android - 图像显示为gridview

Question

我想使用 imageurl 显示来自 mysql 服务器(在本地主机中测试)的图像，我的服务器上的 filder 中有图像，在 android 客户端应用程序中作为 gridview 以及文本。如何在我的代码中使用 imageurl？我的主菜单.java

public class MainMenu extends Activity {



    GridView gridView;

    static final String[] MOBILE_OS = new String[] { 
        "Android", "iOS","Windows", "Blackberry" };

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.mainmenu_list);


        gridView = (GridView) findViewById(R.id.gridView1);

        gridView.setAdapter(new ImageAdapter(this, MOBILE_OS));

        gridView.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View v,
                    int position, long id) {
                Toast.makeText(
                   getApplicationContext(),
                   ((TextView) v.findViewById(R.id.grid_item_label))
                   .getText(), Toast.LENGTH_SHORT).show();

            }
        });

    }

}

我的 imageadapter.java:

public class ImageAdapter extends BaseAdapter {
private Context context;
private final String[] mobileValues;
    public ImageAdapter(Context context, String[] mobileValues) {
    this.context = context;
    this.mobileValues = mobileValues;
}

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

    LayoutInflater inflater = (LayoutInflater) context
        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    View gridView;

    if (convertView == null) {

        gridView = new View(context);

        // get layout from list.xml
        gridView = inflater.inflate(R.layout.list, null);

        // set value into textview
        TextView textView = (TextView) gridView
                .findViewById(R.id.grid_item_label);
        textView.setText(mobileValues[position]);

        // set image based on selected text
        ImageView imageView = (ImageView) gridView
                .findViewById(R.id.grid_item_image);

        String mobile = mobileValues[position];

        if (mobile.equals("Windows")) {
            imageView.setImageResource(R.drawable.imggrid);
        } else if (mobile.equals("iOS")) {
            imageView.setImageResource(R.drawable.imggrid);
        } else if (mobile.equals("Blackberry")) {
            imageView.setImageResource(R.drawable.imggrid);
        } else {
            imageView.setImageResource(R.drawable.imggrid);
        }

    } else {
        gridView = (View) convertView;
    }

    return gridView;
}

@Override
public int getCount() {
    return mobileValues.length;
}

@Override
public Object getItem(int position) {
    return null;
}

@Override
public long getItemId(int position) {
    return 0;
}

我不知道如何在我的代码中使用以下内容:

try {
            URL url = new URL(imageFileURL);
            URLConnection conn = url.openConnection();                   
            HttpURLConnection httpConn = (HttpURLConnection)conn;
            httpConn.setRequestMethod("GET");
            httpConn.connect();               
            if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) {
             InputStream inputStream = httpConn.getInputStream();                     
             Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
             inputStream.close();
             img.setImageBitmap(bitmap);
            }
           } catch (MalformedURLException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
           } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
           }

Answer 1

将图片下载代码放在AsyncTask中。 Here is the explanation .在您的 getView 方法中执行一个 asynctask 实例，即每次获取一张图像。

private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
 ImageView mImageView;
 public void setImageView(ImageView img) {
      mImageView = img;
 }

 protected Bitmap doInBackground(String... urls) {
     return loadImageFromNetwork(urls[0]);
 }

 protected void onPostExecute(Bitmap result) {
     mImageView.setImageBitmap(result);
 }

在执行 AsyncTask 之前调用 task.setImageView(yourImageViewinGrid) 以让它知道在下载后在哪里设置图像。