界面设计图
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<SeekBar
android:id="@+id/seekBar1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginTop="51dp" />
<ImageView
android:id="@+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:src="@drawable/a0" />
</LinearLayout>
处理程序的代码
package com.hbsi.csdn.seekbar;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
public class SeekbarActivity extends Activity {
/** Called when the activity is first created. */
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final ImageView iv=(ImageView) findViewById(R.id.imageView1);
SeekBar sb=(SeekBar) findViewById(R.id.seekBar1);
sb.setOnSeekBarChangeListener(new OnSeekBarChangeListener(){
public void onProgressChanged(SeekBar seekBar, int progress,
boolean fromUser) {
iv.setAlpha(progress);
}
public void onStartTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
}
public void onStopTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
}
});
}
}