Android加载长图的多种方案分享

fun loadLargeImage(context: Context, res: String, imageView: SubsamplingScaleImageView) {
            imageView.isQuickScaleEnabled = true
            imageView.maxScale = 15F
            imageView.isZoomEnabled = true
            imageView.setMinimumScaleType(SubsamplingScaleImageView.SCALE_TYPE_CUSTOM)
           
            Glide.with(context).load(res).downloadOnly(object : SimpleTarget<File?>() {
                override fun onResourceReady(resource: File, glideanimation: Transition<in File?>?) {
                    val sWidth = BitmapFactory.decodeFile(resource.absolutePath).width
                    val sHeight = BitmapFactory.decodeFile(resource.absolutePath).height
                    val wm = ContextCompat.getSystemService(context, WindowManager::class.java)
                    val width = wm?.defaultDisplay?.width ?: 0
                    val height = wm?.defaultDisplay?.height ?: 0
                    if (sHeight >= height
                            && sHeight / sWidth >= 3) {
                        imageView.setMinimumScaleType(SubsamplingScaleImageView.SCALE_TYPE_CENTER_CROP)
                        imageView.setImage(ImageSource.uri(Uri.fromFile(resource)), ImageViewState(0.5f, PointF(0f, 0f), 0))
                    } else {
                        imageView.setMinimumScaleType(SubsamplingScaleImageView.SCALE_TYPE_CUSTOM)
                        imageView.setImage(ImageSource.uri(Uri.fromFile(resource)))
                        imageView.setDoubleTapZoomStyle(SubsamplingScaleImageView.ZOOM_FOCUS_CENTER_IMMEDIATE)
                    }
                }
                override fun onLoadFailed(errorDrawable: Drawable?) {
                    super.onLoadFailed(errorDrawable)
                }
            })

        }