在textview中加载Html.fromHtml中的图像(http url图像,Base64 url​​图像)

Question

我有一个textview,其中我正在显示一个论坛帖子的内容,使用rte在网站上输入,内容涉及图像,类型web url和类型Base64.. Html.fromHtml的默认实现替换所有img标签小广场..

我在SO上寻找使用Html.fromHtml方法从url加载图像的解决方案,结果有办法做到这一点,我们可以将ImageGetter传递给函数..我发现这个很棒的答案实现了url fetch部分,但是这个失败和崩溃应用程序时,内容具有的图像Base64 ..

我看了一种为Base64src 创建图像的方法,但没有一个解决方案正在工作,如果有人已经实现了整个解决方案,那就太棒了.如果有人只有Base64部分请提供我将整合两个..

Answer 1

最后花了几个小时后,我找到了Base64图像的解决方案..我在这里发布完整的解决方案..

我想再次感谢/sf/answers/1093213901/的基本答案.

原来我使用的答案作为参考只是这个asnwer的副本..

URLDrawable.java

import android.graphics.Canvas;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;

public class URLDrawable extends BitmapDrawable {
    // the drawable that you need to set, you could set the initial drawing
    // with the loading image if you need to
    protected Drawable drawable;

    @Override
    public void draw(Canvas canvas) {
        // override the draw to facilitate refresh function later
        if(drawable != null) {
            drawable.draw(canvas);
        }
    }
}

URLImageParser.java

import java.io.InputStream;
import java.net.URL;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.text.Html.ImageGetter;
import android.util.Base64;
import android.view.View;

public class URLImageParser implements ImageGetter {
    Context context;
    View container;

    public URLImageParser(View container, Context context) {
        this.context = context;
        this.container = container;
    }

    public Drawable getDrawable(String source) {   
        if(source.matches("data:image.*base64.*")) {
            String base_64_source = source.replaceAll("data:image.*base64", "");
            byte[] data = Base64.decode(base_64_source, Base64.DEFAULT);
            Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);                
            Drawable image = new BitmapDrawable(context.getResources(), bitmap);
            image.setBounds(0, 0, 0 + image.getIntrinsicWidth(), 0 + image.getIntrinsicHeight()); 
            return image;
        } else {
            URLDrawable urlDrawable = new URLDrawable();
            ImageGetterAsyncTask asyncTask = new ImageGetterAsyncTask(urlDrawable);
            asyncTask.execute(source);          
            return urlDrawable; //return reference to URLDrawable where We will change with actual image from the src tag
        }        
    }

    public class ImageGetterAsyncTask extends AsyncTask<String, Void, Drawable> {
        URLDrawable urlDrawable;

        public ImageGetterAsyncTask(URLDrawable d) {
            this.urlDrawable = d;
        }

        @Override
        protected Drawable doInBackground(String... params) {
            String source = params[0];
            return fetchDrawable(source);
        }

        @Override
        protected void onPostExecute(Drawable result) {         
            urlDrawable.setBounds(0, 0, 0 + result.getIntrinsicWidth(), 0 + result.getIntrinsicHeight()); //set the correct bound according to the result from HTTP call            
            urlDrawable.drawable = result; //change the reference of the current drawable to the result from the HTTP call          
            URLImageParser.this.container.invalidate(); //redraw the image by invalidating the container
        }

        public Drawable fetchDrawable(String urlString) {
            try {
                InputStream is = (InputStream) new URL(urlString).getContent();
                Drawable drawable = Drawable.createFromStream(is, "src");
                drawable.setBounds(0, 0, 0 + drawable.getIntrinsicWidth(), 0 + drawable.getIntrinsicHeight()); 
                return drawable;
            } catch (Exception e) {
                return null;
            } 
        }
    }
}

用法:

TextView comment_content_container = ((TextView)findViewById(R.id.comment_content));
comment_content_container.setText(Html.fromHtml(comment.content, new URLImageParser(comment_content_container, this), null));

如果有人知道更好的正则表达式Base64,请回复我会更新答案..