Android 开源框架 ( 十二 ) 图片加载框架---Fresco

  Fresco是Facebook推出的一款用于Android应用中展示图片的强大图片库。它具有强大的内存管理、渐进式呈现图片、支持加载Gif图和WebP格式等特点。

  相比于其他图片框架要庞大的多,但是对于图片的处理也要比其他框架支持的多。

  Fresco官方中文介绍文档:https://www.fresco-cn.org/

  Fresco GitHub 地址:https://github.com/facebook/fresco

Fresco使用

  1.添加依赖

compile 'com.facebook.fresco:fresco:1.10.0'

  其他相关依赖

compile 'com.facebook.fresco:animated-gif:1.5.0'//加载gif动图需添加此库
compile 'com.facebook.fresco:animated-webp:1.5.0'//加载webp动图需添加此库
compile 'com.facebook.fresco:webpsupport:1.5.0'//支持webp需添加此库
compile 'com.facebook.fresco:imagepipeline-okhttp3:1.5.0'//网络实现层使用okhttp3需添加此库
compile 'jp.wasabeef:fresco-processors:2.1.0@aar'//用于提供fresco的各种图片变换

  2.图片加载布局控件

  必须设置layout_width、layout_height两个属性,否则无法展示。并且注意SimpleDraweeView不支持wrap_content属性。可以参考官方文档:wrap_content的限制 。你必须指定尺寸或者用match_parent来布局。

<com.facebook.drawee.view.SimpleDraweeView
        android:id="@+id/sdv_fresco"
        android:layout_width="130dp"
        android:layout_gravity="center"
        android:layout_height="130dp"
        fresco:placeholderImage="@drawable/atguigu_logo" />

  3.常用属性

  3.1 带进度条的图片

  // 设置样式
    GenericDraweeHierarchyBuilder builder = new GenericDraweeHierarchyBuilder(getResources());
    GenericDraweeHierarchy hierarchy = builder.setProgressBarImage(new ProgressBarDrawable()).build();
    sdvFresco.setHierarchy(hierarchy);
    // 加载图片的地址
    Uri uri = Uri.parse("http://");
    // 加载图片
    sdvFresco.setImageURI(uri);

  3.2 图片的不同裁剪

    CENTER

  GenericDraweeHierarchyBuilder builder = new GenericDraweeHierarchyBuilder(getResources());
    
    //居中,无缩放
    GenericDraweeHierarchy hierarchy = builder.setActualImageScaleType(ScalingUtils.ScaleType.CENTER).build();// 设置样式
    sdvFresco.setHierarchy(hierarchy);
    // 加载图片的地址
    Uri uri = Uri.parse("http://");
    // 加载图片
    sdvFresco.setImageURI(uri);

  CENTER_CROP

//保持宽高比缩小或放大,使得两边都大于或等于显示边界。居中显示
    GenericDraweeHierarchy hierarchy = builder.setActualImageScaleType(ScalingUtils.ScaleType.CENTER_CROP).build();

  FOCUS_CROP

// 同centerCrop, 但居中点不是中点,而是指定的某个点,这里我设置为图片的左上角那点
    PointF point = new PointF(0,0);
    GenericDraweeHierarchy hierarchy = builder.setActualImageScaleType(ScalingUtils.ScaleType.FOCUS_CROP)

  CENTER_INSIDE

//使两边都在显示边界内,居中显示。如果图尺寸大于显示边界,则保持长宽比缩小图片
    GenericDraweeHierarchy hierarchy = builder.setActualImageScaleType(ScalingUtils.ScaleType.CENTER_INSIDE).build();

  FIT_CENTER

//保持宽高比,缩小或者放大,使得图片完全显示在显示边界内。居中显示
    GenericDraweeHierarchy hierarchy = builder.setActualImageScaleType(ScalingUtils.ScaleType.FIT_CENTER).build();

  FIT_START

//保持宽高比,缩小或者放大,使得图片完全显示在显示边界内,不居中,和显示边界左上对齐
    GenericDraweeHierarchy hierarchy = builder.setActualImageScaleType(ScalingUtils.ScaleType.FIT_START).build();

  FIT_END

//保持宽高比,缩小或者放大,使得图片完全显示在显示边界内,不居中,和显示边界右下对齐
    GenericDraweeHierarchy hierarchy = builder.setActualImageScaleType(ScalingUtils.ScaleType.FIT_END).build();

