppCompatActivity;ImportAndroid.os.Bundle;ImportAndroid.view.ContextMenu;ImportAndroid.view.Menu;ImportAndroid.view.MenuInflater;ImportAndroid.view.MenuItem;ImportAndroid.view.View;ImportAndroid.widget.TextView;ImportAndroid.widget.Toast; Public classMainactivityextendsappcompatactivity {PrivateTextView txt; @Overrideprotected voidonCreate (Bundle savedinstancestate) {Super. OnCreate (savedinstancestate);        Setcontentview (R.layout.activity_main); TXT=(TextView) Findviewbyid (r.id.txt); //Registering a context menu for a text boxregisterforcontextmenu (TXT); }     Public BooleanOncreateoptionsmenu (Menu menu) {menuinflater inflator=NewMenuinflater ( This); //reload the R.menu.my_menu corresponding menu and add it to the menusinflator.inflate (R.menu.menu_main, menu); return Super. Oncreateoptionsmenu (menu); }    //trigger This method when creating a context menu@Override Public voidOncreatecontextmenu (ContextMenu menu, View source, contextmenu.contextmenuinfo me Nuinfo) {Menuinflater inflator=NewMenuinflater ( This); //reload the R.menu.context corresponding menu and add it to the menusinflator.inflate (R.menu.context, menu);        Menu.setheadericon (R.drawable.tools); Menu.setheadertitle ("Please select a background color"); }    //trigger This method when the menu item in the context menu is clicked@Override Public Booleanoncontextitemselected (MenuItem mi) {//tick the menu itemMi.setchecked (true);//①        Switch(Mi.getitemid ()) { Caser.id.red:mi.setchecked (true);                Txt.setbackgroundcolor (color.red);  Break;  Caser.id.green:mi.setchecked (true);                Txt.setbackgroundcolor (Color.green);  Break;  Caser.id.blue:mi.setchecked (true);                Txt.setbackgroundcolor (Color.Blue);  Break; }        return true; } @Override//callback method After menu item is clicked     Public Booleanonoptionsitemselected (MenuItem mi) {if(Mi.ischeckable ()) {//tick the menu itemMi.setchecked (true);//②        }        //determine which menu item is clicked and respond in a targeted manner        Switch(Mi.getitemid ()) { CaseR.id.font_10:txt.settextsize (10 * 2);  Break;  CaseR.id.font_12:txt.settextsize (12 * 2);  Break;  CaseR.id.font_14:txt.settextsize (14 * 2);  Break;  CaseR.id.font_16:txt.settextsize (16 * 2);  Break;  CaseR.id.font_18:txt.settextsize (18 * 2);  Break;  CaseR.id.red_font:txt.settextcolor (color.red); Mi.setchecked (true);  Break;  CaseR.id.green_font:txt.settextcolor (Color.green); Mi.setchecked (true);  Break;  CaseR.id.blue_font:txt.settextcolor (Color.Blue); Mi.setchecked (true);  Break;  Caser.id.plain_item:toast Toast= Toast.maketext (mainactivity. This                        , "You clicked the normal menu item", Toast.length_short);                Toast.show ();  Break; }        return true; }}

Android Learning: Actionbar activity Bar