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
public Bitmap scaleBitmap(Bitmap mBitmap) {
int ScaleSize = 250;//max Height or width to Scale
int width = mBitmap.getWidth();
int height = mBitmap.getHeight();
float excessSizeRatio = width > height ? width / ScaleSize : height / ScaleSize;
Bitmap bitmap = Bitmap.createBitmap(
mBitmap, 0, 0,(int) (width/excessSizeRatio),(int) (height/excessSizeRatio));
//mBitmap.recycle(); if you are not using mBitmap Obj
return bitmap;
}
其他回答
变化:
profileImage.setImageBitmap(
BitmapFactory.decodeByteArray(imageAsBytes, 0, imageAsBytes.length)
To:
Bitmap b = BitmapFactory.decodeByteArray(imageAsBytes, 0, imageAsBytes.length)
profileImage.setImageBitmap(Bitmap.createScaledBitmap(b, 120, 120, false));
试试这个: 这个函数按比例调整位图的大小。当最后一个参数设置为“X”时，newDimensionXorY被视为s的新宽度，当设置为“Y”时，一个新的高度。
public Bitmap getProportionalBitmap(Bitmap bitmap,
int newDimensionXorY,
String XorY) {
if (bitmap == null) {
return null;
}
float xyRatio = 0;
int newWidth = 0;
int newHeight = 0;
if (XorY.toLowerCase().equals("x")) {
xyRatio = (float) newDimensionXorY / bitmap.getWidth();
newHeight = (int) (bitmap.getHeight() * xyRatio);
bitmap = Bitmap.createScaledBitmap(
bitmap, newDimensionXorY, newHeight, true);
} else if (XorY.toLowerCase().equals("y")) {
xyRatio = (float) newDimensionXorY / bitmap.getHeight();
newWidth = (int) (bitmap.getWidth() * xyRatio);
bitmap = Bitmap.createScaledBitmap(
bitmap, newWidth, newDimensionXorY, true);
}
return bitmap;
}
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;
}
}
* For resize bitmap with width and height ratio.
public static Bitmap getResizedBitmap(Bitmap image, int maxSize) {
int width = image.getWidth();
int height = image.getHeight();
float bitmapRatio = (float) width / (float) height;
if (bitmapRatio > 1) {
width = maxSize;
height = (int) (width / bitmapRatio);
} else {
height = maxSize;
width = (int) (height * bitmapRatio);
}
return Bitmap.createScaledBitmap(image, width, height, true);
}
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。
