Thursday, 17 February 2011

Display Gallery selected image using BitmapFactory

In last exercise "Select Image using Android build-in Gallery", we ask Android build-in Gallery app help to select image, with uri returned. In this exercise, BitmapFactory is used to load the image.

Display Gallery selected image using BitmapFactory

Modify main.xml to add a ImageView to display the returned image
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
<Button
android:id="@+id/loadimage"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Load Image"
/>
<TextView
android:id="@+id/targeturi"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
<ImageView
android:id="@+id/targetimage"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
</LinearLayout>


Modify the code to load image using BitmapFactory.
package com.exercise.AndroidSelectImage;

import java.io.FileNotFoundException;

import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

public class AndroidSelectImage extends Activity {

TextView textTargetUri;
ImageView targetImage;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button buttonLoadImage = (Button)findViewById(R.id.loadimage);
textTargetUri = (TextView)findViewById(R.id.targeturi);
targetImage = (ImageView)findViewById(R.id.targetimage);

buttonLoadImage.setOnClickListener(new Button.OnClickListener(){

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Intent intent = new Intent(Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, 0);
}});
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, data);

if (resultCode == RESULT_OK){
Uri targetUri = data.getData();
textTargetUri.setText(targetUri.toString());
Bitmap bitmap;
try {
bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(targetUri));
targetImage.setImageBitmap(bitmap);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}


Remark@2012-07-14: Recently found that it cannot display large image, such as original photos from camera ~ but I don't know why no error reported!!! Refer to the update post: Scale bitmap Efficiently.

Related:
- Convert URI to real path format
- Read EXIF of JPG file

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