Android development: the third day -- two activities

A project created in Android usually has an activity by default. Today, we learn how to create another activity based on this, and pass the value in the past through intent.

/** Key points for creating an activity * 1. an activity is a class, which must inherit from activity * 2. the oncreate Method * 3 needs to be rewritten. every activity must be in androidmainifest. configure in XML file * 4. add necessary controls for the activity **/

First, create a new class named otheractivity and rewrite the oncreate () method ,:

Create an XML layout file. You can copy the content from the activity created by the system and add a textview control to display the values passed by intent:

 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"               android:orientation="vertical"               android:layout_width="fill_parent"               android:layout_height="fill_parent">    <TextView        android:id="@+id/myTextView"        android:layout_width="wrap_content"        android:layout_height="wrap_content"/>        </LinearLayout>

Bind it to the androidmanifest. xml file:

<activity     android:name=".otherActivity"     android:label="@string/other"></activity>

The default activity contains several more lines, as shown below:

<activity            android:name=".MainActivity"            android:label="@string/title_activity_main" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>

Add a button control on the previous activity and add a listener.

<Button         android:id="@+id/myButton"        android:layout_width="fill_parent"        android:layout_height="wrap_content"/>

// Add the button listener class mybuttonlistener implements android. view. view. onclicklistener {public void onclick (view v) {// todo auto-generated method stub // generate an intent object intent = new intent (); // intent can transmit data intent between two activities in two different applications. putextra ("testintent", "123"); intent. setclass (mainactivity. this, otheractivity. class); mainactivity. this. startactivity (intent );}}

Associate the button control with the listener above:

// The Return Value of the following function is view, and view is the parent class of all android controls. Button mybutton = (button) findviewbyid (R. id. mybutton); mybutton. settext ("first button"); mybutton. setonclicklistener (New mybuttonlistener ());

Get and display the intent value in otheractivity:

// Get intent = getintent (); string value = intent. getstringextra ("testintent"); mytextview = (textview) findviewbyid (R. id. mytextview); mytextview. settext (value );

OK!

Work hard every day. Come on!

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Author: PANG Hui

Source: http://www.cnblogs.com/pang123hui/

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