在上一章节中虽然可以实现图片的各种效果，但是，想必，你也输入的比较累了吧，其实还有一种更简单的方式，那就是使用滑块来代替手动输入

1. 创建一个 空的 Android 项目 cn.twle.android.ColorMatrixSlider

2. 下载 /static/i/mychild.png 并放到 res/drawable 目录

3. 创建一个一个图片处理的工具类 ImageHelper ，传入 Bitmap，色相，饱和度以及亮度，处理后，返回 处理后的图片

   package cn.twle.android.colormatrixslider;
   
   import android.graphics.Bitmap;
   import android.graphics.Canvas;
   import android.graphics.ColorMatrix;
   import android.graphics.ColorMatrixColorFilter;
   import android.graphics.Paint;
   
   public class ImageHelper {
       /**
        * 该方法用来处理图像，根据色调，饱和度，亮度来调节
        *
        * @param bm:要处理的图像
        * @param hue:色调
        * @param saturation:饱和度
        * @param lum:亮度
        *
        */
       public static Bitmap handleImageEffect(Bitmap bm, float hue, float saturation, float lum) {
           Bitmap bmp = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(), Bitmap.Config.ARGB_8888);
           Canvas canvas = new Canvas(bmp);
           Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
   
           ColorMatrix hueMatrix = new ColorMatrix();
           hueMatrix.setRotate(0, hue);    //0代表R，红色
           hueMatrix.setRotate(1, hue);    //1代表G，绿色
           hueMatrix.setRotate(2, hue);    //2代表B，蓝色
   
           ColorMatrix saturationMatrix = new ColorMatrix();
           saturationMatrix.setSaturation(saturation);
   
           ColorMatrix lumMatrix = new ColorMatrix();
           lumMatrix.setScale(lum, lum, lum, 1);
   
           ColorMatrix imageMatrix = new ColorMatrix();
           imageMatrix.postConcat(hueMatrix);
           imageMatrix.postConcat(saturationMatrix);
           imageMatrix.postConcat(lumMatrix);
   
           paint.setColorFilter(new ColorMatrixColorFilter(imageMatrix));
           canvas.drawBitmap(bm, 0, 0, paint);
   
           return bmp;
       }
   }
   

4. 修改布局文件 activity_main.xml

   <?xml version="1.0" encoding="utf-8" ?>
   <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:orientation="vertical"
       android:padding="5dp">
   
       <ImageView
           android:id="@+id/img_meizi"
           android:layout_width="300dp"
           android:layout_height="300dp"
           android:layout_centerHorizontal="true"
           android:layout_marginBottom="24dp"
           android:layout_marginTop="24dp" />
   
       <TextView
           android:id="@+id/txt_hue"
           android:layout_width="wrap_content"
           android:layout_height="32dp"
           android:layout_below="@id/img_meizi"
           android:gravity="center"
           android:text="色调    :"
           android:textSize="18sp" />
   
       <SeekBar
           android:id="@+id/sb_hue"
           android:layout_width="match_parent"
           android:layout_height="32dp"
           android:layout_below="@id/img_meizi"
           android:layout_toRightOf="@id/txt_hue" />
   
       <TextView
           android:id="@+id/txt_saturation"
           android:layout_width="wrap_content"
           android:layout_height="32dp"
           android:layout_below="@id/txt_hue"
           android:gravity="center"
           android:text="饱和度:"
           android:textSize="18sp" />
   
       <SeekBar
           android:id="@+id/sb_saturation"
           android:layout_width="match_parent"
           android:layout_height="32dp"
           android:layout_below="@id/sb_hue"
           android:layout_toRightOf="@id/txt_saturation" />
   
       <TextView
           android:id="@+id/txt_lun"
           android:layout_width="wrap_content"
           android:layout_height="32dp"
           android:layout_below="@id/txt_saturation"
           android:gravity="center"
           android:text="亮度    :"
           android:textSize="18sp" />
   
       <SeekBar
           android:id="@+id/sb_lum"
           android:layout_width="match_parent"
           android:layout_height="32dp"
           android:layout_below="@id/sb_saturation"
           android:layout_toRightOf="@id/txt_lun" />
   
   </RelativeLayout>
   

5. 修改 MainActivity.java

   package cn.twle.android.colormatrixslider;
   
   import android.graphics.Bitmap;
   import android.graphics.BitmapFactory;
   import android.support.v7.app.AppCompatActivity;
   import android.os.Bundle;
   import android.widget.ImageView;
   import android.widget.SeekBar;
   
   public class MainActivity extends AppCompatActivity implements SeekBar.OnSeekBarChangeListener{
   
       private ImageView img_meizi;
       private SeekBar sb_hue;
       private SeekBar sb_saturation;
       private SeekBar sb_lum;
       private final static int MAX_VALUE = 255;
       private final static int MID_VALUE = 127;
       private float mHue = 0.0f;
       private float mStauration = 1.0f;
       private float mLum = 1.0f;
       private Bitmap mBitmap;
   
       @Override
       protected void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.activity_main);
           mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.mychild);
           bindViews();
       }
   
       private void bindViews() {
           img_meizi = (ImageView) findViewById(R.id.img_meizi);
           sb_hue = (SeekBar) findViewById(R.id.sb_hue);
           sb_saturation = (SeekBar) findViewById(R.id.sb_saturation);
           sb_lum = (SeekBar) findViewById(R.id.sb_lum);
   
           img_meizi.setImageBitmap(mBitmap);
           sb_hue.setMax(MAX_VALUE);
           sb_hue.setProgress(MID_VALUE);
           sb_saturation.setMax(MAX_VALUE);
           sb_saturation.setProgress(MID_VALUE);
           sb_lum.setMax(MAX_VALUE);
           sb_lum.setProgress(MID_VALUE);
   
           sb_hue.setOnSeekBarChangeListener(this);
           sb_saturation.setOnSeekBarChangeListener(this);
           sb_lum.setOnSeekBarChangeListener(this);
   
       }
   
       @Override
       public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
           switch (seekBar.getId()) {
               case R.id.sb_hue:
                   mHue = (progress - MID_VALUE) * 1.0F / MID_VALUE * 180;
                   break;
               case R.id.sb_saturation:
                   mStauration = progress * 1.0F / MID_VALUE;
                   break;
               case R.id.sb_lum:
                   mLum = progress * 1.0F / MID_VALUE;
                   break;
           }
           img_meizi.setImageBitmap(ImageHelper.handleImageEffect(mBitmap, mHue, mStauration, mLum));
       }
   
       @Override
       public void onStartTrackingTouch(SeekBar seekBar) {}
   
       @Override
       public void onStopTrackingTouch(SeekBar seekBar) {}
   }