我有一个位图采取的Base64字符串从我的远程数据库，(encodedImage是字符串表示图像与Base64):
profileImage = (ImageView)findViewById(R.id.profileImage);
byte[] imageAsBytes=null;
try {
imageAsBytes = Base64.decode(encodedImage.getBytes());
} catch (IOException e) {e.printStackTrace();}
profileImage.setImageBitmap(
BitmapFactory.decodeByteArray(imageAsBytes, 0, imageAsBytes.length)
);
profileImage是我的ImageView
但在显示在布局的ImageView中之前，我需要调整图像的大小。我得把它调整到120x120。
有人能告诉我调整大小的代码吗?
我发现的例子不能应用于base64字符串获得位图。
当前回答
在API 19中，位图setWidth(int width)和setHeight(int height)已经存在。 http://developer.android.com/reference/android/graphics/Bitmap.html
其他回答
import android.graphics.Matrix
public Bitmap getResizedBitmap(Bitmap bm, int newWidth, int newHeight) {
int width = bm.getWidth();
int height = bm.getHeight();
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
// CREATE A MATRIX FOR THE MANIPULATION
Matrix matrix = new Matrix();
// RESIZE THE BIT MAP
matrix.postScale(scaleWidth, scaleHeight);
// "RECREATE" THE NEW BITMAP
Bitmap resizedBitmap = Bitmap.createBitmap(
bm, 0, 0, width, height, matrix, false);
bm.recycle();
return resizedBitmap;
}
编辑:根据@aveschini的建议，我添加了bm.recycle();为了避免内存泄漏。请注意，如果您将前一个对象用于其他用途，则应相应地处理。
虽然接受的答案是正确的，但它不会通过保持相同的纵横比来调整位图的大小。如果你正在寻找一种方法来调整位图的大小保持相同的纵横比，你可以使用下面的实用函数。该功能的使用细节和解释在此链接中。
public static Bitmap resizeBitmap(Bitmap source, int maxLength) {
try {
if (source.getHeight() >= source.getWidth()) {
int targetHeight = maxLength;
if (source.getHeight() <= targetHeight) { // if image already smaller than the required height
return source;
}
double aspectRatio = (double) source.getWidth() / (double) source.getHeight();
int targetWidth = (int) (targetHeight * aspectRatio);
Bitmap result = Bitmap.createScaledBitmap(source, targetWidth, targetHeight, false);
if (result != source) {
}
return result;
} else {
int targetWidth = maxLength;
if (source.getWidth() <= targetWidth) { // if image already smaller than the required height
return source;
}
double aspectRatio = ((double) source.getHeight()) / ((double) source.getWidth());
int targetHeight = (int) (targetWidth * aspectRatio);
Bitmap result = Bitmap.createScaledBitmap(source, targetWidth, targetHeight, false);
if (result != source) {
}
return result;
}
}
catch (Exception e)
{
return source;
}
}
试试这段代码:
BitmapDrawable drawable = (BitmapDrawable) imgview.getDrawable();
Bitmap bmp = drawable.getBitmap();
Bitmap b = Bitmap.createScaledBitmap(bmp, 120, 120, false);
希望对大家有用。
保持纵横比，
public Bitmap resizeBitmap(Bitmap source, int width,int height) {
if(source.getHeight() == height && source.getWidth() == width) return source;
int maxLength=Math.min(width,height);
try {
source=source.copy(source.getConfig(),true);
if (source.getHeight() <= source.getWidth()) {
if (source.getHeight() <= maxLength) { // if image already smaller than the required height
return source;
}
double aspectRatio = (double) source.getWidth() / (double) source.getHeight();
int targetWidth = (int) (maxLength * aspectRatio);
return Bitmap.createScaledBitmap(source, targetWidth, maxLength, false);
} else {
if (source.getWidth() <= maxLength) { // if image already smaller than the required height
return source;
}
double aspectRatio = ((double) source.getHeight()) / ((double) source.getWidth());
int targetHeight = (int) (maxLength * aspectRatio);
return Bitmap.createScaledBitmap(source, maxLength, targetHeight, false);
}
}
catch (Exception e)
{
return source;
}
}
如果你已经有一个位图，你可以使用下面的代码来调整大小:
Bitmap originalBitmap = <original initialization>;
Bitmap resizedBitmap = Bitmap.createScaledBitmap(
originalBitmap, newWidth, newHeight, false);
