如何在GridView中單擊圖像時顯示圖像的全尺寸？

Question

我在互聯網上看到了這個例子，我需要做的只是添加一個代碼，如何在Gridview中單擊圖片後顯示圖像的全尺寸。任何想法？

public class MainActivity extends Activity { 

    ImageAdapter myImageAdapter; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    GridView gridview = (GridView) findViewById(R.id.gridview); 
    myImageAdapter = new ImageAdapter(this); 
    gridview.setAdapter(myImageAdapter); 

    String ExternalStorageDirectoryPath = Environment 
     .getExternalStorageDirectory() 
     .getAbsolutePath(); 

    String targetPath = ExternalStorageDirectoryPath + "/test/"; 

    Toast.makeText(getApplicationContext(), targetPath, Toast.LENGTH_LONG).show(); 
    File targetDirector = new File(targetPath); 

    File[] files = targetDirector.listFiles(); 
    for (File file : files){ 
    myImageAdapter.add(file.getAbsolutePath()); 
    } 
} 

我認爲這是Adapter類。

public class ImageAdapter extends BaseAdapter { 

private Context mContext; 
ArrayList<String> itemList = new ArrayList<String>(); 

public ImageAdapter(Context c) { 
    mContext = c; 
} 

void add(String path){ 
    itemList.add(path); 
} 

@Override 
public int getCount() { 
return itemList.size(); 
} 

@Override 
public Object getItem(int arg0) { 
// TODO Auto-generated method stub 
return null; 
} 

@Override 
public long getItemId(int position) { 
// TODO Auto-generated method stub 
return 0; 
} 

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 
ImageView imageView; 
    if (convertView == null) { // if it's not recycled, initialize some attributes 
     imageView = new ImageView(mContext); 
     imageView.setLayoutParams(new GridView.LayoutParams(220, 220)); 
     imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); 
     imageView.setPadding(8, 8, 8, 8); 
    } else { 
     imageView = (ImageView) convertView; 
    } 

    Bitmap bm = decodeSampledBitmapFromUri(itemList.get(position), 220, 220); 

    imageView.setImageBitmap(bm); 
    return imageView; 
    } 

    public Bitmap decodeSampledBitmapFromUri(String path, int reqWidth, int reqHeight) { 

    Bitmap bm = null; 
    // First decode with inJustDecodeBounds=true to check dimensions 
    final BitmapFactory.Options options = new BitmapFactory.Options(); 
    options.inJustDecodeBounds = true; 
    BitmapFactory.decodeFile(path, options); 

    // Calculate inSampleSize 
    options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight); 

    // Decode bitmap with inSampleSize set 
    options.inJustDecodeBounds = false; 
    bm = BitmapFactory.decodeFile(path, options); 

    return bm; 
    } 

    public int calculateInSampleSize(

    BitmapFactory.Options options, int reqWidth, int reqHeight) { 
    // Raw height and width of image 
    final int height = options.outHeight; 
    final int width = options.outWidth; 
    int inSampleSize = 1; 

    if (height > reqHeight || width > reqWidth) { 
    if (width > height) { 
    inSampleSize = Math.round((float)height/(float)reqHeight);  
    } else { 
    inSampleSize = Math.round((float)width/(float)reqWidth);  
    } 
    } 

    return inSampleSize;  
    } 

    } 
} 

Answer 1

向您的GridView添加點擊監聽器。從那裏你必須打開第二個活動，顯示全尺寸圖像。

gridview.setOnItemClickListener(new OnItemClickListener() { 
    @Override 
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
     String path = mAdapter.getItem(position); 
     Intent i = new Intent(AndroidTestActivity.this, DetailActivity.class); 
     i.putExtra("path", path); 
     startActivity(i); 
    } 
}); 

或者你使用內置的Android系統功能：
Launching Intent.ACTION_VIEW intent not working on saved image file