ImageLoader用法总结

本文主要是介绍ImageLoader用法总结，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

1，配置方法

1，在Gradle中加入依赖

compile files('libs/universal-image-loader-1.9.4.jar')
2，导入jar包 universal-image-loader-1.9.4.jar

3，代码如下

首先在Application中ImageLoader.init(getApplicationContext());
其次
public class ImageLoader {    public static final String TAG = "--ljj-- ImageLoader";    private static DisplayImageOptions options;    private static DisplayImageOptions.Builder builder;    private static Context applicationContext;    private static boolean isShowPicture ;    public static void init(Context applicationContext) {        ImageLoaderConfiguration imageLoaderConfiguration = new ImageLoaderConfiguration.Builder(applicationContext)                .threadPoolSize(Thread.NORM_PRIORITY - 2)//线程池大小                .denyCacheImageMultipleSizesInMemory()//否定高速缓存图像多大小在内存中                .diskCacheFileNameGenerator(new Md5FileNameGenerator())//磁盘缓存文件名生成器MD5                .tasksProcessingOrder(QueueProcessingType.LIFO)//后进先出法                .threadPoolSize(3)                .memoryCache(new WeakMemoryCache())                .memoryCacheSize(2 * 1024 * 1024)                .memoryCacheSizePercentage(13)                .denyCacheImageMultipleSizesInMemory()                .writeDebugLogs()//编写调试日志                .build();//建立        com.nostra13.universalimageloader.core.ImageLoader.getInstance().init(imageLoaderConfiguration);        options = new DisplayImageOptions.Builder()                .showImageOnLoading(R.drawable.image_loading)//加载图片时显示的默认图片                .showImageForEmptyUri(R.drawable.default_error)//显示空URI的图像                .showImageOnFail(R.drawable.default_error)//显示图像失败                .cacheInMemory(true)//是否添加到内存缓存中                .cacheOnDisk(true)//是否添加到硬盘缓存中                .considerExifParams(true)                .bitmapConfig(Bitmap.Config.RGB_565)                .build();        builder = new DisplayImageOptions.Builder()                .showImageOnLoading(R.drawable.image_loading)//加载图片时显示的默认图片                .showImageForEmptyUri(R.drawable.default_error)//显示空URI的图像                .showImageOnFail(R.drawable.default_error)//显示图像失败                .cacheInMemory(true)//是否添加到内存缓存中                .cacheOnDisk(true)//是否添加到硬盘缓存中                .bitmapConfig(Bitmap.Config.RGB_565)                .considerExifParams(true);        ImageLoader.applicationContext = applicationContext;    }    /**     * 普通图片加载     *     * @param imageURL     * @param imageView     */    public static void displayImage(String imageURL, ImageView imageView) {        if(isShowPicture == true){            imageView.setImageResource(R.drawable.default_error);        }else{            com.nostra13.universalimageloader.core.ImageLoader.getInstance().displayImage(urlTransformation(imageURL), imageView, options);        }    }    /**     * 普通图片加载     *     * @param image     图片地址     * @param imageView 控件     */    public static void displayImage(int image, ImageView imageView) {        displayImage("drawable://" + image, imageView);    }    /**     * 圆角图片加载     *     * @param image     图片地址     * @param imageView 控件     */    public static void displayImage(int image, ImageView imageView, int cornerRadiusPixels) {        displayImage("drawable://" + image, imageView, cornerRadiusPixels);    }    /**     * 圆角图片加载     *     * @param imageURL           图片地址     * @param imageView          控件     * @param cornerRadiusPixels 圆角直径（控件宽或高）     */    public static void displayImage(String imageURL, ImageView imageView, int cornerRadiusPixels) {        builder.displayer(new RoundedBitmapDisplayer(Math.round(applicationContext.getResources().getDisplayMetrics().density * cornerRadiusPixels)));//        com.nostra13.universalimageloader.core.ImageLoader.getInstance().displayImage(urlTransformation(imageURL), imageView, builder.build());        if(isShowPicture == true){            imageView.setImageResource(R.drawable.default_error);        }else{            com.nostra13.universalimageloader.core.ImageLoader.getInstance().displayImage(urlTransformation(imageURL), imageView, builder.build());        }    }    /**     * 高斯模糊图片加载     *     * @param image     图片地址     * @param imageView 控件     */    public static void