This example show how to load photo using Intent.ACTION_OPEN_DOCUMENT, and scale-down to suitable size, to display in ImageView.
MainActivity.java
package com.blogspot.android_er.androidimage;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
import java.io.FileNotFoundException;
public class MainActivity extends AppCompatActivity {
private static final int RQS_OPEN = 1;
Button buttonOpen;
ImageView imageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buttonOpen = (Button) findViewById(R.id.opendocument);
buttonOpen.setOnClickListener(buttonOpenOnClickListener);
imageView = (ImageView)findViewById(R.id.image);
}
View.OnClickListener buttonOpenOnClickListener =
new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent();
intent.setAction(Intent.ACTION_OPEN_DOCUMENT);
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.setType("image/*");
startActivityForResult(intent, RQS_OPEN);
}
};
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK && requestCode == RQS_OPEN) {
Uri dataUri = data.getData();
int w = imageView.getWidth();
int h = imageView.getHeight();
Toast.makeText(MainActivity.this,
dataUri.toString() + " " +
w + " : " + h,
Toast.LENGTH_LONG).show();
try {
Bitmap bm = loadScaledBitmap(dataUri, w, h);
imageView.setImageBitmap(bm);
Toast.makeText(MainActivity.this,
bm.getWidth() + " x " + bm.getHeight(),
Toast.LENGTH_SHORT).show();
} catch (FileNotFoundException e) {
e.printStackTrace();
Toast.makeText(MainActivity.this, e.getMessage(), Toast.LENGTH_LONG).show();
}
}
}
/*
reference:
Load scaled bitmap
http://android-er.blogspot.com/2013/08/load-scaled-bitmap.html
*/
private Bitmap loadScaledBitmap(Uri src, int req_w, int req_h) throws FileNotFoundException {
Bitmap bm = null;
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeStream(getBaseContext().getContentResolver().openInputStream(src),
null, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, req_w, req_h);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
bm = BitmapFactory.decodeStream(
getBaseContext().getContentResolver().openInputStream(src), null, 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) {
// Calculate ratios of height and width to requested height and
// width
final int heightRatio = Math.round((float) height
/ (float) reqHeight);
final int widthRatio = Math.round((float) width / (float) reqWidth);
// Choose the smallest ratio as inSampleSize value, this will
// guarantee
// a final image with both dimensions larger than or equal to the
// requested height and width.
inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
}
return inSampleSize;
}
}
Download the files (Android Studio Format) .