学步园

这是一个非常简单的Hello world 应用程序，通过这个应用程序,可以看到如何通过创建XML来布局Android应用程序的GUI.

 1. res/layout/main.xml

 <?xml version="1.0" encoding="utf-8"?><br /> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"<br /> android:orientation="vertical"<br /> android:layout_width="fill_parent"<br /> android:layout_height="fill_parent"<br /> ></p> <p><TextView android:id="@+id/showInstruction"<br /> android:layout_width="fill_parent"<br /> android:layout_height="wrap_content"<br /> android:textStyle="normal"<br /> android:text="@string/instruction"<br /> /></p> <p><EditText android:id="@+id/textarea1" android:layout_width="fill_parent" android:layout_height="wrap_content" android:clickable="true" android:singleLine="true" /><Button android:id="@+id/button1"<br /> android:layout_width="wrap_content"<br /> android:layout_height="wrap_content"<br /> android:text="@string/button1_text"<br /> /></p> <p><Button android:id="@+id/button2"<br /> android:layout_width="wrap_content"<br /> android:layout_height="wrap_content"<br /> android:text="@string/button2_text"<br /> /></p> <p><TextView android:id="@+id/showSavedValue"<br /> android:layout_width="fill_parent"<br /> android:layout_height="wrap_content"<br /> android:textStyle="bold"<br /> /></p> <p></LinearLayout>

2. res/values/strings.xml

<?xml version="1.0" encoding="utf-8"?><br /> <resources><br /> <string name="app_name">TextBox</string><br /> <string name="button1_text">Show Value</string><br /> <string name="instruction">Type some value</string></p> <p><string name="button2_text">abc</string><br /> </resources><br />

3. src/TexBox.java

import android.app.Activity;<br /> import android.os.Bundle;<br /> import android.util.Log;<br /> import android.view.View;<br /> import android.widget.Button;<br /> import android.widget.EditText;<br /> import android.widget.TextView;</p> <p>public class TextBox extends Activity implements View.OnClickListener {</p> <p> private EditText myText;</p> <p> /** Called when the activity is first created. */<br /> @Override<br /> public void onCreate(Bundle icicle) {<br /> super.onCreate(icicle);<br /> setContentView(R.layout.main);</p> <p> Button myButton = (Button) findViewById(R.id.button1);</p> <p> myText = (EditText) findViewById(R.id.textarea1);</p> <p> myButton.setOnClickListener(this);</p> <p> Button button2 = (Button) findViewById(R.id.button2);<br /> button2.setOnClickListener(new View.OnClickListener() {<br /> public void onClick(View v) {<br /> Log.i("Example1", "Clicked Button 2");<br /> }<br /> });</p> <p> }</p> <p> public void onClick(View arg0) {<br /> TextView savedText = (TextView) findViewById(R.id.showSavedValue);<br /> savedText.setText(myText.getText());<br /> savedText.setTextSize(24);<br /> }</p> <p>}