Bitmap的使用(三)

打开相册：

Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);

startActivityForResult(intent, 0);

返回的Intent data是一个图片的uri

用BitmapFactory.decodeStream(getContentResolver().openInputStream(uri), null, param)

package com.example.androidtest;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.net.Uri;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.util.Log;

import java.io.FileNotFoundException;

public class MainActivity extends Activity implements OnClickListener {

ImageView chosenImageView;
Button choosePicture;

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

chosenImageView = (ImageView)findViewById(R.id.ChosenImageView);
choosePicture = (Button)findViewById(R.id.ChoosePictureButton);

choosePicture.setOnClickListener(this);

}

public void onClick(View v)
{
Intent choosePictureIntent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(choosePictureIntent, 0);
}

protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);

if (resultCode == RESULT_OK) {
Uri imageFileUri = data.getData();

try {
BitmapFactory.Options bmpFactoryOptions = new BitmapFactory.Options();
bmpFactoryOptions.inJustDecodeBounds = true;
Bitmap bmp = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri), null, bmpFactoryOptions);
bmpFactoryOptions.inSampleSize = 2;
bmpFactoryOptions.inJustDecodeBounds = false;
bmp = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageFileUri), null, bmpFactoryOptions);
Bitmap alteredBitmap = Bitmap.createBitmap(bmp.getWidth(), bmp.getHeight(), bmp.getConfig());
Canvas canvas = new Canvas(alteredBitmap);
Paint paint = new Paint();
canvas.drawBitmap(bmp, 0, 0, paint);
ImageView alteredImageView = (ImageView)findViewById(R.id.AlteredImageView);
alteredImageView.setImageBitmap(alteredBitmap);
chosenImageView.setImageBitmap(bmp);
} catch (FileNotFoundException e) {
Log.v("ERROR", e.toString());
}
}
}
}


activity_mail.xml:

<?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"
>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Choose Picture" android:id="@+id/ChoosePictureButton"/>

<ImageView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/ChosenImageView"></ImageView>
<ImageView android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/AlteredImageView"></ImageView>
</LinearLayout>