android - 覆盖流机器人 :how to get images from a url in the coverflow

Question

嗨，我目前正在测试 android coverflow我试图从 url 中获取图像并将其显示在 coverflow 中我已成功下载图像，但无法放入位图。这是我试过的代码...

package com.example.coverflow;

import java.io.FileInputStream;

import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Shader.TileMode;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.Toast;
import android.widget.ImageView.ScaleType;

import com.example.coverflow.CoverAdapterView.OnItemClickListener;

public class CoverFlowExample extends Activity  {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        CoverFlow coverFlow;
        coverFlow = new CoverFlow(this);

        coverFlow.setAdapter(new ImageAdapter(this));

        ImageAdapter coverImageAdapter = new ImageAdapter(this);

        coverImageAdapter.createReflectedImages();

        coverFlow.setAdapter(coverImageAdapter);

        coverFlow.setSpacing(-15);
        coverFlow.setSelection(8, true);



        setContentView(coverFlow);
        coverFlow.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(CoverAdapterView<?> parent, View view,
                    int position, long id) {
                // TODO Auto-generated method stub
                Log.v("possition ", " this position :"+position );
                Toast.makeText(getApplicationContext(), "position "+position, Toast.LENGTH_SHORT).show();
            }
        });

        // Use this if you want to use XML layout file
        // setContentView(R.layout.main);
        // coverFlow = (CoverFlow) findViewById(R.id.coverflow);

    }

    public class ImageAdapter extends BaseAdapter {
        int mGalleryItemBackground;
        private Context mContext;

        private FileInputStream fis;
        //public Integer[] mImageIds ;

        private Integer[] mImageIds ={1,2,3,4,5};
        /*private Integer[] mImageIds = { R.drawable.kasabian_kasabian,

        R.drawable.killers_day_and_age, R.drawable.garbage_bleed_like_me,
                R.drawable.death_cub_for_cutie_the_photo_album,
                R.drawable.kasabian_kasabian, R.drawable.kasabian_kasabian,
                R.drawable.killers_day_and_age,
                R.drawable.garbage_bleed_like_me,
                R.drawable.massive_attack_collected,
                R.drawable.kasabian_kasabian, R.drawable.kasabian_kasabian,
                R.drawable.kasabian_kasabian

        };*/



        public int getCount2()
        {
            for(int i=0;i<5;i++)
            {
                ImageView imageView = new ImageView(mContext);
                URL url;
                try {
                    url = new URL("http://www.psdgraphics.com/file/retro-tv-icon.jpg");

                Bitmap bmp = BitmapFactory.decodeStream(url.openConnection().getInputStream());

                imageView.setImageBitmap(bmp);
                imageView.setId(i);
                //mImageIds[i]=i;

                } catch (MalformedURLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            return mImageIds.length;
        }

        private ImageView[] mImages;

        public ImageAdapter(Context c) {
            mContext = c;
            mImages = new ImageView[getCount2()];
        }

        public boolean createReflectedImages() {
            // The gap we want between the reflection and the original image
            final int reflectionGap = 4;

            int index = 0;
            for (final int imageId : mImageIds) {
//              Bitmap originalImage = BitmapFactory.decodeResource(
//                      getResources(), imageId);
                URL url;
                Bitmap originalImage= null;
                try {
                url = new URL("http://image10.bizrate-images.com/resize?sq=60&uid=2216744464");

                 originalImage = BitmapFactory.decodeStream(url.openConnection().getInputStream());
                } catch (MalformedURLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                int width = originalImage.getWidth();
                int height = originalImage.getHeight();
                Log.v("width:",""+width+","+height);

                // This will not scale but will flip on the Y axis
                Matrix matrix = new Matrix();
                matrix.preScale(1, -1);

                Log.v("errer her", "aftr originalImage");
                // Create a Bitmap with the flip matrix applied to it.
                // We only want the bottom half of the image
                Bitmap reflectionImage = Bitmap.createBitmap(originalImage, 0,
                        height / 2, width, height / 2, matrix, false);

                // Create a new bitmap with same width but taller to fit
                // reflection
                Bitmap bitmapWithReflection = Bitmap.createBitmap(width,
                        (height + height / 2), Config.ARGB_8888);

                // Create a new Canvas with the bitmap that's big enough for
                // the image plus gap plus reflection
                Canvas canvas = new Canvas(bitmapWithReflection);
                // Draw in the original image
                canvas.drawBitmap(originalImage, 0, 0, null);
                // Draw in the gap
                Paint deafaultPaint = new Paint();
                canvas.drawRect(0, height, width, height + reflectionGap,
                        deafaultPaint);
                // Draw in the reflection
                canvas.drawBitmap(reflectionImage, 0, height + reflectionGap,
                        null);
                Log.v("errer her", "aftr reflectionImage");
                // Create a shader that is a linear gradient that covers the
                // reflection
                Paint paint = new Paint();
                LinearGradient shader = new LinearGradient(0,
                        originalImage.getHeight(), 0,
                        bitmapWithReflection.getHeight() + reflectionGap,
                        0x70ffffff, 0x00ffffff, TileMode.CLAMP);
                // Set the paint to use this shader (linear gradient)
                paint.setShader(shader);
                // Set the Transfer mode to be porter duff and destination in
                paint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
                // Draw a rectangle using the paint with our linear gradient
                canvas.drawRect(0, height, width,
                        bitmapWithReflection.getHeight() + reflectionGap, paint);
                Log.v("errer her", "aftr drawrect");
                ImageView imageView = new ImageView(mContext);
                imageView.setImageBitmap(bitmapWithReflection);
                imageView.setLayoutParams(new CoverFlow.LayoutParams(120, 180));
                imageView.setScaleType(ScaleType.MATRIX);
                mImages[index++] = imageView;

