Android 如何从库中调整图像大小？

第一个文件允许用户从图库中选择一张照片，并将其发送给一个将处理该照片的活动。问题是图像对于手机屏幕来说太大了，所以你只能看到图像的上角（就像被放大了一样）

。第二个文件是从intent接收图像数据并将其放置在位图派生的URI中的活动

public class DisplayUndistortedBitmapFromGalleryActivity extends Activity {

    private static final String TAG = "*********DUBFGActivity";
    private Context mContext = this;
    Uri uri;
    private Bitmap mbitmap = null;

    @Override 
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);


         uri = getIntent().getData();
        if(uri != null){
            Log.e(TAG, "uri ok");
        }else {
            Log.e(TAG, "uri not ok");
        }


        try {
              mbitmap = Media.getBitmap(getContentResolver(), uri);
             //setMbitmap(bitmap);
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

我有第三个文件，它是活动的customview。下面的行从位图的活动中检索位图并显示它。有没有办法缩小位图，使其适合屏幕？谢谢

Bitmap bm = ((DisplayUndistortedBitmapFromGalleryActivity)getContext()).getMbitmap();

---

下面是我通常如何调整位图的大小，这是最简单的方法

public class bitmaptest extends Activity {
@Override
public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    LinearLayout linLayout = new LinearLayout(this);

    // load the origial BitMap (500 x 500 px)
    Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(),
           R.drawable.android);

    int width = bitmapOrg.width();
    int height = bitmapOrg.height();
    int newWidth = 200;
    int newHeight = 200;

    // calculate the scale - in this case = 0.4f
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;

    // createa matrix for the manipulation
    Matrix matrix = new Matrix();
    // resize the bit map
    matrix.postScale(scaleWidth, scaleHeight);
    // rotate the Bitmap


    // recreate the new Bitmap
    Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0,
                      width, height, matrix, true);

    // make a Drawable from Bitmap to allow to set the BitMap
    // to the ImageView, ImageButton or what ever
    BitmapDrawable bmd = new BitmapDrawable

编辑：

这是另一个选择

  int targetWidth  = bitmapOrg.getWidth() - 15; //change this to control the size
  int targetHeight = bitmapOrg.getHeight() - 15 ;
  Matrix matrix = new Matrix();
  matrix.postScale(1f, 1f);
  Bitmap resizedBitmap = Bitmap.createBitmap(bmp, 0, 0, targetWidth, targetHeight, matrix, true);

---

下面是我通常如何调整位图的大小，这是最简单的方法

public class bitmaptest extends Activity {
@Override
public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    LinearLayout linLayout = new LinearLayout(this);

    // load the origial BitMap (500 x 500 px)
    Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(),
           R.drawable.android);

    int width = bitmapOrg.width();
    int height = bitmapOrg.height();
    int newWidth = 200;
    int newHeight = 200;

    // calculate the scale - in this case = 0.4f
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;

    // createa matrix for the manipulation
    Matrix matrix = new Matrix();
    // resize the bit map
    matrix.postScale(scaleWidth, scaleHeight);
    // rotate the Bitmap


    // recreate the new Bitmap
    Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0,
                      width, height, matrix, true);

    // make a Drawable from Bitmap to allow to set the BitMap
    // to the ImageView, ImageButton or what ever
    BitmapDrawable bmd = new BitmapDrawable

编辑：

这是另一个选择

  int targetWidth  = bitmapOrg.getWidth() - 15; //change this to control the size
  int targetHeight = bitmapOrg.getHeight() - 15 ;
  Matrix matrix = new Matrix();
  matrix.postScale(1f, 1f);
  Bitmap resizedBitmap = Bitmap.createBitmap(bmp, 0, 0, targetWidth, targetHeight, matrix, true);

---

我使用的不是ImageView，而是customView。我在活动中使用以下代码行来获取位图。mbitmap=Media.getBitmap（getContentResolver（），uri）；我只需要缩小它的大小，但我找不到在位图或bitmapFactory类中使用uri来实现这一点的方法。这里还有更简单的bitmap.createScaledBitmap（）。我使用的不是ImageView，而是customView。我在活动中使用以下代码行来获取位图。mbitmap=Media.getBitmap（getContentResolver（），uri）；我只需要缩小它的大小，但我找不到在位图或bitmapFactory类中使用uri来实现这一点的方法。这里还有更简单的bitmap.createScaledBitmap（）。