Android实例，美图秀秀透明度拖动，拖动条应用

效果如下：

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.mingrisoft.seekbar.MainActivity">

    <ImageView
        android:id="@+id/image1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:scaleType="fitXY"
        android:src="@drawable/t12"
        />

    <SeekBar
        android:id="@+id/seekbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:max="255"
        android:progress="255"/>

    <ImageView
        android:id="@+id/image2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:scaleType="fitXY"
        android:src="@drawable/tt"
        />

</LinearLayout>

MainActivity.java文件

package com.mingrisoft.seekbar;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.SeekBar;

public class MainActivity extends ActionBarActivity {
    private SeekBar seekbar;
    private ImageView image;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        image= (ImageView) findViewById(R.id.image1);
        seekbar= (SeekBar) findViewById(R.id.seekbar);
        seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
                image.setImageAlpha(i);

            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {

            }
        });

    }
}