0

何らかの理由で、インターネットを使用して URL からビットマップ イメージを表示しようとすると、Blackberry アプリケーションがクラッシュします。

このdownloadImage()関数は、stackoverflow の他の関数に比べて非常に理解しやすく、従うのが簡単であることがわかりました。他の人には、その機能を実装する方法の例がありませんでした。関数 downloadImage を何度もテストしましたが、すべて失敗しました。

コード例で説明してください。ありがとう。

とにかく、コンパイラはこの時点で停止します:

g.drawBitmap(10, y + 6, 50, 50, imageBmp, 0, 0);

コード全体は次のとおりです。

package parsepack;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Vector;

import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;
import javax.microedition.io.StreamConnection;

import net.rim.device.api.system.Bitmap;
import net.rim.device.api.system.DeviceInfo;
import net.rim.device.api.system.Display;
import net.rim.device.api.system.EncodedImage;
import net.rim.device.api.ui.DrawStyle;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.FieldChangeListener;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.Manager;
import net.rim.device.api.ui.UiApplication;
import net.rim.device.api.ui.component.BitmapField;
import net.rim.device.api.ui.component.Dialog;
import net.rim.device.api.ui.component.LabelField;
import net.rim.device.api.ui.component.ListField;
import net.rim.device.api.ui.component.ListFieldCallback;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.container.VerticalFieldManager;
import net.rim.device.api.xml.parsers.DocumentBuilder;
import net.rim.device.api.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;



public class xmlparsing extends UiApplication implements ListFieldCallback, FieldChangeListener 
{

    public static void main(String[] args) throws IOException
    {
    xmlparsing app = new xmlparsing();
    app.enterEventDispatcher();
    }


public long mycolor ;
Connection _connectionthread;     
private static ListField _list;
private static Vector listElements = new Vector();
private static Vector listPrice = new Vector();
private static Vector listAbstract = new Vector();
private static Vector listIcon = new Vector();
private Vector listInfoVector = new Vector();
public MainScreen screen = new MainScreen();
Bitmap imageBmp = null;
VerticalFieldManager mainManager;
VerticalFieldManager subManager;
UiApplication ui = UiApplication.getUiApplication(); 


public  xmlparsing() throws IOException 
{ 
    super();
    pushScreen(screen);

    final Bitmap backgroundBitmap = Bitmap.getBitmapResource("blackbackground.png");

     mainManager = new VerticalFieldManager(Manager.NO_VERTICAL_SCROLL | Manager.NO_VERTICAL_SCROLLBAR )
        {

         public void paint(Graphics graphics)
          {
            graphics.drawBitmap(0, 0, Display.getWidth(),Display.getHeight(),backgroundBitmap, 0, 0);

            super.paint(graphics);
          }

        };

        subManager = new VerticalFieldManager(Manager.VERTICAL_SCROLL | Manager.VERTICAL_SCROLLBAR )
        {
            protected void sublayout( int maxWidth, int maxHeight )
            {
                int displayWidth = Display.getWidth();
                int displayHeight = Display.getHeight();

                super.sublayout( displayWidth, displayHeight);
                setExtent( displayWidth, displayHeight);
            }
        };        


    screen.add(mainManager);





    _list = new ListField()
    {
        public void paint(Graphics graphics)
        {
            graphics.setColor((int) mycolor);
            super.paint(graphics);
        }
        protected boolean navigationClick(int status, int time)
        {
            try
            {
                //navigate here to another screen
                ui.pushScreen(new ResultScreen());
            }
            catch(Exception e)
            {
                System.out.println("Exception:-  : navigationClick() "+e.toString());
            }
            return true;
        }
    }; 
    mycolor = 0x00FFFFFF;
        _list.invalidate();
        _list.setEmptyString("* Feeds Not Available *", DrawStyle.HCENTER);
    _list.setRowHeight(70);
    _list.setCallback(this);
    mainManager.add(subManager);    
   listElements.removeAllElements();
   listPrice.removeAllElements();
   listAbstract.removeAllElements();
   listIcon.removeAllElements();
   _connectionthread = new Connection(); 
   _connectionthread.start();
 }


private class Connection extends Thread
{ 
    public Connection()
    { 
       super(); 
    } 

    public void run() {  
        Document doc;  
        StreamConnection conn = null; 
        InputStream is = null;  
        try {           

            conn = (StreamConnection) Connector.open("http://imforchange.org/international-movement-for-change/testing/data.xml"+";deviceside=true");           

            DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();  
            docBuilderFactory.setIgnoringElementContentWhitespace(true);
            docBuilderFactory.setCoalescing(true);
            DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();    
            docBuilder.isValidating();      
            is = conn.openInputStream();    
            doc = docBuilder.parse(is);     
            doc.getDocumentElement().normalize();   
            NodeList list1 = doc.getElementsByTagName("eventName"); 
                for (int i = 0; i < list1.getLength(); i++) {    
                Node textNode = list1.item(i).getFirstChild();  
                listElements.addElement(textNode.getNodeValue());

                } 
                NodeList list2 = doc.getElementsByTagName("eventPrice"); 
                for (int i = 0; i < list2.getLength(); i++) {    
                Node textNode = list2.item(i).getFirstChild();  
                listPrice.addElement(textNode.getNodeValue());

                } 

                NodeList list3 = doc.getElementsByTagName("eventAbstract"); 
                for (int i = 0; i < list3.getLength(); i++) {    
                Node textNode = list3.item(i).getFirstChild();  
                listAbstract.addElement(textNode.getNodeValue());

                }

                NodeList list4 = doc.getElementsByTagName("eventIcon"); 
                for (int i = 0; i < list4.getLength(); i++) {    
                Node textNode = list4.item(i).getFirstChild();  
                listIcon.addElement(textNode.getNodeValue());

                }



                } catch (Exception e) {   
                    System.out.println(e.toString());                     
                    } finally {   
                        if (is != null) {  
                        try { is.close(); 
                        } catch (IOException ignored) {}   
                        }        if (conn != null) {  
                            try { conn.close(); } 
                            catch (IOException ignored) {} 
                            }    } UiApplication.getUiApplication().invokeLater(new Runnable() { 
                                public void run() {         
                                _list.setSize(listElements.size()); 
                                subManager.add(_list);
                                screen.invalidate();
                                }   
                                });
                            }





}




public void drawListRow(ListField list, Graphics g, int index, int y, int w) 
{  


    String text = (String)listElements.elementAt(index);
    String price = (String)listPrice.elementAt(index);
    String textAbstract = (String)listAbstract.elementAt(index);
    int yPos = 0+y;
    g.drawLine(0, yPos, w, yPos);
    g.drawText(text, 5, 15+y, 0, w);
    g.drawText("$"+price, 5, 15+y, DrawStyle.RIGHT, w-7);
    g.drawText(textAbstract, 5, 40+y, 0, w);



    // image to display
    String imageUrl = (String)listIcon.elementAt(index);
    imageBmp = downloadImage(imageUrl);
    g.drawBitmap(10, y + 6, 50, 50, imageBmp, 0, 0);
}



public Object get(ListField list, int index) 
{
    return listElements.elementAt(index); 
} 
public int indexOfList(ListField list, String prefix, int string) 
{ 
    return listElements.indexOf(prefix, string); 
} 
public int getPreferredWidth(ListField list) 
{ 
 return Display.getWidth(); 
}

/*Regarding the warning about insert(), that's just because you're not using it anywhere. 
 * It look like you've added that method to allow code outside the xmlparsing class to 
 * be able to insert items into the list. Maybe that's what you want, but you just 
 * haven't yet written the other code to use that method. I see you having at least a few choices:
 */
public void insert(String toInsert, int index) {
    listElements.addElement(toInsert);
    }

public void fieldChanged(Field field, int context) {


}


public static Bitmap downloadImage(String url)
{
InputStream iStream = null;
EncodedImage bitmap;
    HttpConnection httpConnection = null;

        try
        {
                    httpConnection = (HttpConnection) Connector.open(url, Connector.READ_WRITE);

