Android学习-图片缓存组件
图片缓存组件-Universal-Image-Loader
框架的特点
1.多线程下载图片，图片可以来源于网络，文件系统，项目文件夹assets中以及drawable中
2.支持随意的配置ImageLoader,例如线程池，图片下载器，内存缓存策略，硬盘缓存策略
图片显示选项以及其他的一些配置
3.支持图片的内存缓存，文件系统缓存或者SD卡缓存
4.支持图片下载过程的监听
5.根据控件(lmageView)的大小对Bitmap进行裁剪，减少Bitmap占用过多的内存
6.提供在较慢的网络下对图片进行加载
第三方库下载地址：https://github.com/nostra13/Android-Universal-Image-Loader
或者
权限设置
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
MainActivity.java
package com.example.imageloaderdemo;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Shader;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import com.nostra13.universalimageloader.core.DisplayImageOptions;
import com.nostra13.universalimageloader.core.ImageLoader;
import com.nostra13.universalimageloader.core.ImageLoaderConfiguration;
import com.nostra13.universalimageloader.core.assist.FailReason;
import com.nostra13.universalimageloader.core.assist.LoadedFrom;
import com.nostra13.universalimageloader.core.display.BitmapDisplayer;
import com.nostra13.universalimageloader.core.imageaware.ImageAware;
import com.nostra13.universalimageloader.core.listener.ImageLoadingListener;
import com.nostra13.universalimageloader.core.listener.ImageLoadingProgressListener;
public class MainActivity extends AppCompatActivity {
private String url = "http://a.hiphotos.baidu.com/image/pic/item/838ba61ea8d3fd1fc9c7b6853a4e251f94ca5f46.jpg";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ImageView imageView=findViewById(R.id.imageView);
//展示圆的图片
DisplayImageOptions options = new DisplayImageOptions.Builder()
.cacheInMemory(true)
.cacheOnDisk(true)
.displayer(new BitmapDisplayer() {
@Override
public void display(Bitmap bitmap, ImageAware imageAware, LoadedFrom loadedFrom) {
Bitmap bitmap1 = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap1);
BitmapShader shader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
Paint paint = new Paint();
paint.setShader(shader);
canvas.drawCircle(bitmap.getWidth() / 2, bitmap.getHeight() / 2, bitmap.getHeight() / 2, paint);
imageAware.setImageBitmap(bitmap1);
}
}).build();
ImageLoaderConfiguration configuration=new ImageLoaderConfiguration.Builder(this)
.memoryCacheSizePercentage(20)//设置占用内存的百分比
.diskCacheFileCount(100)//磁盘缓存
.diskCacheSize(5 * 1024 * 1024)
// .defaultDisplayImageOptions(DisplayImageOptions.createSimple())
.defaultDisplayImageOptions(options)
.build();
ImageLoader.getInstance().init(configuration);
// ImageLoader.getInstance().init(ImageLoaderConfiguration.createDefault(this));
// ImageLoader.getInstance().displayImage(url,imageView);
//五角星样式
DisplayImageOptions options1 = new DisplayImageOptions.Builder().displayer(
new BitmapDisplayer() {
@Override
public void display(Bitmap bitmap, ImageAware imageAware, LoadedFrom loadedFrom) {
Bitmap bitmap1 = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap1);
BitmapShader shader = new BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
Paint paint = new Paint();
paint.setShader(shader);
Path path = new Path();
path.moveTo(bitmap.getWidth() / 2, 0);
path.lineTo(bitmap.getWidth() / 4, bitmap.getHeight());
path.lineTo(bitmap.getWidth(), bitmap.getHeight() / 3);
path.lineTo(0, bitmap.getHeight() / 3);
path.lineTo(bitmap.getWidth() / 4 * 3, bitmap.getHeight());
canvas.drawPath(path, paint);
imageAware.setImageBitmap(bitmap1);
}
}
).build();
//ImageLoader.getInstance().loadImage();//不展示，仅仅下载一张图片
ImageLoader.getInstance().displayImage(url, imageView, options1);
ImageLoader.getInstance().displayImage(url, imageView, options1, new ImageLoadingListener() {
@Override
public void onLoadingStarted(String imageUri, View view) {
}
@Override
public void onLoadingFailed(String imageUri, View view, FailReason failReason) {
}
@Override
public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
}
@Override
public void onLoadingCancelled(String imageUri, View view) {
}
}, new ImageLoadingProgressListener() {
@Override
public void onProgressUpdate(String imageUri, View view, int current, int total) {
}
});
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_alignParentStart="true" />
</RelativeLayout>