Gilde加载网络图片(一)

前两天 一个朋友要在本地加载几M的大图 用于用户滚动查看。按照思路 是压缩后加载显示但是这样会不清晰，

其实gilde用来加载图片 很牛掰 于是了解一下 下面贴上两个工具类：

package com.one.util;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Paint;

import com.bumptech.glide.load.engine.bitmap_recycle.BitmapPool;
import com.bumptech.glide.load.resource.bitmap.BitmapTransformation;

/**
 * gilde显示为圆角图片
 * Created by One on 2016/5/26.
 */
public class GlideCircleTransform extends BitmapTransformation {
    public GlideCircleTransform(Context context) {
        super(context);
    }

    @Override protected Bitmap transform(BitmapPool pool, Bitmap toTransform, int outWidth, int outHeight) {
        return circleCrop(pool, toTransform);
    }

    private static Bitmap circleCrop(BitmapPool pool, Bitmap source) {
        if (source == null) return null;

        int size = Math.min(source.getWidth(), source.getHeight());
        int x = (source.getWidth() - size) / 2;
        int y = (source.getHeight() - size) / 2;

        // TODO this could be acquired from the pool too
        Bitmap squared = Bitmap.createBitmap(source, x, y, size, size);

        Bitmap result = pool.get(size, size, Bitmap.Config.ARGB_8888);
        if (result == null) {
            result = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888);
        }

        Canvas canvas = new Canvas(result);
        Paint paint = new Paint();
        paint.setShader(new BitmapShader(squared, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP));
        paint.setAntiAlias(true);
        float r = size / 2f;
        canvas.drawCircle(r, r, r, paint);
        return result;
    }

    @Override public String getId() {
        return getClass().getName();
    }
}
=======================================================

package com.one.util;

import android.content.Context;
import android.net.Uri;
import android.widget.ImageView;

import com.bumptech.glide.Glide;
import com.one.activity.R;

import java.io.File;

/**
 * Gilde加载图片
 * Created by One on 2016/5/26.
 */
public class ImageLoader {

    /**
     使用 //显示SD卡图片
     File file = new File(imageUrl);
     ImageLoader.getInstance().displayImage(this, file, studentNormal1SubmitDetailIv);

     //显示网络图片
     String url = "";
     ImageLoader.getInstance().displayImage(this,url, studentNormal1SubmitDetailIv);

     //显示为圆形
     ImageLoader.getInstance().displayCricleImage(this,url, studentNormal1SubmitDetailIv);
     */

    public static final String ANDROID_RESOURCE = "android.resource://";
    public static final String FOREWARD_SLASH = "/";



    private static class ImageLoaderHolder {
        private static final ImageLoader INSTANCE = new ImageLoader();

    }

    private ImageLoader() {
    }

    public static final ImageLoader getInstance() {
        return ImageLoaderHolder.INSTANCE;
    }


    //直接加载网络图片
    public void displayImage(Context context, String url, ImageView imageView) {
        Glide.with(context)
                .load(url)
                .centerCrop()
                //.placeholder(R.drawable.two)
                .crossFade()
                .into(imageView);
    }


    //加载SD卡图片
    public void displayImage(Context context, File file, ImageView imageView) {
        Glide.with(context)
                .load(file)
                .centerCrop()
                //.placeholder(R.drawable.two)
                .into(imageView);

    }

    //加载SD卡图片并设置大小
    public void displayImage(Context context, File file, ImageView imageView, int width, int
            height) {
        Glide.with(context)
                .load(file)
                .override(width, height)
                .centerCrop()
                //.placeholder(R.drawable.two)
                .into(imageView);

    }

    //加载网络图片并设置大小
    public void displayImage(Context context, String url, ImageView imageView, int width, int
            height) {
        Glide.with(context)
                .load(url)
                .centerCrop()
                //.placeholder(R.drawable.two)
                .override(width, height)
                .crossFade()
                .into(imageView);
    }

    //加载drawable图片
    public void displayImage(Context context, int resId, ImageView imageView) {
        Glide.with(context)
                .load(resourceIdToUri(context, resId))
                .crossFade()
                //.placeholder(R.drawable.two)
                .into(imageView);
    }

    //加载drawable图片显示为圆形图片
    public void displayCricleImage(Context context, int resId, ImageView imageView) {
        Glide.with(context)
                .load(resourceIdToUri(context, resId))
                .crossFade()
                .placeholder(R.drawable.two)
                .transform(new GlideCircleTransform(context))
                .into(imageView);
    }

    //加载网络图片显示为圆形图片
    public void displayCricleImage(Context context, String url, ImageView imageView) {
        Glide.with(context)
                .load(url)
                .centerCrop()
                .transform(new GlideCircleTransform(context))
                .crossFade()
                //.placeholder(R.drawable.two) 这里要的默认背景图片 要尺寸和加载的大小一下 不然会受影响
                .into(imageView);
    }

    //加载SD卡图片显示为圆形图片
    public void displayCricleImage(Context context, File file, ImageView imageView) {
        Glide.with(context)
                .load(file)
                .centerCrop()
                //.placeholder(R.drawable.two)
                .transform(new GlideCircleTransform(context))
                .into(imageView);

    }

    //将资源ID转为Uri
    public Uri resourceIdToUri(Context context, int resourceId) {
        return Uri.parse(ANDROID_RESOURCE + context.getPackageName() + FOREWARD_SLASH + resourceId);
    }
}
=====================================
这样就实现简单的加载了 其实还有很多问题 比如：加载圆形图片的时候 如果默认的图片是长方形 加载出来的就会是椭圆。
还有 如果在listview中使用的话 还要考虑设置tag等 具体的还有很多问题。慢慢看吧。