  FIT_XY

//不保持宽高比,填充满显示边界
    GenericDraweeHierarchy hierarchy = builder.setActualImageScaleType(ScalingUtils.ScaleType.FIT_XY).build();

  title mode

//如要使用title mode显示, 需要设置为none
    GenericDraweeHierarchy hierarchy = builder.setActualImageScaleType(null).build();

  3.3 圆形和圆角图片  

  //圆形图片
    parames = RoundingParams.asCircle();
    GenericDraweeHierarchy hierarchy = builder.setRoundingParams(parames).build();
    
    
    //圆角图片
    parames = RoundingParams.fromCornersRadius(50f);
    //parames.setOverlayColor(getResources().getColor(android.R.color.holo_red_light));//覆盖层
    //parames.setBorder(getResources().getColor(android.R.color.holo_blue_light), 5);//边框
    GenericDraweeHierarchy hierarchy = builder.setRoundingParams(parames).build();

  3.4 渐进式展示图片

  // 加载质量配置
    ProgressiveJpegConfig jpegConfig = new ProgressiveJpegConfig() {
        @Override
        public int getNextScanNumberToDecode(int scanNumber) {
            return scanNumber + 2;
        }

        @Override
        public QualityInfo getQualityInfo(int scanNumber) {
            boolean isGoodEnough = (scanNumber >= 5);

            return ImmutableQualityInfo.of(scanNumber, isGoodEnough, false);
        }
    };

    ImagePipelineConfig.newBuilder(this).setProgressiveJpegConfig(jpegConfig).build();
    // 获取图片URL
    Uri uri = Uri.parse("http://");
    // 获取图片请求
    ImageRequest request = ImageRequestBuilder.newBuilderWithSource(uri).setProgressiveRenderingEnabled(true).build();
    DraweeController draweeController = Fresco.newDraweeControllerBuilder()
            .setImageRequest(request)
            .setTapToRetryEnabled(true)
            .setOldController(sdvFresco.getController())//使用oldController可以节省不必要的内存分配
            .build();

    // 设置加载的控制
    sdvFresco.setController(draweeController);

  3.5 GIF动画图片

  Uri uri = Uri.parse("http://");
    DraweeController controller = Fresco.newDraweeControllerBuilder()
            .setUri(uri)
            .setAutoPlayAnimations(true) //是否自动播放
            .setOldController(sdvFresco.getController())
            .build();

    sdvFresco.setController(controller);
    
    // 动画开始
    Animatable animatable = sdvFresco.getController().getAnimatable();
    if(animatable != null && !animatable.isRunning()) {
        animatable.start();
    }
    
    //动画停止
     Animatable animatable = sdvFresco.getController().getAnimatable();
    if(animatable != null && animatable.isRunning()) {
        animatable.stop();
    }

  3.6 多图请求及图片复用

    先显示低分辨率的图,然后是高分辨率的图

  // 图片地址
    Uri lowUri = Uri.parse("http://");
    Uri highUri = Uri.parse("http://");
    // 控制加载图片
    DraweeController controller = Fresco.newDraweeControllerBuilder()
            .setLowResImageRequest(ImageRequest.fromUri(lowUri))
            .setImageRequest(ImageRequest.fromUri(highUri))
            .build();
    // 加载图片
    sdvFresco.setController(controller);
    
    本地缩略图预览
    // 图片地址
    Uri uri = Uri.fromFile(new File(Environment.getExternalStorageDirectory() +"/meinv1.jpg"));
    // 加载图片的请求
    ImageRequest request = ImageRequestBuilder.newBuilderWithSource(uri)
            .setLocalThumbnailPreviewsEnabled(true)
            .build();
    // 控制图片的加载
    DraweeController controller = Fresco.newDraweeControllerBuilder()
            .setImageRequest(request)
            .build();
    // 加载图片
    sdvFresco.setController(controller);
    
    本地图片复用
    //本地图片的复用
    //在请求之前,还会去内存中请求一次图片,没有才会先去本地,最后去网络uri
    //本地准备复用图片的uri  如果本地这个图片不存在,会自动去加载下一个uri
    // 请求加载图片
    Uri uri1 = Uri.fromFile(new File(Environment.getExternalStorageDirectory()+"/meinv.jpg"));
    //图片的网络uri
    Uri uri2 = Uri.parse("http://");
    ImageRequest request1 = ImageRequest.fromUri(uri1);
    ImageRequest request2 = ImageRequest.fromUri(uri2);
    ImageRequest[] requests = {request1, request2};
    // 控制加载图片
    DraweeController controller = Fresco.newDraweeControllerBuilder()
            .setFirstAvailableImageRequests(requests)
            .setOldController(sdvFresco.getController())
            .build();
    // 加载图片
    sdvFresco.setController(controller);