displayBlur(int image, ImageView imageView) {        displayBlur("drawable://" + image, imageView);    }    /**     * 高斯模糊图片加载     *     * @param imageURL  图片地址     * @param imageView 控件     */    public static void displayBlur(String imageURL, ImageView imageView) {//        com.nostra13.universalimageloader.core.ImageLoader.getInstance().loadImage(urlTransformation(imageURL), new BlurImageLoadingListener(imageView));        if(isShowPicture == true){            imageView.setImageResource(R.drawable.default_error);        }else{            com.nostra13.universalimageloader.core.ImageLoader.getInstance().loadImage(urlTransformation(imageURL), new BlurImageLoadingListener(imageView));        }    }    /**     * 水平方向模糊度     */    private static float hRadius = 3;    /**     * 竖直方向模糊度     */    private static float vRadius = 3;    /**     * 模糊迭代度     */    private static int iterations = 2;    public static Bitmap createBitmap(int width, int height, Bitmap.Config config) {        Bitmap bitmap = null;        try {            bitmap = Bitmap.createBitmap(width, height, config);        } catch (OutOfMemoryError e) {            while(bitmap == null) {                System.gc();                System.runFinalization();                bitmap = createBitmap(width, height, config);            }        }        return bitmap;    }    /**     * 高斯模糊     */    public static Bitmap BoxBlurFilter(Bitmap bmp) {        int width = bmp.getWidth();        int height = bmp.getHeight();        int[] inPixels = new int[width * height];        int[] outPixels = new int[width * height];        Bitmap bitmap = createBitmap(width, height, Bitmap.Config.RGB_565);        bmp.getPixels(inPixels, 0, width, 0, 0, width, height);        for (int i = 0; i < iterations; i++) {            blur(inPixels, outPixels, width, height, hRadius);            blur(outPixels, inPixels, height, width, vRadius);        }        blurFractional(inPixels, outPixels, width, height, hRadius);        blurFractional(outPixels, inPixels, height, width, vRadius);        bitmap.setPixels(inPixels, 0, width, 0, 0, width, height);//        Drawable drawable = new BitmapDrawable(bitmap);        return bitmap;    }    private static void blur(int[] in, int[] out, int width, int height, float radius) {        int widthMinus1 = width - 1;        int r = (int) radius;        int tableSize = 2 * r + 1;        int divide[] = new int[256 * tableSize];        for (int i = 0; i < 256 * tableSize; i++)            divide[i] = i / tableSize;        int inIndex = 0;        for (int y = 0; y < height; y++) {            int outIndex = y;            int ta = 0, tr = 0, tg = 0, tb = 0;            for (int i = -r; i <= r; i++) {                int rgb = in[inIndex + clamp(i, 0, width - 1)];                ta += (rgb >> 24) & 0xff;                tr += (rgb >> 16) & 0xff;                tg += (rgb >> 8) & 0xff;                tb += rgb & 0xff;            }            for (int x = 0; x < width; x++) {                out[outIndex] = (divide[ta] << 24) | (divide[tr] << 16) | (divide[tg] << 8) | divide[tb];                int i1 = x + r + 1;                if (i1 > widthMinus1)                    i1 = widthMinus1;                int i2 = x - r;                if (i2 < 0)                    i2 = 0;                int rgb1 = in[inIndex + i1];                int rgb2 = in[inIndex + i2];                ta += ((rgb1 >> 24) & 0xff) - ((rgb2 >> 24) & 0xff);                tr += ((rgb1 & 0xff0000) - (rgb2 & 0xff0000)) >> 16;                tg += ((rgb1 & 0xff00) - (rgb2 & 0xff00)) >> 8;                tb += (rgb1 & 0xff) - (rgb2 & 0xff);                outIndex += height;            }            inIndex += width;        }    }    private static void blurFractional(int[] in, int[] out, int width, int height, float radius) {        radius -= (int) radius;        float f = 1.0f / (1 + 2 * radius);        int inIndex = 0;        for (int y = 0; y < height; y++) {            int outIndex = y;            out[outIndex] = in[0];            outIndex += height;            for (int x = 1; x < width - 1; x++) {                int i = inIndex + x;                int rgb1 = in[i - 1];                int rgb2 = in[i];                int rgb3 = in[i + 1];                int a1 = (rgb1 >> 24) & 0xff;                int r1 = (rgb1 >> 16) & 0xff;                int g1 = (rgb1 >> 8) & 0xff;                int b1 = rgb1 & 0xff;                int a2 = (rgb2 >> 24) & 0xff;                int r2 = (rgb2 >> 16) & 0xff;                int g2 = (rgb2 >> 8) & 0xff;                int b2 = rgb2 & 0xff;                int a3 = (rgb3 >> 24) & 0xff;                int r3 = (rgb3 >> 16) & 0xff;                int g3 = (rgb3 >> 8) & 0xff;                int b3 = rgb3 & 0xff;                a1 = a2 + (int) ((a1 + a3) * radius);                r1 = r2 + (int) ((r1 + r3) * radius);                g1 = g2 + (int) ((g1 + g3) * radius);                b1 = b2 + (int) ((b1 + b3) * radius);                a1 *= f;                r1 *= f;                g1 *= f;                b1 *= f;                out[outIndex] = (a1 << 24) | (r1 << 16) | (g1 << 8) | b1;                outIndex += height;            }            out[outIndex] = in[width - 1];            inIndex += width;        }    }    private static int clamp(int x, int a, int b) {        return (x < a) ? a : (x > b) ? b : x;    }    /**     * 地址转换     * 把相对地址转换成实际地址     *     * @param imageURL     * @return     */    public static String urlTransformation(String imageURL) {        if (imageURL == null || imageURL.trim().isEmpty()) {            return "drawable://" + R.drawable.default_error;        } else if (imageURL.matches(NO_TRANSFORMATION)) {            Log.e(TAG, "不转换 " + imageURL);            return imageURL;        } else {            Log.e(TAG, "转换 " + HttpService.SERVER_ADDRESS + imageURL);            return HttpService.SERVER_ADDRESS + imageURL;        }    }    public static String FILE = "^[Ff][Ii][Ll][Ee]://[\\S]*";    public static String HTTP = "^[Hh][Tt][Tt][Pp]://[\\S]*";    public static String HTTPS = "^[Hh][Tt][Tt][Pp][Ss]://[\\S]*";    public static String CONTENT = "^[Cc][Oo][Nn][Tt][Ee][Nn][Tt]://[\\S]*";    public static String ASSETS = "^[Aa][Ss][Ee][Tt][Ss]://[\\S]*";    public static String DRAWABLE = "^[Dd][Rr][Aa][Ww][Aa][Bb][Ll][Ee]://[\\S]*";    public static String NO_TRANSFORMATION = "(" + FILE + ")|("            + HTTP + ")|("            + HTTPS + ")|("            + CONTENT + ")|("            + ASSETS + ")|("            + FILE + ")|("            + DRAWABLE + ")";    /**     * 把url转成drawable     * 并添加到imageView中     *     * @param url       网络图片地址     * @param imageView 图片控件     */    public static void loadImageFromNetwork(final String url, final ImageView imageView) {        new Thread(new Runnable() {            Drawable loadImageDrawable = loadImageFromNetwork(url);            @Override            public void run() {                // 更新主线程UI资源                imageView.post(new Runnable() {                    @Override                    public void run() {                        imageView.setImageDrawable(loadImageDrawable);                    }                });            }        }).start();  //线程启动    }    /**     * url 转 drawable     *     * @param imageUrl 图片地址     * @return     */    public static Drawable loadImageFromNetwork(String imageUrl) {        Drawable drawable = null;        try {            drawable = Drawable.createFromStream(new URL(imageUrl).openStream(), "image.jpg");        } catch (IOException e) {            Log.d("test", e.getMessage());        }        return drawable;    }    public static boolean isShowPicture() {        return isShowPicture;    }    public static void setIsShowPicture(boolean isShowPicture) {        ImageLoader.isShowPicture = isShowPicture;    }    public static void onDestory(){        com.nostra13.universalimageloader.core.ImageLoader.getInstance().clearMemoryCache();    }}

最后，在需要的地方直接引用就可以
ImageLoader.displayImage(图片地址,图片控件);

2，开发过程中遇到的bug

虽然这个框架有很好的缓存机制，有效的避免了OOM的产生，一般的情况下产生OOM的概率比较小，但是并不能保证OutOfMemoryError永远不发生。在开发过程中稍不留意就可能会遇到内存溢出的问题，根据自己的开发经验，为了避免内存溢出的问题，总结几点注意。
1，在DisplayImageOptions选项中配置bitmapConfig为Bitmap.Config.RGB_565，因为默认是ARGB_8888，使用RGB_565会比使用ARGB_8888少消耗2倍的内存；
2，在DisplayImageOptions选项中设置.imageScaleType(ImageScaleType.IN_SAMPLE_INT)或者imageScaleType(ImageScaleType.EXACTLY)；
3，
protected void onDestroy() {super.onDestroy();ImageLoader.onDestory();
}

这篇关于ImageLoader用法总结的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！