54 lines
2.1 KiB
Plaintext
54 lines
2.1 KiB
Plaintext
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package com.novelbook.android.utils;
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import android.content.res.Resources;
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import android.graphics.Bitmap;
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import android.graphics.BitmapFactory;
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public class BitmapUtil {
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public static Bitmap decodeSampledBitmapFromResource(Resources res, int resId,
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int reqWidth, int reqHeight) {
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// First decode with inJustDecodeBounds=true to check dimensions
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final BitmapFactory.Options options = new BitmapFactory.Options();
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options.inJustDecodeBounds = true;
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BitmapFactory.decodeResource(res, resId, options);
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// Calculate inSampleSize
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options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
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// Decode bitmap with inSampleSize set
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options.inJustDecodeBounds = false;
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return BitmapFactory.decodeResource(res, resId, options);
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}
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public static int calculateInSampleSize(
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BitmapFactory.Options options, int reqWidth, int reqHeight) {
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// Raw height and width of image
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final int height = options.outHeight;
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final int width = options.outWidth;
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int inSampleSize = 1;
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if (height > reqHeight || width > reqWidth) {
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/** final int halfHeight = height / 2;
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final int halfWidth = width / 2;
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// Calculate the largest inSampleSize value that is a power of 2 and keeps both
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// height and width larger than the requested height and width.
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while ((halfHeight / inSampleSize) > reqHeight
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&& (halfWidth / inSampleSize) > reqWidth) {
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inSampleSize *= 2;
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} */
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final int heightRatio = Math.round((float) height / (float) reqHeight);
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final int widthRatio = Math.round((float) width / (float) reqWidth);
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// 选择宽和高中最小的比率作为inSampleSize的值，这样可以保证最终图片的宽和高
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// 一定都不会大于等于目标的宽和高。
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inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
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}
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return inSampleSize;
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}
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}
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