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。
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
/**
* Kotlin method for Bitmap scaling
* @param bitmap the bitmap to be scaled
* @param pixel the target pixel size
* @param width the width
* @param height the height
* @param max the max(height, width)
* @return the scaled bitmap
*/
fun scaleBitmap(bitmap:Bitmap, pixel:Float, width:Int, height:Int, max:Int):Bitmap {
val scale = px / max
val h = Math.round(scale * height)
val w = Math.round(scale * width)
return Bitmap.createScaledBitmap(bitmap, w, h, true)
}
位图调整基于任何显示大小
public Bitmap bitmapResize(Bitmap imageBitmap) {
Bitmap bitmap = imageBitmap;
float heightbmp = bitmap.getHeight();
float widthbmp = bitmap.getWidth();
// Get Screen width
DisplayMetrics displaymetrics = new DisplayMetrics();
this.getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
float height = displaymetrics.heightPixels / 3;
float width = displaymetrics.widthPixels / 3;
int convertHeight = (int) hight, convertWidth = (int) width;
// higher
if (heightbmp > height) {
convertHeight = (int) height - 20;
bitmap = Bitmap.createScaledBitmap(bitmap, convertWidth,
convertHighet, true);
}
// wider
if (widthbmp > width) {
convertWidth = (int) width - 20;
bitmap = Bitmap.createScaledBitmap(bitmap, convertWidth,
convertHeight, true);
}
return bitmap;
}
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;
}
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。