Ir al contenido principal

Android - Basic Steps (Fragments) II

Add a Fragment Dinamically

  • The general steps are 
    • While the activity is running can add a fragment to the layout 
    • Get reference to the FragmentManager
    • Begin a FragmentTransaction
    • Add the Fragment 
    • Commit the FragmentTransaction


  • To change the previous application to add fragments dynamically, so:
    • In the MainActivity.java override the onCreate method
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mTitleArray = getResources().getStringArray(R.array.Titles);
mQuoteArray = getResources().getStringArray(R.array.Quotes);
setContentView(R.layout.main);

FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager
.beginTransaction();
fragmentTransaction.add(R.id.title_frame, new TitlesFragment());
fragmentTransaction.add(R.id.quote_frame, mQuoteFragment);
fragmentTransaction.commit();
}

    • In the mail.xml file change the tag <fragment> per FragmentLayout

    <FrameLayout
        android:id="@+id/title_frame"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1" >
    </FrameLayout>

    <FrameLayout
        android:id="@+id/quote_frame"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="2" >
    </FrameLayout>

How to add or remove Fragments

In this case at the beginning only one fragment will appear and after selection will appear the detail. If click back button will appear only one fragment.

  • Override the onCreate method
    • Create listener when push the BackButton
R.id.title_fragment_container - Is the first FrameLayout from main.xml
new TitlesFragment() - Is the class related with the FrameLayout

@Override
protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);
setContentView(R.layout.main);

                FragmentManager  mFragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = mFragmentManager
.beginTransaction();
fragmentTransaction.add(R.id.title_fragment_container,
new TitlesFragment());
fragmentTransaction.commit();

mFragmentManager
.addOnBackStackChangedListener(new FragmentManager.OnBackStackChangedListener() {
public void onBackStackChanged() {
setLayout();
}
});
}

  • setLayout method definition
    • If the mQuoteFragment is not added the width is 0
 Are the FrameLayouts defined in the main.xml. Initialized onCreated method.

mTitleFrameLayout = (FrameLayout) findViewById(R.id.title_fragment_container);

mQuotesFrameLayout = (FrameLayout) findViewById(R.id.quote_fragment_container);

Global variable
private final QuotesFragment mQuoteFragment = new QuotesFragment();


if (!mQuoteFragment.isAdded()) {
mTitleFrameLayout.setLayoutParams(new LinearLayout.LayoutParams(
MATCH_PARENT, MATCH_PARENT));
mQuotesFrameLayout.setLayoutParams(new LinearLayout.LayoutParams(0,
MATCH_PARENT));
} else {
mTitleFrameLayout.setLayoutParams(new LinearLayout.LayoutParams(0,
MATCH_PARENT, 1f));
mQuotesFrameLayout.setLayoutParams(new LinearLayout.LayoutParams(0,
MATCH_PARENT, 2f));
}

  • If do click in the menu option, the detail fragment is added
@Override
public void onListSelection(int index) {
if (!mQuoteFragment.isAdded()) {
FragmentTransaction fragmentTransaction = mFragmentManager
.beginTransaction();
fragmentTransaction.add(R.id.quote_fragment_container,
mQuoteFragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
mFragmentManager.executePendingTransactions();
}
if (mQuoteFragment.getShownIndex() != index) {
mQuoteFragment.showIndex(index);
}
}



Configuration Changes

How to avoid delete the fragment 

  • On the method onCreate, use setRetainInstance method in the Fragment class
    • This method avoid to call the methods onDestroy() and onCreate()

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

setRetainInstance(true);
}

Comentarios

Publicar un comentario

Entradas populares de este blog

Android - Basic Steps (Service)

Service Run in the main thread of the hosting application Android can kill the Service if need the resources Purpose Supporting inter-application method execution Performing background processing Start a Service Call Context.startService(Intent intent)\ To call from a Fragment use getActivity().getApplicationContext().startService( intentService); Executing the service After call startService(...)  In the Service is executed the method onStartCommand(...) If the method returns the constant START_NOT_STICKY then Android will not restart the service automatically if the the process is killedp Foreground To execute the service foreground call the method startForeground() Use this if the user is aware of the process Bind to a Service Call the method Context.bindService( Intent service ServiceConnection con int flags ) Send Toast from the Service On the method onStartCommand receive the message   ...
Publicar un comentario
Leer más

BI - SSIS ( Basics I )

SSIS - Basic Concepts Tasks Bulk Insert Task—Loads data into a table by using the BULK INSERT SQL command. Data Flow Task—This is the most important task that loads and transforms data into an OLE DB Destination. Execute Package Task—Enables you to execute a package from within a package, making your SSIS packages modular. Execute Process Task—Executes a program external to your package, like one to split your extract file into many files before processing the individual files. Execute SQL Task—Executes a SQL statement or stored procedure. File System Task—This task can handle directory operations like creating, renaming, or deleting a directory. It can also manage file operations like moving, copying, or deleting files. FTP Task—Sends or receives files from an FTP site. Script Task—Runs a set of VB.NET or C# coding inside a Visual Studio environment. Send Mail Task—Sends a mail message through SMTP. Analysis Services Processing Task—This task processes a SQL Server A...
Publicar un comentario
Leer más

TOGAF9

Kinds of Architectures Business Architecture / Business Process Architecture    Define the business strategy, governance, organization and key business processes Data Architecture    Describe the structure of an organization logical and physical data assets and data resources Application Architecture    Describe a blueprint for the individual application systems to be deploy, interactions and  their relationships to the core business processes of the organization Technology Architecture    Describe the logical software and hardware capabilities that are required to support the deployment of business data and application services. This includes middle-ware infrastructure, networks, communications, processing standards  Architecture Governance Increase transparency of accountability, and informed delegation of authority Controlled risk management Protection of the existing asset base through maximizing  re-us...
Publicar un comentario
Leer más