            }
            return true;
        }

        public int getCount() {
            // Log.v("getCoutn(int count)", "" + mImageIds.length);
            return mImageIds.length;
        }

        public Object getItem(int position) {
            // Log.v("getItem(int position)", "" + position);
            return position;
        }

        public long getItemId(int position) {
            // Log.v("getItemID(int position)", "" + position);
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {

            // Use this code if you want to load from resources
            // ImageView i = new ImageView(mContext);
            // i.setImageResource(mImageIds[position]);
            // i.setLayoutParams(new CoverFlow.LayoutParams(130, 130));
            // i.setScaleType(ImageView.ScaleType.MATRIX);
            // return i;

            // Log.v("getview int position mImages", ""+position);
            ImageView imageView = new ImageView(mContext);
            URL url;
            try {
                url = new URL("http://image10.bizrate-images.com/resize?sq=60&uid=2216744464");

            Bitmap bmp = BitmapFactory.decodeStream(url.openConnection().getInputStream());
            imageView.setImageBitmap(bmp);
            imageView.setId(position);

            } catch (MalformedURLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return imageView;
            //return mImages[position];
        }

        /**
         * Returns the size (0.0f to 1.0f) of the views depending on the
         * 'offset' to the center.
         */
        public float getScale(boolean focused, int offset) {
            /* Formula: 1 / (2 ^ offset) */
            Log.v("getScale float ", " " + focused + " " + offset);
            return Math.max(0, 1.0f / (float) Math.pow(2, Math.abs(offset)));
        }

    //  View v=getView(position, convertView, parent);




    }



}

Answer 1

1.创建ImageAdater.java

package com.sample.Adapters;

import java.util.ArrayList;
import android.app.Activity;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.BaseAdapter;
import android.widget.ImageView;
public class ImageAdapter extends BaseAdapter {
     int mGalleryItemBackground;
     private Activity mContext;
     ArrayList<byte[]> imgarray ;
     public ImageAdapter(Activity c,ArrayList<byte[]> array) {
      mContext = c;
      this.imgarray = array ;
     }
     public int getCount() {
         return imgarray.size();
     }

     public Object getItem(int position) {
         return position;
     }
     public long getItemId(int position) {
         return position;
     }
     public View getView( final int position, View convertView, ViewGroup parent) {
         ImageView i = new ImageView(mContext);
         i.setImageBitmap(BitmapFactory.decodeByteArray(imgarray.get(position),  0, imgarray.get(position).length));
         i.setLayoutParams(new com.sample.custom.CoverFlow.LayoutParams(LayoutParams.WRAP_CONTENT-20, LayoutParams.WRAP_CONTENT-20));
         i.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
         BitmapDrawable drawable = (BitmapDrawable) i.getDrawable();
         drawable.setAntiAlias(true);
         return i;
     }
      public float getScale(boolean focused, int offset) { 
        /* Formula: 1 / (2 ^ offset) */ 
          return Math.max(0, 1.0f / (float)Math.pow(2, Math.abs(offset))); 
      } 

 }

2.图片下载方法

public static byte[] getLogoImage(String url){
        try {
            URL imageUrl = new URL(url);
            URLConnection ucon = imageUrl.openConnection();

            InputStream is = ucon.getInputStream();
            BufferedInputStream bis = new BufferedInputStream(is);

            ByteArrayBuffer baf = new ByteArrayBuffer(500);
            int current = 0;
            while ((current = bis.read()) != -1) {
                baf.append((byte) current);
            }

            return baf.toByteArray();
        } catch (Exception e) {
            Log.d("ImageManager", "Error: " + e.toString());
        }
        return null;
    }

3.声明一个ArrayList<byte[]> arraylistgallery = new ArrayList<byte[]>();

这里我假设即将到来的图片总数为 10

for(int i=0 ; i<10 ; i++){
arraylistgallery.add(i,getLogoImage("http://www.psdgraphics.com/file/retro-tv-icon.jpg"));
}

在AsyncTask中下载图片并保存在arraylistgallery ArrayList中并像这样通过

        coverFlow.setVisibility(View.VISIBLE);
        coverFlow.setAdapter(new ImageAdapter(this,arraylistgallery));
        coverFlow.setSpacing(5);
        coverFlow.setSelection(arraylistgallery.size()-1, true);
        coverFlow.setAnimationDuration(1000);