Interaction between multiple activities in Android Development

I. Basic Knowledge:

1. An Intent object contains a set of information:

1. Component name specifies the Activity to be started

2. What to do with Action

3. Data Transmission

4. Category

5. Extras key-value pairs

6. Flags

2. Basic Intent usage:

[Java] view plaincopyprint? // Generate an Intent object

Intent intent = new Intent ();

Intent. putExtra ("testIntent", "123"); // pass data

Intent. setClass (Activity_02.this, OtherActivity. class); // specifies which Activity to jump to (the second parameter)

// Activity_02.this.startActivity (intent );

StartActivity (intent );

// Generate an Intent object

Intent intent = new Intent ();

Intent. putExtra ("testIntent", "123"); // pass data

Intent. setClass (Activity_02.this, OtherActivity. class); // specifies which Activity to jump to (the second parameter)

// Activity_02.this.startActivity (intent );

StartActivity (intent );

[Java]

// Receives data from Intent.

Intent intent = getIntent ();

String value = intent. getStringExtra ("testIntent"); // receives Intent data

MyTextView = (TextView) findViewById (R. id. myTextView );

// MyTextView. setText (R. string. other );

MyTextView. setText (value );

// Receives data from Intent.

Intent intent = getIntent ();

String value = intent. getStringExtra ("testIntent"); // receives Intent data

MyTextView = (TextView) findViewById (R. id. myTextView );

// MyTextView. setText (R. string. other );

MyTextView. setText (value );

3. Button event registration:

[Java]

Private Button myButton = null;

MyButton = (Button) findViewById (R. id. myButton );

MyButton. setOnClickListener (new MyButtonListener ());

Class MyButtonListener implements OnClickListener {

@ Override

Public void onClick (View v ){

// TODO Auto-generated method stub

// Generate an Intent object

Intent intent = new Intent ();

Intent. putExtra ("testIntent", "123"); // pass data

Intent. setClass (Activity_02.this, OtherActivity. class); // specifies which Activity to jump to (second parameter

Number)

// Activity_02.this.startActivity (intent );

StartActivity (intent );

/*

Uri uri = Uri. parse ("smsto: 0800000123 ");

Intent intent = new Intent (Intent. ACTION_SENDTO, uri );

Intent. putExtra ("sms_body", "The SMS text ");

StartActivity (intent );

*/

}

}

Private Button myButton = null;

MyButton = (Button) findViewById (R. id. myButton );

MyButton. setOnClickListener (new MyButtonListener ());

Class MyButtonListener implements OnClickListener {

@ Override

Public void onClick (View v ){

// TODO Auto-generated method stub

// Generate an Intent object

Intent intent = new Intent ();

Intent. putExtra ("testIntent", "123"); // pass data

Intent. setClass (Activity_02.this, OtherActivity. class); // specifies which Activity to jump to (second parameter

Number)

// Activity_02.this.startActivity (intent );

StartActivity (intent );

/*

Uri uri = Uri. parse ("smsto: 0800000123 ");

Intent intent = new Intent (Intent. ACTION_SENDTO, uri );

Intent. putExtra ("sms_body", "The SMS text ");

StartActivity (intent );

*/

}

}

Ii. Code display:

1. "Activity_02srcyanactivity_02Activity_02.java"

[Java]

Package yan. activity_02;

Import android.net. Uri;

Import android. OS. Bundle;

Import android. app. Activity;

Import android. content. Intent;

Import android. view. Menu;

Import android. view. View;

Import android. view. View. OnClickListener;

Import android. widget. Button;

Public class Activity_02 extends Activity {

Private Button myButton = null;

@ Override

Protected void onCreate (Bundle savedInstanceState ){

Super. onCreate (savedInstanceState );

SetContentView (R. layout. activity_02 );

MyButton = (Button) findViewById (R. id. myButton );

MyButton. setOnClickListener (new MyButtonListener ());

}

Class MyButtonListener implements OnClickListener {

@ Override

Public void onClick (View v ){

// TODO Auto-generated method stub

// Generate an Intent object

Intent intent = new Intent ();

Intent. putExtra ("testIntent", "123 ");

Intent. setClass (Activity_02.this, OtherActivity. class );

// Activity_02.this.startActivity (intent );

StartActivity (intent );

/*

Uri uri = Uri. parse ("smsto: 0800000123 ");

Intent intent = new Intent (Intent. ACTION_SENDTO, uri );

Intent. putExtra ("sms_body", "The SMS text ");

StartActivity (intent );

*/

}

}

}

Package yan. activity_02;

Import android.net. Uri;

Import android. OS. Bundle;

Import android. app. Activity;

Import android. content. Intent;

Import android. view. Menu;

Import android. view. View;

Import android. view. View. OnClickListener;

Import android. widget. Button;

Public class Activity_02 extends Activity {

Private Button myButton = null;

