如何在黑莓中重新排列ListField

Question

如何重新排列ListField的项目？我想要点击黑莓（风暴和火炬）触摸手机上的项目。选择后我想（移动和拖动）在另一个列表项目上垂直滚动项目（列表项目在背景中垂直滚动）或屏幕。 滚动后，将项目放在任何位置（在列表字段中）屏幕上。

Answer 1

我也工作自定义列表场。只需点击listitem。点击后U可以垂直移动（选中）listItem。 如果你想放置在屏幕上的任何地方，而不是再次点击触控板。 当你点击它将放置在该位置结帐。 这是我的代码。

public class ListDemo extends MainScreen implements ListFieldCallback { 
private VerticalFieldManager vfm, vfm_List; 
private ListField myList; 
private Vector vector; 
private String[] str_arr; 
int Height = Display.getHeight(); 
int Width = Display.getWidth(); 
int i ; 
boolean bool = true; 
int index = 0; 
private boolean hasFocus = false; 
private boolean b = true; 
public static int curSelected ; 
Channel obj; 

public ListDemo() { 
    vector = new Vector(); 
    for (i = 0; i < 8; i++) { 
     obj = new Channel(); 
     if (i == 0) { 
      obj.setCh_icon("ajtak.jpg"); 
      obj.setCh_Name("NightSuite"); 
      obj.setCh_Move("move.png"); 

     } else if (i == 1) { 
      obj.setCh_icon("cnbc.jpg"); 
      obj.setCh_Name("Shirts"); 
      obj.setCh_Move("move.png"); 

     } else if (i == 2) { 
      obj.setCh_icon("zee.jpg"); 
      obj.setCh_Name("Jeans"); 
      obj.setCh_Move("move.png"); 

     } else if (i == 3) { 
      obj.setCh_icon("astha.jpg"); 
      obj.setCh_Name("Bags"); 
      obj.setCh_Move("move.png"); 

     }else if (i == 4) { 
      obj.setCh_icon("fox_news.jpg"); 
      obj.setCh_Name("Coat"); 
      obj.setCh_Move("move.png"); 

     }else if (i == 5) { 
      obj.setCh_icon("news.jpg"); 
      obj.setCh_Name("Coat"); 
      obj.setCh_Move("move.png"); 

     } else if (i == 6) { 
      obj.setCh_icon("star_news.jpg"); 
      obj.setCh_Name("Coat"); 
      obj.setCh_Move("move.png"); 

     } else { 
      obj.setCh_icon("assiant.jpg"); 
      obj.setCh_Name("Shorts"); 
      obj.setCh_Move("move.png"); 
     } 
     vector.addElement(obj); 
    } 
    init(); 
} 

public void init() { 

    vfm = new VerticalFieldManager(USE_ALL_HEIGHT | USE_ALL_WIDTH) { 

     protected void sublayout(int maxWidth, int maxHeight) { 
      super.sublayout(maxWidth, maxHeight); 
      setExtent(Width, Height); 
     } 
    }; 

    vfm_List = new VerticalFieldManager(VERTICAL_SCROLL 
      | VERTICAL_SCROLLBAR) { 
     protected void sublayout(int maxHeight, int maxWidth) { 
      super.sublayout(maxWidth, maxHeight); 
      setExtent(Width, Height); 
     } 
    }; 
    myList = new ListField() 
    { 
     public void onFocus(int direction){ 
      hasFocus = true; 

     } 
     public void onUnfocus() 
     { 
      hasFocus = false; 
      super.onUnfocus(); 
      invalidate(); 
     } 
     public void paint(Graphics g) { 
      if (hasFocus) 
       { 
        curSelected = getSelectedIndex(); 


       } 
       else 
       { 
        curSelected = -1; 
       } 
      super.paint(g); 

     } 
    }; 
    myList.setCallback(this); 
    myList.setRowHeight(50); 
    myList.setFocusListener(new FocusChangeListener() { 
     public void focusChanged(Field field, int eventType) { 

      if (bool == false) { 
       index = myList.getSelectedIndex(); 
       Channel temp = (Channel) vector 
        .elementAt(index); 
       vector.removeElementAt(index); 
       vector.insertElementAt(temp, curSelected); 
       myList.invalidate(); 

      } 

     } 

    }); 
    for (int i = 0; i < vector.size(); i++) { 
     myList.insert(i); 

    } 
    vfm_List.add(myList); 
    vfm.add(vfm_List); 
    add(vfm); 