            httpConnection.setRequestMethod(HttpConnection.GET);
            int responseCode = httpConnection.getResponseCode();
            if (responseCode == HttpConnection.HTTP_OK) {


                iStream = httpConnection.openInputStream();
                ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();

                byte[] buffer = new byte[256];
                int len = 0, imageSize = 0;

                while (-1 != (len = iStream.read(buffer))) {
                    byteArrayOutputStream.write(buffer);
                    imageSize += len;
                }

                byteArrayOutputStream.flush();
                byte[] imageData = byteArrayOutputStream.toByteArray();
                byteArrayOutputStream.close();
                bitmap = EncodedImage.createEncodedImage(imageData, 0, imageSize);                                      
                Bitmap bmp = bitmap.getBitmap();

return bmp;
            }
            }
            catch (Exception e)
            {                      
            }
return null;                  
}




}
4

2 に答える 2

1

私はあなたの方法を見ます: downloadImage(String url)。その長いコード。それほど必要ありません。

この方法を試してください：

public static Bitmap getImage(String url)
{
    Bitmap image;
    HttpConnection connection=null;
    InputStream is=null;
    try
    {
        connection=(HttpConnection)Connector.open(Utility.escapeHTML(url));
        int response=connection.getResponseCode();
        if(response==HttpConnection.HTTP_OK)
        {   
            is=connection.openInputStream();
            byte[] data=IOUtilities.streamToBytes(is);
            connection.close();
            image=Bitmap.createBitmapFromBytes(data,0,data.length,1);
        }
        else
        {
                image=ResourceList.dummyBit;//noimage.png               
        }
    }
    catch (Exception e) 
    {
        image=ResourceList.dummyBit;//noimage.png               
    }
    finally
    {
        try 
        {
            if (is != null)
                is.close();
            if (connection != null)
                connection.close();
        }
        catch (Exception e) {}
    }
    return image;
}

これを試して、私に知らせてください。

escapeHTML(String str)メソッドは以下のとおりです。

public static String escapeHTML(String s)
{
    StringBuffer sb = new StringBuffer();
    int n = s.length();
       for (int i = 0; i < n; i++) {
          char c = s.charAt(i);
          switch (c) {
             case ' ': sb.append("%20"); break;
             default:  sb.append(c); break;
        }
    }
    return sb.toString();
}
于 2012-10-20T08:02:51.957 に答える
1

WebURL から BlackBerry 画面に画像を表示したい場合。まず、BitMap refrence を取得する必要があります。

以下のコードを確認できます。

コードは入力を WebURL として受け取り、ビットマップ参照を返します。

import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;
import net.rim.device.api.io.IOUtilities;
import net.rim.device.api.system.Bitmap;
import net.rim.device.api.system.EncodedImage;

        public class GetImage {
        public static Bitmap connectServerForImage(String url) {
        HttpConnection httpConnection = null;
        DataOutputStream httpDataOutput = null;
        InputStream httpInput = null;
        int rc;
        Bitmap bitmp = null;
        try {
        httpConnection = (HttpConnection) Connector.open(url);
        rc = httpConnection.getResponseCode();
        if (rc != HttpConnection.HTTP_OK) {
        throw new IOException("HTTP response code: " + rc);
        }
        httpInput = httpConnection.openInputStream();
        InputStream inp = httpInput;
        byte[] b = IOUtilities.streamToBytes(inp);
        EncodedImage hai = EncodedImage.createEncodedImage(b, 0, b.length);
        return hai.getBitmap();
        } catch (Exception ex) {
        // System.out.println("URL Bitmap Error........" + ex.getMessage());
        } finally {
        try {
        if (httpInput != null)
        httpInput.close();
        if (httpDataOutput != null)
        httpDataOutput.close();
        if (httpConnection != null)
        httpConnection.close();
        } catch (Exception e) {
        e.printStackTrace();
        }
        }
        return bitmp;
        }
          }

最後に、BlackBerry 画面に画像を表示する場合は、以下の方法を使用します。

g.drawBitmap(xpos, ypos, w, h, image, 0, 0);//pass the Bitmap reference Here
于 2012-10-20T09:34:24.503 に答える