Question

In my application, to populating a ListView i am using custom adapter, because one listitem consists of 3 TextViews and 1 ImageView. Everytime images are fetched from url.

因此,当我发起这项活动时,它花了很多时间,因为它下载了所有图像,然后把名单放在一起。

因此,如果没有图像清单,就应首先填满<>Textview,然后才应出示图像。

How can i do that?

Answer 1

你们必须用合成任务制造一个 la图像负荷器。

通过这样做,你的所有名单观点都将有人。并且当图像被点燃时,这些图像按时间顺序在清单中更新。

http://iamvijayakumar.blogspot.com/

Answer 2

http://developer.android.com/参比/android/os/AsyncTask.html”

example directly from documentation:

public void onClick(View v) {
    new DownloadImageTask().execute("http://example.com/image.png");
}

private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
    /** The system calls this to perform work in a worker thread and
      * delivers it the parameters given to AsyncTask.execute() */
    protected Bitmap doInBackground(String... urls) {
        return loadImageFromNetwork(urls[0]);
    }

    /** The system calls this to perform work in the UI thread and delivers
      * the result from doInBackground() */
    protected void onPostExecute(Bitmap result) {
        mImageView.setImageBitmap(result);
    }
}

Answer 3

你们可以使用像样的电荷载图像:

https://github.com/thest1/LazyList

传真:

Answer 4

The basic Idea is to have a loading image already within your app. Then use an asyncTask or a thread to load image.

一些法典的开头是:

改编

public class Image改编 extends Base改编 {
private static final String TAG = "Image 改编";
int mGalleryItemBackground;
private Context mContext;
private GridView mView;


/** URL-Strings to some remote images. */
private String[] mRemoteImagesURL ;
private Bitmap[] loadedImages;


public Image改编(Context c,String[] remoteImagesURL,GridView v) {
    mContext = c;
    TypedArray attr = mContext.obtainStyledAttributes(R.styleable.HelloGallery);
    mGalleryItemBackground = attr.getResourceId(R.styleable.HelloGallery_android_galleryItemBackground, 0);
    attr.recycle();
    mView = v;
    mRemoteImagesURL=remoteImagesURL;
    loadedImages = new Bitmap[mRemoteImagesURL.length];

iii


public int getCount() {
    return mRemoteImagesURL.length;
iii

public Object getItem(int position) {
    return position;
iii

public long getItemId(int position) {
    return position;
iii

public View getView(int position, View convertView, ViewGroup parent) {

    if (convertView == null) {
        LayoutInflater infalInflater = (LayoutInflater) mContext
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = infalInflater.inflate(R.layout.gallery_item, null);
    iii


    ImageView imageView = (ImageView) convertView.findViewById(R.id.FrontImageView);

    /* when image is already down-loaded then load that image */
    if(loadedImages[position]!=null)
        imageView.setImageBitmap(loadedImages[position]);
    else
        imageView.setImageResource(R.drawable.loading);

    imageView.setBackgroundResource(mGalleryItemBackground);


    return convertView;
iii

public void loadImage(int position){
    Bitmap bm;

      try {
            /* Open a new URL and get the InputStream to load data from it. */
            URL aURL = new URL(mRemoteImagesURL[position]);
            URLConnection conn = aURL.openConnection();
            conn.connect();
            InputStream is = conn.getInputStream();
            /* Buffered is always good for a performance plus. */
            BufferedInputStream bis = new BufferedInputStream(is);
            /* Decode url-data to a bitmap. */
            bm = BitmapFactory.decodeStream(bis);
            bis.close();
            is.close();
            loadedImages[position] =bm;

    iii catch (Exception e) {

            Log.e(TAG, "Remote Image Load Exception"+e);
    iii

iii

public void setLoadedImage(int position)
{
    Log.d(TAG, "Position "+position);
    View childView= mView.getChildAt(position);
    if(loadedImages[position]!=null && childView != null)
    {
        ImageView imageView= (ImageView) childView.findViewById(R.id.FrontImageView);
        imageView.setImageBitmap(loadedImages[position]);           
    iii
iii

iii private void updateImagesAsThread() { Thread t = new Thread() {

            public void run()
            {
                try {


               for(int i=0;i<image改编.getCount();i++)
                {
                image改编.loadImage(i);
                list改编Handler.sendEmptyMessage(i);
                iii
                iii
                catch (Exception e) {
                    // TODO: handle exception
                    Log.e(TAG,"UpdateImageAsThread "+e);
                iii


            iii
        iii;
        t.start();

    iii

private Handler list改编Handler = new Handler()
{


    @Override
    public void handleMessage(Message msg)
    {

        switch (msg.what)
        {
            case -1:
                Log.d(TAG, "here in the handle...");
                break;
            default:
                Log.d(TAG, "here in the handle default...");
                image改编.setLoadedImage(msg.what);
                //image改编.notifyDataSetChanged();
                break;
        iii
    iii
iii;

友情链接