商品详情图片模糊问题

老师您好，ui是这样的：

原因是

长图数量不定，索引也不确定。

我有明珠一颗 2020-12-15

源自：架构商品详情模块 1-1 本周目标

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1回答

LovelyChubby 2020-12-15 09:31:28

这是一张图这么大？让ui分开切图，分开给，这样巨长的图加载进来慢不说，glide会做内存压缩就模糊了

你看淘宝就是分开给图

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提问者我有明珠一颗 #1

老师，领导要求我在ui不分开切图的情况下，想办法加载巨长图，使页面看起来不要太模糊。

做法如下：

adapter中，

@Override
    protected void bindData(@NonNull BaseViewHolder holder, String data) {
        ImageView imageView = holder.getViewById(R.id.img_detail);
//        imageView.setImageBitmap(data);
        Glide.with(context).downloadOnly().load(data).into(new CustomTarget<File>() {
            @Override
            public void onResourceReady(@NonNull File resource, @Nullable Transition<? super File> transition) {
                if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P){
                    imageView.setImageBitmap(decodeSampledBitmapFromResource(resource.getPath(),300,300));
                }else{
                    imageView.setImageBitmap(decodeSampledBitmapFromResource(resource.getPath(),500,500));
                }
            }

            @Override
            public void onLoadCleared(@Nullable Drawable placeholder) {

            }
        });
    }

public static Bitmap decodeSampledBitmapFromResource(String pathName, int reqWidth, int reqHeight) {
    // First decode with inJustDecodeBounds=true to check dimensions
    final BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    BitmapFactory.decodeFile(pathName,  options);
    // Calculate inSampleSize
    options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
    // Decode bitmap with inSampleSize set
    options.inJustDecodeBounds = false;
    return BitmapFactory.decodeFile(pathName, options);
}

public static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
    // Raw height and width of image
    final int height = options.outHeight;
    final int width = options.outWidth;
    int inSampleSize = 1;
    if (height > reqHeight || width > reqWidth) {
        final int halfHeight = height / 2;
        final int halfWidth = width / 2;
        // Calculate the largest inSampleSize value that is a power of 2 and keeps both
        // height and width larger than the requested height and width.
        while ((halfHeight / inSampleSize) >= reqHeight
                && (halfWidth / inSampleSize) >= reqWidth) {
            inSampleSize *= 2;
        }
    }
    return inSampleSize;
}

onResourceReady中的处理逻辑不优雅，老师您觉得怎么处理优雅，或者说怎么处理才能更好的解决问题？

2020-12-17 00:51:53

LovelyChubby 回复提问者我有明珠一颗 #2

巨长途使用glide会被压缩模糊，应当使用bitmapRegionDecoder

2020-12-18 10:06:52

提问者我有明珠一颗回复 LovelyChubby #3

package com.phdj.commodity.ui.view;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.util.AttributeSet;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.widget.AppCompatImageView;

public class BigImageView extends AppCompatImageView {

    private String filePath;

    private int bitmapHeight;

    public BigImageView(@NonNull Context context) {
        this(context, null);
    }

    public BigImageView(@NonNull Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public BigImageView(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        if (bitmapHeight != 0 && bitmapHeight > canvas.getMaximumBitmapHeight()) {
            Bitmap bitmap = decodeSampledBitmapFromResource(filePath, canvas.getMaximumBitmapHeight() - 1);
            setImageBitmap(bitmap);
        }
        bitmapHeight = 0;
        super.onDraw(canvas);
    }

    public void setFilePath(String filePath) {
        this.filePath = filePath;
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(filePath, options);
        bitmapHeight = options.outHeight;
        options.inJustDecodeBounds = false;

        setImageBitmap(BitmapFactory.decodeFile(filePath, options));
    }


    public static int calculateInSampleSize(BitmapFactory.Options options, int reqHeight) {
        final int height = options.outHeight;
        final int width = options.outWidth;

        int inSampleSize = 1;
        if (height > width * 2) {
            if (height > reqHeight) {
                while ((height / inSampleSize) >= reqHeight) {
                    inSampleSize *= 2;
                }
            }
        }
        return inSampleSize;
    }

    public static Bitmap decodeSampledBitmapFromResource(String pathName, int reqHeight) {
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(pathName, options);
        options.inSampleSize = calculateInSampleSize(options, reqHeight);
        options.inJustDecodeBounds = false;
        return BitmapFactory.decodeFile(pathName, options);
    }
}