} 
protected boolean navigationClick(int status, int time) { 
    if(bool) 
    { 
     bool = false; 
    } 
    else 
    { 
     bool = true; 
    } 


return true; 
} 


public void drawListRow(ListField list, Graphics g, int index, int y, int w) 
{ 
    String text = ((Channel) vector.elementAt(index)).getCh_Name(); 
    Bitmap arrow = Bitmap.getBitmapResource(((Channel) vector.elementAt(index)).getCh_icon()); 
    if(bool == false) 
    { 
     if (g.isDrawingStyleSet(Graphics.DRAWSTYLE_FOCUS)) 
     { 
      Bitmap move = Bitmap.getBitmapResource(((Channel) vector.elementAt(index)).getCh_Move()); 
      g.drawBitmap(Width - 40, y + 13, 25, 25, move, 0, 0); 

     } 
    } 
    g.setBackgroundColor(Color.LIGHTBLUE); 
    g.setColor(Color.BLACK); 
    g.drawBitmap(0, y + 10, 48, 35, arrow, 0, 0); 
    g.drawText(text, 50, y + 18, 0, w); 
    g.setColor(Color.WHITE); 
    invalidate(); 


} 

public Object get(ListField list, int index) { 
    return vector.elementAt(index); 
} 

public int indexOfList(ListField list, String p, int s) { 
    return vector.indexOf(p, s); 
} 

public int getPreferredWidth(ListField list) { 
    return Graphics.getScreenWidth(); 
} 

public void insert(String toInsert, int index) { 
    vector.addElement(toInsert); 
} 

public void erase() { 
    vector.removeAllElements(); 
} 

}

这里是另一个渠道类

public class Channel { 

private String ch_Name; 
private String ch_icon; 
private String ch_move; 

public String getCh_Name() { 
    return ch_Name; 
} 
public void setCh_Name(String ch_Name) { 
    this.ch_Name = ch_Name; 
} 
public String getCh_icon() { 
    return ch_icon; 
} 
public void setCh_icon(String ch_icon) { 
    this.ch_icon = ch_icon; 
} 
public String getCh_Move() { 
    return ch_move; 
} 
public void setCh_Move(String ch_move) { 
    this.ch_move = ch_move; 
} 

}

结帐其对触摸和nontouch工作。

Answer 2

我最近也在致力于定制ListField，我希望以下代码能够帮助您。

在下面的示例中，我定制了一个VerticalFieldManager以为触摸支持和非触摸BB设备创建ListField。在ListField项目

位置可以更改─

- 仅通过DRAG项目并在ListField（用于 触摸支持的设备）的另一种物品掉落

or

- 通过按压在第一项SPACE-BAR，然后在第二 项（为触摸和非触摸设备）。

样本屏幕截图为（触摸）将&掉落下面：

样本屏幕截图为（非触摸）SPACE-BAR按压下面：

在这个示例中，我实现了垂直滚动,ListField并且还创建了传统滚动条。

这里是我的示例屏幕为ListField定制代码：

import net.rim.device.api.system.Characters; 
import net.rim.device.api.ui.Field; 
import net.rim.device.api.ui.Font; 
import net.rim.device.api.ui.Graphics; 
import net.rim.device.api.ui.TouchEvent; 
import net.rim.device.api.ui.XYEdges; 
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.component.ObjectListField; 
import net.rim.device.api.ui.container.MainScreen; 
import net.rim.device.api.ui.container.VerticalFieldManager; 
import net.rim.device.api.ui.decor.BackgroundFactory; 
import net.rim.device.api.ui.decor.Border; 
import net.rim.device.api.ui.decor.BorderFactory; 

public class ListTestScreen extends MainScreen { 
    private VerticalFieldManager mainManager = new VerticalFieldManager(USE_ALL_WIDTH |FIELD_HCENTER); 
    public ListTestScreen() { 
     mainManager.setBackground(BackgroundFactory.createSolidBackground(0x808080)); 
     LabelField lblTitle = new LabelField("FIFA World Cup Country List:",FIELD_HCENTER); 
     lblTitle.setBackground(BackgroundFactory.createSolidBackground(0xF0F0F0)); 
     XYEdges edges = new XYEdges(2, 2, 2, 2); 
     lblTitle.setBorder(BorderFactory.createRoundedBorder(edges, 0xB0B0B0, Border.STYLE_FILLED)); 
     mainManager.add(lblTitle); 
     mainManager.add(new MyList()); 
     LabelField lblOther = new LabelField("Some Other Field",FIELD_HCENTER); 
     lblOther.setBackground(BackgroundFactory.createSolidBackground(0xF0F0F0)); 
     lblOther.setBorder(BorderFactory.createRoundedBorder(edges, 0xB0B0B0, Border.STYLE_FILLED)); 
     mainManager.add(lblOther); 
     add(mainManager); 
    } 
} 

