如何將html內容中的內嵌圖像保存/讀取到內部/外部內存

Question

根據這個問題，我使用了一個自定義ImageGatter類來顯示我使用Picasso從TextView中的服務器獲取的圖像

    public class PicassoImageGetter implements Html.ImageGetter {

    private TextView textView = null;
    Context mContext;

    public PicassoImageGetter() {

    }

    public PicassoImageGetter(TextView target, Context context) {
        textView = target;
        mContext = context;
    }

    @Override
    public Drawable getDrawable(String source) {

        BitmapDrawablePlaceHolder drawable = new BitmapDrawablePlaceHolder();
        Picasso.get().load(source).into(drawable);
        return drawable;

    }

    private class BitmapDrawablePlaceHolder extends BitmapDrawable implements com.squareup.picasso.Target {

        protected Drawable drawable;

        @Override
        public void draw(final Canvas canvas) {
            if (drawable != null) {
                drawable.draw(canvas);
            }
        }

        public void setDrawable(Drawable drawable) {
            this.drawable = drawable;
            int width = drawable.getIntrinsicWidth();
            int height = drawable.getIntrinsicHeight();
            drawable.setBounds(0, 0, width, height);
            setBounds(0, 0, width, height);
            if (textView != null) {
                textView.setText(textView.getText());
            }
        }

        @Override
        public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) {
            setDrawable(new BitmapDrawable(mContext.getResources(), bitmap));
        }

        @Override
        public void onBitmapFailed(Exception e, Drawable errorDrawable) {
            setDrawable(errorDrawable);
        }

        @Override
        public void onPrepareLoad(Drawable placeHolderDrawable) {

        }

    }
}

並使用這樣的

imageGetter = new PicassoImageGetter(contentTextView, this);
    Spannable html;
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
        html = (Spannable) Html.fromHtml(content, Html.FROM_HTML_MODE_LEGACY, imageGetter, null);
    } else {
        html = (Spannable) Html.fromHtml(content, imageGetter, null);
    }

    contentTextView.setText(html);

如果沒有連接，我需要將這些圖像捕獲到內部或外部存儲中以顯示它，但我不知道路徑或文件名。

Answer 1

您需要自己實現picasso緩存。 這應該是這樣的：

public class PicassoCache {

    private static Picasso picassoInstance = null;

    private PicassoCache(Context context) {

        Downloader downloader = new OkHttp3Downloader(context, Integer.MAX_VALUE);
        Picasso.Builder builder = new Picasso.Builder(context);
        builder.downloader(downloader);

        picassoInstance = builder.build();
    }

    public static Picasso getPicassoInstance(Context context) {

        if (picassoInstance == null) {

            new PicassoCache(context);
            return picassoInstance;
        }

        return picassoInstance;
    }
}

然后在你的代碼中：

    @Override
    public Drawable getDrawable(String source) {

        BitmapDrawablePlaceHolder drawable = new BitmapDrawablePlaceHolder();
        PicassoCache.getPicassoInstance(getContext()).load(source).into(drawable);
        return drawable;

    }

OkHttp3Downloader將在您的應用程序緩存目錄中安裝映像緩存。 您還可以使用另一個構造函數和您自己提供的目錄public OkHttp3Downloader(final File cacheDir, final long maxSize)

作為替代方案，您可以使用Glide。 這就像畢加索，但也允許你顯示動畫和緩存策略的GIFs恕我直言有點容易。

Glide.with(context)
     .load(source)
     .apply(RequestOptions().diskCacheStrategy(DiskCacheStrategy.ALL))
     .into(drawable)