The application icons that come bundled with Android is
accessible through the android.R.drawable
class. For example, if you want to
display a Share icon on your ImageButton, you simple use the setImageResource() method of the view,
like this:
btnShare =
(ImageButton) findViewById(R.id.btnShare);
btnShare.setImageResource(
android.R.drawable.ic_menu_share);
The following code snippet shows how you can use Reflection to go
through the list of constants defined in the android.R.drawable class and
display each icon:
package net.learn2develop.appicons.appicons;
import android.graphics.Color;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ImageButton;
import android.widget.LinearLayout;
import android.widget.TextView;
import java.lang.reflect.Field;
public class MainActivity extends ActionBarActivity {
@Override
protected void
onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//---display
all the icons defined in
// android.R.drawable---
DisplayDrawables(android.R.drawable.class);
}
//---use reflection
to examine the fields in a class---
public void DisplayDrawables(Class
_class){
LinearLayout
linearLayout = (LinearLayout)
findViewById(R.id.linearLayout);
LinearLayout.LayoutParams lp = new
LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
final Field[]
fields = _class.getDeclaredFields();
for (Field
field : fields) {
final int
drawableId;
try {
drawableId = field.getInt(_class);
ImageButton imageButton = new
ImageButton(this);
imageButton.setImageResource(drawableId);
imageButton.setLayoutParams(lp);
imageButton.setBackgroundColor(
Color.TRANSPARENT);
linearLayout.addView(imageButton);
TextView txtView = new TextView(this);
txtView.setText(field.getName());
imageButton.setLayoutParams(lp);
imageButton.setBackgroundColor(
Color.TRANSPARENT);
linearLayout.addView(txtView);
} catch
(Exception e) {
continue;
}
}
}
In the activity_main.xml,
you use a ScrollView to contain a LinearLayout:
<ScrollView xmlns:android=
"http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/linearLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft=
"@dimen/activity_horizontal_margin"
android:paddingRight=
"@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom=
"@dimen/activity_vertical_margin"
android:orientation="vertical"
tools:context=
"net.learn2develop.appicons.appicons.MainActivity">
</LinearLayout>
</ScrollView>
The following screenshot shows the application icons and their corresponding
names:
