Android Application Fundamentals.
1 like405 views
This document provides an overview of Android resources, which include strings, layouts, colors, dimensions, images and other assets that are used in Android applications. It discusses the different types of resources and how they are defined using XML files and referenced using unique IDs in Java code. Key resource types covered include strings, colors, dimensions, layouts, drawables and styles/themes. The document also summarizes common Android views and view groups like buttons, pickers, lists and different layout managers like linear, relative and frame layouts.
Android Application Fundamentals.
- 3. Android Resources Compiled and Uncompiled Android Resources • XML files • Raw files
- 4. String Resources • Define strings in one or more XML resource files. • These XML files containing string-resource definitions reside in the /res/values subdirectory. strings.xml <?xml version="1.0" encoding="utf-8"?> <resources> <string name="hello">hello</string> <string name="app_name">hello appname</string> </resources> Android Resources
- 5. Layout Resources • A key resource used in Android UI programming. public class HelloWorldActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); } ... } Android Resources
- 6. Example main.xml Layout File <?xml version="1.0" encoding="utf- 8"?> <LinearLayout xmlns:android="http://schemas.andr oid.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > </LinearLayout> Android Resources
- 8. Color Resources in Java code int mainBackGroundColor = activity.getResources.getColor(R.color.main_back_ground_color); Using Colors in View Definitions <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:textColor="@color/red" android:text="Sample Text to Show Red Color"/> Android Resources
- 9. Dimension Resources You can specify the dimensions in any of the following units: px: Pixels in: Inches mm: Millimeters pt: Points dp: Density-independent pixels based on pixel density per inch sp: Scale-independent pixels (dimensions that allow for user sizing; helpful for use in fonts) Android Resources
- 10. XML Syntax for Defining Dimension Resources <resources> <dimen name="mysize_in_pixels">1px</dimen> <dimen name="mysize_in_dp">5dp</dimen> <dimen name="medium_size">100sp</dimen> </resources> Using Dimension Resources in XML <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:textSize="@dimen/medium_size"/> Android Resources
- 11. Image Resources Using Image Resources in XML <Button android:id="@+id/button1" android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="Dial" android:background="@drawable/sample_image" /> Android Resources
- 12. Android Resources package com.mycompany.android.my-root-package; public final class R { ...other entries depending on your project and application public static final class string { ...other entries depending on your project and application publicstaticfinal int hello=0x7f040000; publicstaticfinal int app_name=0x7f040001; ...other entries depending on your project and application } ...other entries depending on your project and application } • R.java with unique IDs for the two string resources specified. R.java
- 13. Resource Reference Syntax Android resources are identified (or referenced) by their IDs in Java source code. <TextView android:id="@+id/text"> //Success: Creates an id called "text" in the local package's R.java In the syntax "@+id/text", the + sign has a special meaning. It tells Android that the ID text may not already exist Android Resources
- 15. Buttons
- 16. Basic Button <Button android:id="@+id/button1" android:text="@string/basicBtnLabel" android:layout_width="fill_parent" android:layout_height="wrap_content" /> …………………… ImageButton <ImageButton android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="myClickHandler" android:src="@drawable/icon" /> …………….. ImageButton imageButton2 = (ImageButton)this.findViewById(R.id.imageButton2); imageButton2.setImageResource(R.drawable.icon); Buttons
- 17. ToggleButton <ToggleButton android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Toggle Button" android:textOn="Stop" android:textOff="Run"/> Button button1 = (Button)this.findViewById(R.id.button1); button1.setOnClickListener(new OnClickListener() { public void onClick(View v) { Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("http://www.androidbook.com")); startActivity(intent); } }); Buttons
- 18. CheckBox <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <CheckBox android:id="@+id/chickenCB" android:text="Chicken" android:checked="true" android:layout_width=“wrap_content" android:layout_height="wrap_content" /> <CheckBox android:id="@+id/fishCB" android:text="Fish" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <CheckBox android:id="@+id/steakCB" android:text="Steak" android:checked="true" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </LinearLayout> CheckBox
- 19. RadioButton RadioButton <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent"> <RadioGroup android:id="@+id/rBtnGrp" android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="vertical" > <RadioButton android:id="@+id/chRBtn" android:text="Chicken" android:layout_width="wrap_content" android:layout_height="wrap_content"/> ……………………….. </RadioGroup> </LinearLayout>
- 21. DatePicker <DatePicker android:id="@+id/datePicker" android:layout_width="wrap_content" android:layout_height="wrap_content" /> ……………………….. DatePicker dp = (DatePicker)this.findViewById(R.id.datePicker); dateDefault.setText("Date defaulted to " + (dp.getMonth() + 1) + "/" + dp.getDayOfMonth() + "/" + dp.getYear()); dp.init(2008, 11, 10, null); TimePicker <TimePicker android:id="@+id/timePicker" android:layout_width="wrap_content" android:layout_height="wrap_content" /> ……………………….. TimePicker tp = (TimePicker)this.findViewById(R.id.timePicker); tp.setIs24HourView(true); tp.setCurrentHour(new Integer(10)); tp.setCurrentMinute(new Integer(10)); Pickers
- 23. ListView <ListView android:id="@+id/list" android:layout_width=" wrap_content " android:layout_height=" wrap_content " android:entries=“@array/mylist” /> List
- 24. Layout Manager Layout Manager Description LinearLayout Organizes its children either horizontally or vertically TableLayout Organizes its children in tabular form RelativeLayout Organizes its children relative to one another or to the parent FrameLayout Allows you to dynamically changethe control(s) in the layout
- 26. Layout Manager RelativeLayout <RelativeLayout …………… > <TextView android:id="@+id/userNameLbl" android:text="Username: “ android:layout_alignParentTop="true" /> <EditText android:id="@+id/userNameText" android:layout_toRightOf="@id/userNameLbl" /> <TextView android:id="@+id/pwdLbl" android:layout_below="@id/userNameText" android:text="Password: " /> <EditText android:id="@+id/pwdText" android:layout_toRightOf="@id/pwdLbl" android:layout_below="@id/userNameText" /> <TextView android:id="@+id/pwdCriteria" android:layout_below="@id/pwdText" android:text="Password Criteria... " /> </RelativeLayout>
- 27. TableLayout <TableLayout ……… > <TableRow> <TextView android:text="First Name:“ android:layout_width="wrap_content" android:layout_height="wrap_content" /> <EditText android:text="Edgar“ android:layout_width="wrap_content" android:layout_height="wrap_content" /> </TableRow> <TableRow> <TextView android:text="Last Name:" android:layout_width="wrap_content" android:layout_height="wrap_content" /> <EditText android:text="Poe" android:layout_width="wrap_content" android:layout_height="wrap_content" /> </TableRow> </TableLayout> Layout Manager
- 29. Styles <?xml version="1.0" encoding="utf-8"?> <resources> <style name=“SpelError"> <item name="android:layout_width">fill_parent</item> <item name="android:layout_height">wrap_content</item> <item name="android:textColor">#FF0000</item> <item name="android:typeface">monospace</item> </style> </resources> ……………….. <TextView android:id="@+id/errorText" style="@style/ SpelError" android:text=“Styling” /> Styles
- 30. Themes If you have some style elements you want applied across an entire activity, or across the whole application, you should use a theme instead. A theme is it’s exactly like a style. To specify a theme for an activity or an application, we would add an attribute to the <activity>or <application>tag in the AndroidManifest.xml. <activity android:theme="@style/MyActivityTheme"> <application android:theme="@style/MyApplicationTheme"> Themes