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我正在尝试创建一个复选框，并且在此对象列表下方。我试图专注于复选框，但它既不可聚焦也不可检查。焦点位于下面列表的第一个元素上。

我如何才能关注复选框并使其可选中？在这里，复选框位于我添加列表的 VerticalFieldManager 中。

在此处输入图像描述

这里我要添加两件事：一个是水平字段管理器（onlineCheckBoxHfm），另一个是 objectListField（buddyList）。

现在的问题是，默认焦点在列表的第一个元素上，我无法将焦点放在放置 CheckBox 的 Horizo​​ntalFieldManager 上。由于Horizo​​ntalFieldManager 上没有焦点，所以我无法检查复选框。

public class BuddyMenuItem extends VerticalFieldManager implements FieldChangeListener{   

 public BuddyMenuItem(BuddyListField buddyList) {

        _bitmap = EncodedImage.
        getEncodedImageResource("buddies_header.png");
        mainMenuBmp = new BitmapField(Constant.sizePic(_bitmap, _bitmap.getHeight(), Display.getWidth()));

        HorizontalFieldManager onlineCheckBoxHfm=new HorizontalFieldManager(HorizontalFieldManager.USE_ALL_WIDTH);
        _onlineCheckBox=new CheckboxField("Online",false,CheckboxField.FIELD_LEFT|CheckboxField.FOCUSABLE);
        _onlineCheckBox.setChangeListener(this);

        onlineCheckBoxHfm.add(_onlineCheckBox);
        onlineCheckBoxHfm.add(new NullField(NullField.FOCUSABLE));
//      add(mainMenuBmp);
        add(onlineCheckBoxHfm);
        add(buddyList);
    }

BuddyListField 类如下：

import java.util.Vector;

import net.rim.device.api.system.Bitmap;
import net.rim.device.api.system.Display;
import net.rim.device.api.ui.Color;
import net.rim.device.api.ui.DrawStyle;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.Keypad;
import net.rim.device.api.ui.TouchEvent;
import net.rim.device.api.ui.Touchscreen;
import net.rim.device.api.ui.component.ListField;
import net.rim.device.api.ui.component.ObjectListField;

import com.np.naijapings.Buddy;
import com.np.naijapings.NaijapingsMain;

public class BuddyListField extends ObjectListField {
    public static final Bitmap offlineIcon = Bitmap.getBitmapResource("offline.png");
    public static final Bitmap awayIcon = Bitmap.getBitmapResource("away.png");
    public static final Bitmap busyIcon = Bitmap.getBitmapResource("busy.png");
    public static final Bitmap onlineIcon = Bitmap.getBitmapResource("online.png");
    public static final Bitmap unreadIcon = Bitmap.getBitmapResource("unread.png");
    public static final Bitmap maleIcon=Bitmap.getBitmapResource("male.png");

    public static final Bitmap[] statusIcon = new Bitmap[]{offlineIcon, awayIcon, busyIcon, onlineIcon};

    public static Vector buddyVector;
    public static int onlineBuddyCount=0;
    private final NPingsMain nPings;
    public static boolean showOnlineBuddy=false;

    private Bitmap _chatBmp=Bitmap.getBitmapResource("chat.png");

    public BuddyListField(NPingsMain n,boolean showOnlineBuddy) {
        nPings = n;
        buddyVector = new Vector();
        this.showOnlineBuddy=showOnlineBuddy;
    }

    public Buddy getBuddyAt(int index) {
        return (Buddy)buddyVector.elementAt(index);     
    }

    protected boolean keyChar(char key, int status, int time) {
        int idx;
        switch(key) {
        case Keypad.KEY_ENTER:
            idx = this.getSelectedIndex();
            if (idx >= 0) {
                NPingsMain.currentBuddy = (Buddy)buddyVector.elementAt(idx);
                NPingsMain.openBuddy(NPingsMain.currentBuddy);
            }
            return true;

        case 'e':
            idx = this.getSelectedIndex()-1;
            if (idx >= 0) {
                this.setSelectedIndex(idx);
            }
            return true;

        case 's':
            return true;

