android - 将大量图像加载到钛 ImageView 中

Question

我正在将大量图像加载到钛合金 ImageView 中。问题是在android中我遇到了内存问题。这是我将图像放入 ImageView 的功能。在这个函数中，我正在调整图像的大小。

exports.SetImg = function(img, hightFactor, widthFactor, viewObj, deviceWidth, deviceHeight) {


    if (img != null && img != "") {
        var IMGhight = 0,
            IMGwidth = 0,
            height = 0,
            width = 0;

        var imgTemp = Ti.UI.createImageView({
            image : img
        });
        if (imgTemp != null) {

            if (imgTemp.toBlob().height != null && imgTemp.toBlob().width != null) {


                IMGhight = imgTemp.toBlob().height;
                IMGwidth = imgTemp.toBlob().width;
                height = alturaImg;
                width = larguraImg;

                if (height > deviceHeight * hightFactor) {
                    if (height > deviceHeight * hightFactor) {
                        height = deviceHeight * hightFactor;
                        width = (((deviceHeight * hightFactor) / IMGhight) * IMGwidth);
                    }

                    if (width < deviceWidth * widthFactor) {
                        width = deviceWidth * widthFactor;
                        height = (((deviceWidth * widthFactor) / IMGwidth) * IMGhight);
                    }
                } else if (width > deviceWidth * widthFactor) {
                    if (width > deviceWidth * widthFactor) {
                        width = deviceWidth * widthFactor;
                        height = (((deviceWidth * widthFactor) / IMGwidth) * IMGhight);
                    }

                    if (height < deviceHeight * hightFactor) {
                        height = deviceHeight * hightFactor;
                        width = (((deviceHeight * hightFactor) / IMGhight) * IMGwidth);
                    }
                } else if (height < deviceHeight * hightFactor) {
                    if (height < deviceHeight * hightFactor) {
                        height = deviceHeight * hightFactor;
                        width = (((deviceHeight * hightFactor) / IMGhight) * IMGwidth);
                    }

                    if (width < deviceWidth * widthFactor) {
                        height = deviceWidth * widthFactor;
                        height = (((deviceWidth * widthFactor) / IMGwidth) * IMGhight);
                    }
                } else if (width < deviceWidth * widthFactor) {
                    if (width < deviceWidth * widthFactor) {
                        width = deviceWidth * widthFactor;
                        height = (((deviceWidth * widthFactor) / IMGwidth) * IMGhight);
                    }
                    if (hight < deviceHeight * hightFactor) {
                        hight = deviceHeight * hightFactor;
                        width = (((deviceHeight * hightFactor) / IMGhight) * IMGwidth);
                    }
                }

                var imagem = Ti.UI.createImageView({
                    width : width,
                    height : hight,
                    image : img
                });

                viewObj.add(imagem);
                imagem = null;
                imgTemp = null;
                IMhight = null;
                IMGwidth = null;
                hight = null;
                width = null;
                img = null;
                hightFactor = null;
                widthFactor = null;
                viewObj = null;
                deviceWidth = null;
                deviceHeight = null;
            }
        }
    }
};

我已经为 GC 将所有变量声明为 null，但我仍然遇到内存问题。现在有人如何解决这个问题吗？

问题是我需要为其他东西重用相同的图像，所以我需要它们求助。

Answer 1

将 imgTemp.toBlob() 提取到一个公共(public)变量将对您的内存消耗产生巨大的积极影响。看看幕后发生的事情，您实际上每次调用 toBlob() 时都会多次将图像加载到内存中!我在您的代码中看到 4 次使用加上实际 ImageView 使用，乘以 30 张图像，您已经得到了数百份位图副本。

查看源代码以获得更多证明--

在 TiUIImageView.java 中: https://github.com/appcelerator/titanium_mobile/blob/e6a5f6c086a019dbdf810e225bb13c5c8d9115ac/android/modules/ui/src/java/ti/modules/titanium/ui/widget/TiUIImageView.java#L945

在 TiBlob.java 中: https://github.com/appcelerator/titanium_mobile/blob/415bd6c66dcc55b1a59a59574f3babd3c3a84ede/android/titanium/src/java/org/appcelerator/titanium/TiBlob.java