Create a Bitmap/Drawable from file path

问题:

I'm trying to create a Bitmap or Drawable from existing file path.

String path = intent.getStringExtra("FilePath");
BitmapFactory.Options option = new BitmapFactory.Options();
option.inPreferredConfig = Bitmap.Config.ARGB_8888;

mImg.setImageBitmap(BitmapFactory.decodeFile(path));
// mImg.setImageBitmap(BitmapFactory.decodeFile(path, option));
// mImg.setImageDrawable(Drawable.createFromPath(path));
mImg.setVisibility(View.VISIBLE);
mText.setText(path);

But setImageBitmap(), setImageDrawable() doesn't show an image from the path. I've printed path with mText and it looks like : /storage/sdcard0/DCIM/100LGDSC/CAM00001.jpg

What am i doing wrong? Anyone can help me?

回答1:

Create bitmap from file path:

File sd = Environment.getExternalStorageDirectory();
File image = new File(sd+filePath, imageName);
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
Bitmap bitmap = BitmapFactory.decodeFile(image.getAbsolutePath(),bmOptions);
bitmap = Bitmap.createScaledBitmap(bitmap,parent.getWidth(),parent.getHeight(),true);
imageView.setImageBitmap(bitmap);

If you want to scale the bitmap to the parent's height and width then use Bitmap.createScaledBitmap function.

I think you are giving the wrong file path. :) Hope this helps.

回答2:

It works for me:

File imgFile = new  File("/sdcard/Images/test_image.jpg");
if(imgFile.exists()){
    Bitmap myBitmap = BitmapFactory.decodeFile(imgFile.getAbsolutePath());
    //Drawable d = new BitmapDrawable(getResources(), myBitmap);
    ImageView myImage = (ImageView) findViewById(R.id.imageviewTest);
    myImage.setImageBitmap(myBitmap);

}

Edit:

If above hard-coded sdcard directory is not working in your case, you can fetch the sdcard path:

String sdcardPath = Environment.getExternalStorageDirectory().toString();
File imgFile = new  File(sdcardPath);

回答3:

here is a solution:

Bitmap bitmap = BitmapFactory.decodeFile(filePath);

回答4:

Well, using the static Drawable.createFromPath(String pathName) seems a bit more straightforward to me than decoding it yourself... :-)

If your mImg is a simple ImageView, you don't even need it, use mImg.setImageUri(Uri uri) directly.

回答5:

static ArrayList< Drawable>  d;
d = new ArrayList<Drawable>();
for(int i=0;i<MainActivity.FilePathStrings1.size();i++) {
  myDrawable =  Drawable.createFromPath(MainActivity.FilePathStrings1.get(i));
  d.add(myDrawable);
}

回答6:

you can't access your drawables via a path, so if you want a human readable interface with your drawables that you can build programatically.

declare a HashMap somewhere in your class:

private static HashMap<String, Integer> images = null;

//Then initialize it in your constructor:

public myClass() {
  if (images == null) {
    images = new HashMap<String, Integer>();
    images.put("Human1Arm", R.drawable.human_one_arm);
    // for all your images - don't worry, this is really fast and will only happen once
  }
}

Now for access -

String drawable = "wrench";
// fill in this value however you want, but in the end you want Human1Arm etc
// access is fast and easy:
Bitmap wrench = BitmapFactory.decodeResource(getResources(), images.get(drawable));
canvas.drawColor(Color .BLACK);
Log.d("OLOLOLO",Integer.toString(wrench.getHeight()));
canvas.drawBitmap(wrench, left, top, null);