Android从URL设置ListView图像

Question

我有一个包含图片的Newsfeed（ListView）。 我想从网络上加载图像并用于我的活动中。 所以我在MainActivity的OnCreate（）中有这个：

    String url = "http://m.c.lnkd.licdn.com/mpr/pub/image-Zo8GfnPFe2SPJa2kv-bwRRP7GivkI_DrZ_bw2xHFJLOvI4T0No8wCrLzo95B7jMdzre/suneet-choudhary.jpg";
    Drawable x = LoadImageFromWebOperations(url);
        FeedUser FeedUser_data[] = new FeedUser[]
        {
            new FeedUser(x, "Usename1", "What the hell man."),
            new FeedUser(x, "Username2", "Why not sunny leone."),
        };

        FeedUserAdapter adapter = new FeedUserAdapter(this, 
                R.layout.listview_item_row, FeedUser_data);

        lv = (ListView)findViewById(R.id.list);
        lv.setAdapter(adapter);

    public static Drawable LoadImageFromWebOperations(String url) {
        try {
            InputStream is = (InputStream) new URL(url).getContent();
            Drawable d = Drawable.createFromStream(is, "src name");
            return d;
        } catch (Exception e) {
            return null;
        }
    }

这是我的FeedUser.java

public class FeedUser {
    public Drawable icon;
    public String title;
    public String review;
    public FeedUser(){
        super();
    }

    public FeedUser(Drawable x, String title, String review) {
        super();
        this.icon = x;
        this.title = title;
        this.review = review;
    }
}

下面是FeedUser适配器：

public class FeedUserAdapter extends ArrayAdapter<FeedUser>{

    Context context; 
    int layoutResourceId;    
    FeedUser data[] = null;

    public FeedUserAdapter(Context context, int layoutResourceId, FeedUser[] data) {
        super(context, layoutResourceId, data);
        this.layoutResourceId = layoutResourceId;
        this.context = context;
        this.data = data;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View row = convertView;
        FeedUserHolder holder = null;

        if(row == null)
        {
            LayoutInflater inflater = ((Activity)context).getLayoutInflater();
            row = inflater.inflate(layoutResourceId, parent, false);

            holder = new FeedUserHolder();
            holder.imgIcon = (ImageView)row.findViewById(R.id.imgIcon);
            holder.txtTitle = (TextView)row.findViewById(R.id.UserName);
            holder.txtReview = (TextView)row.findViewById(R.id.ReviewText);

            row.setTag(holder);
        }
        else
        {
            holder = (FeedUserHolder)row.getTag();
        }

        FeedUser FeedUser = data[position];
        holder.txtTitle.setText(FeedUser.title);
        holder.imgIcon.setImageDrawable(FeedUser.icon);
        holder.txtReview.setText(FeedUser.review);

        return row;
    }

    static class FeedUserHolder
    {
        ImageView imgIcon;
        TextView txtTitle;
        TextView txtReview;
    }
}

现在它没有显示任何错误，但是图像也不会加载。 我是一个初学者，所以不确定可能出什么问题了：/

Answer 1

根据您的要求，您可以使用Universal Image Loader库（ https://github.com/nostra13/Android-Universal-Image-Loader ）或Picasso库（ http://www.bignerdranch.com/blog/solving-the -android-image-loading-problem-volley-vs-picasso / ）。

或通过以下链接：-

延迟加载ListView中的图像

Answer 2

您可以尝试使用以下易于使用且仍通过新功能和错误解决方案维护的库：

https://github.com/nostra13/Android-Universal-Image-Loader

Answer 3

如果您下载http://github.com/square/picasso并使用此代码，它将为您工作，并且所有图像下载工作均由毕加索完成

String url = "http://m.c.lnkd.licdn.com/mpr/pub/image-Zo8GfnPFe2SPJa2kv-bwRRP7GivkI_DrZ_bw2xHFJLOvI4T0No8wCrLzo95B7jMdzre/suneet-choudhary.jpg";
    FeedUser FeedUser_data[] = new FeedUser[] {
        new FeedUser(url, "Usename1", "What the hell man."),
        new FeedUser(url, "Username2", "Why not sunny leone."),
    };

    FeedUserAdapter adapter = new FeedUserAdapter(this, 
            R.layout.listview_item_row, FeedUser_data);

    lv = (ListView)findViewById(R.id.list);
    lv.setAdapter(adapter);

}

public class FeedUser {
     public String iconUrl;
     public String title;
     public String review;
} 

public FeedUser(String url, String title, String review) {
    this.iconUrl = url;
    this.title = title;
    this.review = review;
}

}

公共类FeedUserAdapter扩展了ArrayAdapter {

Context context; 
int layoutResourceId;    
FeedUser data[] = null;

public FeedUserAdapter(Context context, int layoutResourceId, FeedUser[] data) {
    super(context, layoutResourceId, data);
    this.layoutResourceId = layoutResourceId;
    this.context = context;
    this.data = data;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View row = convertView;
    FeedUserHolder holder = null;

    if(row == null) {
        LayoutInflater inflater = ((Activity)context).getLayoutInflater();
        row = inflater.inflate(layoutResourceId, parent, false);

        holder = new FeedUserHolder();
        holder.imgIcon = (ImageView)row.findViewById(R.id.imgIcon);
        holder.txtTitle = (TextView)row.findViewById(R.id.UserName);
        holder.txtReview = (TextView)row.findViewById(R.id.ReviewText);

        row.setTag(holder);
    }
    else {
        holder = (FeedUserHolder)row.getTag();
    }

    FeedUser FeedUser = data[position];
    holder.txtTitle.setText(FeedUser.title);

    Picasso.with(context).load(FeedUser.iconUrl).fit().noFade().into(holder.imgIcon);
    holder.txtReview.setText(FeedUser.review);

    return row;
}

static class FeedUserHolder {
    ImageView imgIcon;
    TextView txtTitle;
    TextView txtReview;
}