class MyList extends VerticalFieldManager implements ListFieldCallback { 
    private int mouseDownY, mouseUpY; 
    private static int listRowHeight = 30; 
    private int mouseDownRowIndex, mouseUpRowIndex; 
    int firstSelectedRow=-1, secondSelectedRow=-1; 
    private int touchX; 
    private int touchY; 
    private int listVisibleHeight = 250; 
    private int listVisibleWidth = 200; 

    private boolean showShadow = false; 

    private ObjectListField list; 
    private Object[] listData = new Object[] { "South Africa", "Argentina", "Germany", 
      "Australia","Nigeria","Greece","England","Italy","Brazil","Spain","Paraguay","France","Uruguay", 
      "Mexico","Cameroon","Denmark","Portugal","Netherlands","Ghana","Chile", 
      "South Korea","USA","Algeria","Slovenia","Japan","Switzerland","Honduras"}; 

    public MyList() { 
     super(VERTICAL_SCROLL|FIELD_HCENTER); 
     init(); 
     setBackground(BackgroundFactory.createSolidBackground(0xF0F0F0)); 
     XYEdges edges = new XYEdges(6, 6, 6, 6); 
     setBorder(BorderFactory.createRoundedBorder(edges, 0xB0B0B0, Border.STYLE_FILLED)); 
    } 

    private void init() { 
     list = new ObjectListField(FOCUSABLE|Field.FIELD_HCENTER); 
     list.setRowHeight(listRowHeight); 
     list.setCallback(this); 
     list.set(listData); 
     add(list); 
    } 

    private void changeRowPosition(int fromRow, int toRow) { 
     Object temp = listData[fromRow]; 
     int increment = (fromRow<toRow)?1:-1, i; 
     for(i = fromRow+increment; i != toRow+increment ; i=i+increment) { 
      listData[i-increment] = listData[i]; 
     } 
     listData[toRow] = temp; 
     invalidate(); 
    } 

    public void drawListRow(ListField listField, Graphics graphics, int index, 
      int y, int width) { 
     graphics.setFont(Font.getDefault().derive(Font.PLAIN, listRowHeight-8)); 
     graphics.drawText(listData[index].toString(), 25, y + 4); 

    } 

    public Object get(ListField listField, int index) { 
     return listData[index]; 
    } 

    public int getPreferredWidth(ListField listField) { 
     return getPreferredWidth(); 
    } 

    public int indexOfList(ListField listField, String prefix, int start) { 
     return 0; 
    } 

    public int indexOfRowAt(int posY) { 
     int index =(int) Math.floor(posY/listRowHeight * 1.0); 
     return index; 
    } 

    protected void sublayout(int maxWidth, int maxHeight) {  
     super.sublayout(listVisibleWidth, listVisibleHeight); 
     setExtent(listVisibleWidth, listVisibleHeight); 
    } 


    protected boolean keyChar(char ch, int status, int time) { 
     if(ch==Characters.SPACE) { 
      if(firstSelectedRow ==-1) { 
       firstSelectedRow = list.getSelectedIndex(); 
       return true; 
      } else { 
       secondSelectedRow = list.getSelectedIndex(); 
       if(firstSelectedRow == secondSelectedRow) { 
        firstSelectedRow = secondSelectedRow = -1; 
        invalidate(); 
        return true; 
       } else { 
        changeRowPosition(firstSelectedRow, secondSelectedRow); 
        firstSelectedRow = secondSelectedRow = -1; 
        return true; 
       } 
      } 
     } 
     return super.keyChar(ch, status, time); 
    } 

    protected boolean navigationMovement(int dx, int dy, int status, int time) { 
     invalidate(); 
     return super.navigationMovement(dx, dy, status, time); 
    } 

    protected boolean touchEvent(TouchEvent message) { 
     int eventCode = message.getEvent(); 

