Android UI Tutorial - Android UI in XML with Code








You can build layouts in XML and then use code to populate the dynamic data.

Example

Creating a User Interface in XML with IDs 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical">
    <!-- NAME CONTAINER -->
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/app_name" />

        <TextView
            android:id="@+id/nameValue"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />

    </LinearLayout>
    <!-- ADDRESS CONTAINER -->
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <TextView
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="@string/app_name" />

        <TextView
            android:id="@+id/addrValue"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" />
    </LinearLayout>

</LinearLayout>

The actual strings for these TextViews will come from our strings.xml file in the /res/values folder. The following code shows what our strings.xml file might look like. 

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">java2s.com</string>
    <string name="hello_world">java2s.com</string>
    <string name="action_settings">Settings</string>

</resources>

Referring to Controls in Resources at Runtime 

// ww  w . j av a2 s.  c  o  m
package com.java2s.app;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class MainActivity extends Activity
{
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        TextView nameValue = (TextView)findViewById(R.id.nameValue);
        nameValue.setText("Main");
        TextView addrValue = (TextView)findViewById(R.id.addrValue);
        addrValue.setText("Street");

    }
}
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