        case 'f':
            return true;

        case 'x':
            idx = this.getSelectedIndex()+1;
            if (idx > 0 && idx < this.getSize()) {
                this.setSelectedIndex(idx);
            }
            return true;

        case 't':
            if (this.getSize() > 0) {
                this.setSelectedIndex(0);
            }
            return true;
        }

        return false;
    }
    protected boolean navigationClick(int status, int time) {
        int idx = this.getSelectedIndex();
        if(Touchscreen.isSupported()){
            if (idx >= 0) {
                nPings.currentBuddy = (Buddy)buddyVector.elementAt(idx);
                if((nPings.currentBuddy.status==0x00000003)||(nPings.currentBuddy.status==0x00000002)||(nPings.currentBuddy.status==0x00000001)){
                    NPingsMain.openBuddy(nPings.currentBuddy);
                }
            }
            return false;
        }else{

            if (idx >= 0) {
                nPings.currentBuddy = (Buddy)buddyVector.elementAt(idx);
                if((nPings.currentBuddy.status==0x00000003)||(nPings.currentBuddy.status==0x00000002)||(nPings.currentBuddy.status==0x00000001)){
                    NPingsMain.openBuddy(nPings.currentBuddy);
                }
            }
            return false;
        }
    }
    protected boolean touchEvent(TouchEvent message) {
        //if(message.getEvent()==TouchEvent.CLICK){
            int idx;
            switch(TouchEvent.CLICK) {
            case TouchEvent.CLICK:
                idx = this.getSelectedIndex();
                if (idx >= 0) {
                    nPings.currentBuddy = (Buddy)buddyVector.elementAt(idx);
                    if((nPings.currentBuddy.status==0x00000003)||(nPings.currentBuddy.status==0x00000002)||(nPings.currentBuddy.status==0x00000001)){
                        NPingsMain.openBuddy(nPings.currentBuddy);
                    }
                }
                return true;

            case 'e':
                idx = this.getSelectedIndex()-1;
                if (idx >= 0) {
                    this.setSelectedIndex(idx);
                }
                return true;

            case 's':
                return true;

            case 'f':
                return true;

            case 'x':
                idx = this.getSelectedIndex()+1;
                if (idx > 0 && idx < this.getSize()) {
                    this.setSelectedIndex(idx);
                }
                return true;

            case 't':
                if (this.getSize() > 0) {
                    this.setSelectedIndex(0);
                }
                return true;
            }

        //  return false;

    //  }
        return super.touchEvent(message);
    }

    public void buddyReposition(Buddy b) {
        int index = buddyVector.indexOf(b);
        buddyReposition(index);
    }

    public void buddyReposition(int oldIndex) {
        Buddy b = (Buddy)buddyVector.elementAt(oldIndex);
        int newIndex = 0;

        if (b.unread) {
            newIndex = 0;
        } else {
            while (newIndex < buddyVector.size() &&
                    ((b == (Buddy)buddyVector.elementAt(newIndex)) || 
                            ((Buddy)buddyVector.elementAt(newIndex)).unread || 
                            (b.status < ((Buddy)buddyVector.elementAt(newIndex)).status)))
                ++newIndex;
        }

        newIndex = (oldIndex < newIndex) ? (newIndex-1) : newIndex;

        if (oldIndex != newIndex) {
            buddyVector.removeElementAt(oldIndex);
            buddyVector.insertElementAt(b, newIndex);
        }

        this.invalidate();
    }

    public int findBuddyIndex(String jid) {
        for (int i = buddyVector.size()-1; i >= 0; i--) {
            if (((Buddy)buddyVector.elementAt(i)).jid.equals(jid))
                return i;
        }

        return -1;
    }

    public Buddy findBuddy(String jid) {
        for (int i = buddyVector.size()-1; i >= 0; i--) {
            if (((Buddy)buddyVector.elementAt(i)).jid.equals(jid))
                return (Buddy)buddyVector.elementAt(i);
        }
        return null;
    }

    public void addBuddy(Buddy b) {
        //CHECK FOR ONLINE BUDDIES  
        buddyVector.addElement(b);
        this.insert(buddyVector.indexOf(b));

