如何利用matrix实现图片倒影效果

@H_673_9@ package com.flection.view; import com.flection.main.R; import android.Annotation.SuppressLint; import android.content.Context; import android.graphics.bitmap; import android.graphics.bitmap.Config; import android.graphics.bitmapFactory; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.LinearGradient; import android.graphics.Matrix; import android.graphics.Paint; import android.graphics.PorterDuffXfermode; import android.graphics.Shader.TileMode; import android.graphics.drawable.bitmapDrawable; import android.util.AttributeSet; import android.view.View; public class FlectionView extends View { Context mContext=null; public FlectionView(Context context) { super(context); } public FlectionView(Context context,AttributeSet attrs) { super(context,attrs); this.mContext=context; } @SuppressLint("DrawAlLOCATIOn") @Override protected void onDraw(Canvas canvas) { //设置背景色 this.setBACkgroundColor(Color.parseColor("#8B8378")); Bitmap oldBitmap = BitmapFactory.decoderesource(mContext.getresources(),R.drawable.dropBox); Bitmap newBitmap = createFlectionBitmap(oldBitmap); canvas.drawBitmap(newBitmap,newBitmap.getWidth(),newBitmap.getHeight(),new Paint()); this.invalidate(); } //获取原图+倒影图的bitmap private Bitmap createFlectionBitmap(Bitmap oldBitmap) { int mWidth = oldBitmap.getWidth(); int mHeight = oldBitmap.getHeight(); //原图和倒影图之间的缝隙 int gap = 2; Matrix matrix = new Matrix(); matrix.preScale(1,-1); Bitmap flection = Bitmap.createBitmap(oldBitmap,mHeight / 2,mWidth,matrix,falsE); Bitmap BACkground = Bitmap.createBitmap(mWidth,mHeight+gap+mHeight/2,Config.ARGB_8888); Canvas canvas = new Canvas(BACkground); Paint p1 = new Paint(); //画出原图 canvas.drawBitmap(oldBitmap,p1); //画出倒影图 canvas.drawBitmap(flection,mHeight+gap,p1); Paint shaderPaint = new Paint(); LinearGradient shader = new LinearGradient(0,mHeight,flection.getHeight(),0x70ffffff,0x00ffffff,TileMode.MIRROR); shaderPaint.setShader(shader); shaderPaint.setXfermode(new PorterDuffXfermode(android.graphics.PorterDuff.Mode.DST_IN)); //画出渐变颜色 canvas.drawRect(0,BACkground.getHeight(),shaderPaint); return BACkground; } }