@ Override

Protected void onCreate (Bundle savedInstanceState ){

Super. onCreate (savedInstanceState );

SetContentView (R. layout. activity_02 );

MyButton = (Button) findViewById (R. id. myButton );

MyButton. setOnClickListener (new MyButtonListener ());

}

Class MyButtonListener implements OnClickListener {

@ Override

Public void onClick (View v ){

// TODO Auto-generated method stub

// Generate an Intent object

Intent intent = new Intent ();

Intent. putExtra ("testIntent", "123 ");

Intent. setClass (Activity_02.this, OtherActivity. class );

// Activity_02.this.startActivity (intent );

StartActivity (intent );

/*

Uri uri = Uri. parse ("smsto: 0800000123 ");

Intent intent = new Intent (Intent. ACTION_SENDTO, uri );

Intent. putExtra ("sms_body", "The SMS text ");

StartActivity (intent );

*/

}

}

}

2. "Activity_02srcyanactivity_02OtherActivity.java"

[Java]

Package yan. activity_02;

Import android. app. Activity;

Import android. content. Intent;

Import android. OS. Bundle;

Import android. widget. TextView;

Public class OtherActivity extends Activity {

Private TextView myTextView = null;

@ Override

Protected void onCreate (Bundle savedInstanceState ){

// TODO Auto-generated method stub

Super. onCreate (savedInstanceState );

SetContentView (R. layout. other );

Intent intent = getIntent ();

String value = intent. getStringExtra ("testIntent ");

MyTextView = (TextView) findViewById (R. id. myTextView );

// MyTextView. setText (R. string. other );

MyTextView. setText (value );

}

}

Package yan. activity_02;

Import android. app. Activity;

Import android. content. Intent;

Import android. OS. Bundle;

Import android. widget. TextView;

Public class OtherActivity extends Activity {

Private TextView myTextView = null;

@ Override

Protected void onCreate (Bundle savedInstanceState ){

// TODO Auto-generated method stub

Super. onCreate (savedInstanceState );

SetContentView (R. layout. other );

Intent intent = getIntent ();

String value = intent. getStringExtra ("testIntent ");

MyTextView = (TextView) findViewById (R. id. myTextView );

// MyTextView. setText (R. string. other );

MyTextView. setText (value );

}

}

3. "Activity_02reslayoutactivity_02.xml"

[Java]

Android: orientation = "vertical"

Android: layout_width = "fill_parent"

Android: layout_height = "fill_parent"

>

Android: id = "@ + id/myButton"

Android: layout_width = "fill_parent"

Android: layout_height = "wrap_content"

/>

Android: orientation = "vertical"

Android: layout_width = "fill_parent"

Android: layout_height = "fill_parent"

>

Android: id = "@ + id/myButton"

Android: layout_width = "fill_parent"

Android: layout_height = "wrap_content"

/>

4. "Activity_02reslayoutother.xml"

[Java]

Android: orientation = "vertical"

Android: layout_width = "fill_parent"

Android: layout_height = "fill_parent"

>

Android: id = "@ + id/myTextView"

Android: layout_width = "fill_parent"

Android: layout_height = "wrap_content"

/>

Android: orientation = "vertical"

Android: layout_width = "fill_parent"

Android: layout_height = "fill_parent"

>

Android: id = "@ + id/myTextView"

Android: layout_width = "fill_parent"

Android: layout_height = "wrap_content"

/>

5. "Activity_02resvaluesstrings.xml"

[Java]

Activity_02

Hello world!

Settings

Other string

Activity_02

Hello world!

Settings

Other string

6. "Activity_02AndroidManifest.xml"

[Java] view plaincopyprint?

Package = "yan. activity_02"

Android: versionCode = "1"

Android: versionName = "1.0" type = "codeph" text = "/codeph">

Android: minSdkVersion = "4"

Android: targetSdkVersion = "4"/>

Android: allowBackup = "true"

Android: icon = "@ drawable/ic_launcher"

Android: label = "@ string/app_name"

Android: theme = "@ style/AppTheme">

Android: name = "yan. activity_02.Activity_02"

Android: label = "@ string/app_name">

Android: label = "@ string/other">

Package = "yan. activity_02"

Android: versionCode = "1"

Android: versionName = "1.0" type = "codeph" text = "/codeph">

Android: minSdkVersion = "4"

Android: targetSdkVersion = "4"/>

Android: allowBackup = "true"

Android: icon = "@ drawable/ic_launcher"

Android: label = "@ string/app_name"

Android: theme = "@ style/AppTheme">

Android: name = "yan. activity_02.Activity_02"

Android: label = "@ string/app_name">

Android: label = "@ string/other">

Note the activity declaration in this file:

Android: label = "@ string/other">

Iii. effect display:

Click the Button above --> to jump to another Activity.