    }

    public void deleteBuddy(int index){
        buddyVector.removeElementAt(index);
        this.delete(index);

    }

    public void drawListRow(ListField listField, Graphics graphics, int index, int y, int width) {
        // NOTICE 14 would be consist the icon size

        onlineBuddyCount=0; 
        String bName="";
        Buddy b = (Buddy)buddyVector.elementAt(index);
        if(showOnlineBuddy==true){
            if(b.status==0x00000003||b.status==0x00000002||b.status==0x00000001){

                //DRAW ROW BACKGROUND START
                if (listField.getSelectedIndex() != index) {
                    graphics.setBackgroundColor(index % 2 == 0 ? Color.WHITE
                            : Color.LIGHTGRAY);
                    graphics.clear();
                    listField.setFocus();
                }
                //DRAW ROW BACKGROUND END

                onlineBuddyCount++;
                if(b.name.endsWith("net")){
                    int i=b.name.indexOf("@");
                    bName=b.name.substring(0, i);
                }else{
                    bName=b.name;
                }
                if (b.unread) {
                    graphics.drawBitmap(0, y+3, unreadIcon.getWidth(), unreadIcon.getHeight(),unreadIcon , 0, 0);
                } else {
                    graphics.drawBitmap(0, y+3, unreadIcon.getWidth(), unreadIcon.getHeight(),statusIcon[b.status] , 0, 0);
                }

                graphics.drawText(bName, 25, y, DrawStyle.HDEFAULT, width-12);
                graphics.drawBitmap(Display.getWidth()-_chatBmp.getWidth(), y-6, _chatBmp.getWidth(), _chatBmp.getHeight(), _chatBmp, 0, 0);
            }
        }else{
            //DRAW ROW BACKGROUND START
            if (listField.getSelectedIndex() != index) {
                graphics.setBackgroundColor(index % 2 == 0 ? Color.WHITE
                        : Color.LIGHTGRAY);
                graphics.clear();
                listField.setFocus();
            }
            //DRAW ROW BACKGROUND END

            onlineBuddyCount++;
            if(b.name.endsWith("net")){
                int i=b.name.indexOf("@");
                bName=b.name.substring(0, i);
            }else{
                bName=b.name;
            }
            if (b.unread) {
                graphics.drawBitmap(0, y+3, unreadIcon.getWidth(), unreadIcon.getHeight(),unreadIcon , 0, 0);
            } else {
                graphics.drawBitmap(0, y+3, unreadIcon.getWidth(), unreadIcon.getHeight(),statusIcon[b.status] , 0, 0);
            }

            graphics.drawText(bName, 25, y, DrawStyle.HDEFAULT, width-12);
            graphics.drawBitmap(Display.getWidth()-_chatBmp.getWidth(), y-6, _chatBmp.getWidth(), _chatBmp.getHeight(), _chatBmp, 0, 0);
        }
    }



    public void clearBuddies() {
        if (nPings.buddyList != null) {
            int i = buddyVector.size();
            while (i-- > 0)
                this.delete(0);
            nPings.buddyscreen.delete(nPings.buddyList);
            nPings.buddyList = null;
        }
    }
}
4

1 回答 1

1

我无法运行您的代码，因为其中有太多我没有的（其他类、PNG 等），但我敢打赌您的问题出在此处：

public void drawListRow(ListField listField, Graphics graphics, int index, int y, int width) {

   // other stuff here

      listField.setFocus();

调用setFocus()会将焦点设置在列表字段（BuddyListField）上。所以，你CheckBoxField 实际上是可聚焦的。问题是您添加了复选框字段，然后添加了列表字段。绘制列表字段时，使用drawListRow()，您总是将焦点从复选框移开并将其放回列表字段。

删除对listField.setFocus()...的调用，其中有两个。

drawListRow()用于绘图。我不确定我能想出一个原因，为什么该方法中的任何内容都应该真正改变焦点，这就是这样setFocus()做的。

于 2013-03-19T09:36:28.710 回答