SeekBar（拖动条）的简单功能和用法

SeekBar（拖动条）的简单功能和用法

布局代码

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"tools:context="${relativePackage}.${activityClass}" ><ImageView android:id="@+id/image"android:layout_width="240dp"android:layout_height="360dp"android:src="@drawable/ic_bangumi_guide"/><SeekBar android:id="@+id/seekbar"android:layout_width="fill_parent"android:layout_height="wrap_content"android:max="250"android:progress="255"/></LinearLayout>

实现代码

package com.test.seekbar;import android.app.Activity;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
//案例：通过拖动滑块来改变图片的透明度
public class MainActivity extends Activity {
    private SeekBar seekbar;private ImageView imageview;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);seekbar = (SeekBar)findViewById(R.id.seekbar);imageview = (ImageView)findViewById(R.id.image);seekbar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {@Overridepublic void onStopTrackingTouch(SeekBar seekBar) {// TODO Auto-generated method stub}@Overridepublic void onStartTrackingTouch(SeekBar seekBar) {// TODO Auto-generated method stub}@Overridepublic void onProgressChanged(SeekBar seekBar, int progress,boolean fromUser) {imageview.setAlpha(progress);}});}
}