如何在2个活动之间传递位图数组 [英] how to pass Bitmap array between 2 activities

问题描述

我已经尝试将位图数组传递给另一个Activity了一个星期，但我还是做不到

I have been trying to pass bitmap array to another Activity for a week but I still can't do it

public class HomePage extends Activity {
private GridView gridView;
public Bitmap[] mBitArray;
public Bitmap[] mBitArray5;


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home_page);
    gridView = (GridView) findViewById(R.id.GridView1);
    mBitArray = new Bitmap[7];
    try
    {
        //these images are stored in the root of "assets"
        mBitArray[0] = getBitmapFromAsset("Gallary/g1p1.jpg");
        mBitArray[1] = getBitmapFromAsset("Gallary/g1p2.jpg");
        mBitArray[2] = getBitmapFromAsset("Gallary/g1p3.jpg");
        mBitArray[3] = getBitmapFromAsset("Gallary/g1p4.jpg");
        mBitArray[4] = getBitmapFromAsset("Gallary/g1p5.jpg");
        mBitArray[5] = getBitmapFromAsset("Gallary/g1p6.jpg");
        mBitArray[6] = getBitmapFromAsset("Gallary/g2p1.jpg");
       mBitArray[7] = getBitmapFromAsset("g2p2.jpg");
        mBitArray[8] = getBitmapFromAsset("hd-01.jpg");
        mBitArray[9] = getBitmapFromAsset("hd-02.jpg");
        mBitArray[10] = getBitmapFromAsset("hd-03.jpg");
        mBitArray[11] = getBitmapFromAsset("hd-04.jpg");
    }
    catch (IOException e)
    {
        e.printStackTrace();
    }

     gridView.setAdapter(new ImageAdapter(this, mBitArray));
      gridView.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> parent, View view, int       position,
                long id) {

            Intent i = new Intent(getApplicationContext(),       FullImageActivity.class);
            i.putExtra("id", position);
            startActivity(i);           
            // TODO Auto-generated method stub

        }
    });
}



public Bitmap getBitmapFromAsset(String strName) throws IOException {
    AssetManager assetManager = getAssets();
    InputStream istr = assetManager.open(strName);
    Bitmap bitmap = BitmapFactory.decodeStream(istr);
    istr.close();
    return bitmap;

}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_home_page, menu);
    return true;
}

}






 public class ImageAdapter extends BaseAdapter {
 private Context mContext;
 private Bitmap[] mImageArray;


public ImageAdapter(Context context, Bitmap[] imgArray)
{
    mContext = context;
    mImageArray = imgArray;
}

public int getCount() {

    return mImageArray.length;
}

public Object getItem(int position) {
    // TODO Auto-generated method stub
    return mImageArray[position];
}


public long getItemId(int position) {
    // TODO Auto-generated method stub
    return position;
}

public View getView(int position, View convertView, ViewGroup parent) {         
    ImageView imageView = new ImageView(mContext);
    imageView.setImageBitmap(mImageArray[position]);
    imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
    imageView.setLayoutParams(new GridView.LayoutParams(153, 150));
    return imageView;
}

public Bitmap getView1(int position) throws IOException {   

    AssetManager am = mContext.getAssets();
    String[] list = am.list("Gallary");
     BufferedInputStream buf = new               BufferedInputStream(am.open(list[position]));

     Bitmap bitmap = BitmapFactory.decodeStream(buf);

 buf.close();
    return bitmap;
}

}

公共类FullImageActivity扩展了Activity {

public class FullImageActivity extends Activity{

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    setContentView(R.layout.fullimage);
    ImageView imageView = (ImageView) findViewById(R.id.full_image_view);
     Intent i = getIntent();
     int position = i.getExtras().getInt("id");


     ImageAdapter imageAdapter = new ImageAdapter(this , null);


    //imageView.setImageBitmap(mBitArray[position]);
    trying to get mBitarray to fullscreenactivity to display a certain picture from the bitmap array

所以我想将MbitArray变量传递给Fullactivity类，我试图通过Intent来实现，但是我可能无法通过构造函数或内部类发送Bitmap数组?

推荐答案

由于位图实现了Parcelable，并且您拥有一个Bitmap数组，您应该能够将其传递出去:

Since Bitmap implements Parcelable, and you have an array of Bitmap, you should be able to pass them off:

Intent i = new Intent(getApplicationContext(), FullImageActivity.class);
i.putExtra("bitmaps", mBitArray);
startActivity(i);  

然后通过 getParcelableArrayExtra()进行检索:

Then retrieve via getParcelableArrayExtra():

Intent i = getIntent();
Bitmap [] bitmaps = (Bitmap[]) i.getParcelableArrayExtra ("bitmaps");

您也可以将String数组中的路径传递给FullImageActivity，然后像在第一个Activity中那样在此处重新制作它们.为了节省代码，如果您选择这种方法，则通过将其静态化来共享该方法是一个好主意，只需记住传递一个Context实例，以便仍然可以使用getAssets():

You can also pass off the paths in a String array to FullImageActivity, then just remake them there, much like you did in your first Activity. To save code, if you choose this approach, making the method shared by making it static would be a good idea, just remember to pass off a Context instance so getAssets() can still be used:

public static Bitmap getBitmapFromAsset(Context context, String strName) throws IOException {
    AssetManager assetManager = context.getAssets();
    InputStream istr = assetManager.open(strName);
    Bitmap bitmap = BitmapFactory.decodeStream(istr);
    istr.close();
    return bitmap;
}

然后从HomePage

mBitArray[0] = getBitmapFromAsset(this,"Gallary/g1p1.jpg");

和来自FullImageActivity

otherBitmapArray[0] = HomePage.getBitmapFromAsset(this, bitmapPaths[0]);

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