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
基于纵横比的规模:
float aspectRatio = yourSelectedImage.getWidth() /
(float) yourSelectedImage.getHeight();
int width = 480;
int height = Math.round(width / aspectRatio);
yourSelectedImage = Bitmap.createScaledBitmap(
yourSelectedImage, width, height, false);
使用高度作为基础而不是宽度更改为:
int height = 480;
int width = Math.round(height * aspectRatio);
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;
}
}
有人问在这种情况下如何保持纵横比:
计算用于缩放的因子，并将其用于两个维度。 假设你想要一个图像的高度是屏幕的20%
int scaleToUse = 20; // this will be our percentage
Bitmap bmp = BitmapFactory.decodeResource(
context.getResources(), R.drawable.mypng);
int sizeY = screenResolution.y * scaleToUse / 100;
int sizeX = bmp.getWidth() * sizeY / bmp.getHeight();
Bitmap scaled = Bitmap.createScaledBitmap(bmp, sizeX, sizeY, false);
为了获得屏幕分辨率，你有这样的解决方案: 以像素为单位获取屏幕尺寸
public static Bitmap resizeBitmapByScale(
Bitmap bitmap, float scale, boolean recycle) {
int width = Math.round(bitmap.getWidth() * scale);
int height = Math.round(bitmap.getHeight() * scale);
if (width == bitmap.getWidth()
&& height == bitmap.getHeight()) return bitmap;
Bitmap target = Bitmap.createBitmap(width, height, getConfig(bitmap));
Canvas canvas = new Canvas(target);
canvas.scale(scale, scale);
Paint paint = new Paint(Paint.FILTER_BITMAP_FLAG | Paint.DITHER_FLAG);
canvas.drawBitmap(bitmap, 0, 0, paint);
if (recycle) bitmap.recycle();
return target;
}
private static Bitmap.Config getConfig(Bitmap bitmap) {
Bitmap.Config config = bitmap.getConfig();
if (config == null) {
config = Bitmap.Config.ARGB_8888;
}
return config;
}
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;
}