  3.7 图片加载监听

    // 图片加载的控制
     //添加监听事件 .setControllerListener(controllerListener)
    SimpleDraweeView sdvFrescoListener;
     
    DraweeController controller = Fresco.newDraweeControllerBuilder()
            .setOldController(sdvFrescoListener.getController())
            .setImageRequest(request)
            .setControllerListener(controllerListener)
            .build();
private ControllerListener controllerListener = new BaseControllerListener<ImageInfo>(){
        // 加载图片完毕
        @Override
        public void onFinalImageSet(String id, ImageInfo imageInfo, Animatable animatable) {
            super.onFinalImageSet(id, imageInfo, animatable);

            if (imageInfo == null) {
                return;
            }

            // 获取图片的质量
            QualityInfo qualityInfo = imageInfo.getQualityInfo();

            //页面文本打印setText
            tvFrescoListener.setText("Final image received! " +
                    "\nSize: " + imageInfo.getWidth()
                    + "x" + imageInfo.getHeight()
                    + "\nQuality level: " + qualityInfo.getQuality()
                    + "\ngood enough: " + qualityInfo.isOfGoodEnoughQuality()
                    + "\nfull quality: " + qualityInfo.isOfFullQuality());
        }

        // 渐进式加载图片回调
        @Override
        public void onIntermediateImageSet(String id, ImageInfo imageInfo) {
            super.onIntermediateImageSet(id, imageInfo);

            tvFrescoListener2.setText("IntermediateImageSet image receiced");
        }

        // 加载图片失败
        @Override
        public void onFailure(String id, Throwable throwable) {
            super.onFailure(id, throwable);
            
            tvFrescoListener.setText("Error loading" + id);
        }
    }

  3.8 图片修改和旋转

    修内存中改图片大小 setResizeOptions 

   // 图片地址
    Uri uri = Uri.parse("http://");
    // 图片的请求
    ImageRequest request = ImageRequestBuilder.newBuilderWithSource(uri)
            .setResizeOptions(new ResizeOptions(50,50))
            .build();
    // 控制图片的加载
    PipelineDraweeController controller = (PipelineDraweeController) Fresco.newDraweeControllerBuilder()
            .setOldController(sdvFresco.getController())
            .setImageRequest(request)
            .build();
    // 加载图片
    sdvFresco.setController(controller);

    旋转图片 setAutoRotateEnabled

  Uri uri = Uri.parse("http://");
    ImageRequest request = ImageRequestBuilder.newBuilderWithSource(uri)
            .setAutoRotateEnabled(true)
            .build();
    // 控制图片的加载
    DraweeController controller = Fresco.newDraweeControllerBuilder()
            .setOldController(sdvFresco.getController())
            .setImageRequest(request)
            .build();
    // 加载图片
    sdvFresco.setController(controller);

  3.9 修改图片(显示过程同上,主要更改了ImageRequest设置) setPostprocessor

    // 修改图片
    Postprocessor postProcessor = new BasePostprocessor() {
        @Override
        public String getName() {
            return "postProcessor";
        }
        @Override
        public void process(Bitmap bitmap) {
            for (int x = 0; x < bitmap.getWidth(); x += 2) {
                for (int y = 0; y < bitmap.getHeight(); y += 2) {
                    bitmap.setPixel(x, y, Color.RED);
                }
            }
        }
    };

    // 创建图片请求
    ImageRequest request = ImageRequestBuilder.newBuilderWithSource(uri)
            .setPostprocessor(postProcessor)
            .build();

   3.10 动态展示图片(添加SimpleDraweeView到LinearLayout中)

  SimpleDraweeView simpleDraweeView = new SimpleDraweeView(this);
    // 设置宽高比
    simpleDraweeView.setAspectRatio(3.0f);
    
    // 图片的地址
    Uri uri = Uri.parse("http://");
    // 图片的请求
    ImageRequest request = ImageRequestBuilder.newBuilderWithSource(uri)
            .build();
    // 加载图片的控制
    PipelineDraweeController controller = (PipelineDraweeController) Fresco.newDraweeControllerBuilder()
            .setOldController(simpleDraweeView.getController())
            .setImageRequest(request)
            .build();

    // 加载图片
    simpleDraweeView.setController(controller);
    // 添加View到线性布局中
    linearLayout.addView(simpleDraweeView);

 

 

posted @ 2018-08-05 18:43  FreeFunCode  阅读(469)  评论(0编辑  收藏