     // Get the screen coordinates of the touch event 
     touchX = message.getX(1); 
     touchY = message.getY(1)+getVerticalScroll(); 


     if(eventCode == TouchEvent.DOWN) { 
      mouseDownY = touchY; 
      mouseDownRowIndex = indexOfRowAt(mouseDownY); 
      showShadow = true; 

      invalidate(); 
      return true; 
     }   
     else if(eventCode == TouchEvent.UP) { 
      showShadow = false; 
      mouseUpY = touchY; 
      mouseUpRowIndex = indexOfRowAt(mouseUpY); 
      if(mouseDownRowIndex != mouseUpRowIndex) { 
       changeRowPosition(mouseDownRowIndex, mouseUpRowIndex); 
       mouseDownRowIndex = mouseUpRowIndex = -1; 
       invalidate(); 
       return true; 
      } 
      mouseDownRowIndex = mouseUpRowIndex = -1; 
      invalidate(); 
      return true; 
     } else if(eventCode == TouchEvent.MOVE) { 
      int index = indexOfRowAt(touchY-listRowHeight/2); 
      if(touchY-getVerticalScroll()<5) { 
       if(index > 0) { 
        index--; 
       } 
      } else if(touchY> (getPreferredHeight()-5)) { 
       if(index<listData.length-1) { 
        index++; 
       } 
      } 

      if(list.getSelectedIndex()!=index) 
       list.setSelectedIndex(index); 
      invalidate(); 
      return true; 
     } 
     return super.touchEvent(message); 
    } 

    protected void paint(Graphics graphics) { 
     // Save the original color and transparency values for the graphics 
     int preColor = graphics.getColor(); 
     int preAlpha = graphics.getGlobalAlpha(); 

     if(firstSelectedRow!=-1) { 
      int y = firstSelectedRow*listRowHeight; 
      graphics.setColor(0x808080); 
      graphics.fillRect(0, y, getWidth(), listRowHeight); 
     } 

     // Reset the previous color and transparency values for this graphics 
     graphics.setColor(preColor); 
     graphics.setGlobalAlpha(preAlpha) ; 

     super.paint(graphics); 

     if(firstSelectedRow != -1) { 
      int index = list.getSelectedIndex();    
      int y = index*listRowHeight; 
      String shadowText = listData[firstSelectedRow].toString(); 
      Font preFont = graphics.getFont(); 
      Font smallFont = preFont.derive(Font.BOLD, preFont.getHeight()-5); 
      y += (listRowHeight-smallFont.getHeight())/2; 
      graphics.setFont(smallFont); 
      int shadowTextLength = smallFont.getAdvance(shadowText); 
      graphics.setColor(0xE0E0E0); 
      graphics.setGlobalAlpha(100) ; 
      graphics.fillRoundRect(getWidth()/2-2, y, shadowTextLength+4, smallFont.getHeight(), 10, 10); 
      graphics.setColor(0x303030); 
      graphics.setGlobalAlpha(170) ; 
      graphics.drawText(shadowText, getWidth()/2, y); 
      graphics.setFont(preFont); 
     } 

     // Drawing the first selected SHADOW TEXT 
     if(showShadow && mouseDownRowIndex != -1) { 
      String shadowText = listData[mouseDownRowIndex].toString(); 
      Font preFont = graphics.getFont(); 
      Font smallFont = preFont.derive(Font.BOLD, preFont.getHeight()-5); 
      graphics.setFont(smallFont); 
      int shadowTextLength = smallFont.getAdvance(shadowText); 
      graphics.setColor(0xE0E0E0); 
      graphics.setGlobalAlpha(100) ; 
      graphics.fillRoundRect(touchX+10, touchY-smallFont.getHeight()/2, shadowTextLength, smallFont.getHeight(), 10, 10); 
      graphics.setColor(0x303030); 
      graphics.setGlobalAlpha(170) ; 
      graphics.drawText(shadowText, touchX+10, touchY-smallFont.getHeight()/2); 
      graphics.setFont(preFont); 
     } 

     // Drawing the VERTICAL SCROLLBAR 
     graphics.setColor(0x606060); 
     graphics.drawLine(getWidth()-18, getVerticalScroll(), getWidth()-18,getVerticalScroll()+getHeight()); 
     graphics.drawLine(getWidth()-17, getVerticalScroll(), getWidth()-17,getVerticalScroll()+getHeight()); 
     graphics.drawLine(getWidth()-16, getVerticalScroll(), getWidth()-16,getVerticalScroll()+getHeight()); 
     int listTotalHeight = listRowHeight * (listData.length+5); 
     int y = list.getSelectedIndex()*listRowHeight ; 
     int yScrollPosition = (int)Math.floor(((y*getHeight()*1.0)/listTotalHeight*1.0)); 
     graphics.fillRoundRect((getWidth()-17)-4, getVerticalScroll()+yScrollPosition, 8, listRowHeight, 2, 2); 
    } 
}