Java代码:
package com.example.android07_widget; import android.content.Intent; import android.os.Bundle; import android.support.annotation.Nullable; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.widget.ImageView; import android.widget.SeekBar; /** * Created by Administrator on 2017/7/19 0019. */ public class MainActivitythird extends AppCompatActivity { private ImageView iv_mainthird_image; private int currentAlpta=255; private SeekBar sb_mainthird_seekBar; private int n=R.drawable.s10; @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_mainthird); iv_mainthird_image = (ImageView) findViewById(R.id.iv_mainthird_image); sb_mainthird_seekBar = (SeekBar) findViewById(R.id.sb_mainthird_seekBar); //设置默认清晰度 iv_mainthird_image.setImageAlpha(currentAlpta); //设置一张默认默认图片 iv_mainthird_image.setImageResource(n); //设置最大进度值 sb_mainthird_seekBar.setMax(255); //进度条停止的最大值 sb_mainthird_seekBar.setProgress(255); //通过SeekBar进度条,修改图片透明度 sb_mainthird_seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() { @Override public void onProgressChanged(SeekBar seekBar, int i, boolean b) { currentAlpta=i; iv_mainthird_image.setImageAlpha(currentAlpta); } @Override public void onStartTrackingTouch(SeekBar seekBar) { } @Override public void onStopTrackingTouch(SeekBar seekBar) { } }); } }
xml代码:
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent"> <SeekBar android:id="@+id/sb_mainthird_seekBar" android:layout_width="match_parent" android:layout_height="wrap_content" /> <ImageView android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/iv_mainthird_image" /> </LinearLayout>