在 Listfield 中无法查看黑莓中的字段

Question

我已尝试此链接How to customize a ListField in BlackBerry? 为每个列表行创建具有三个标签字段的 ListField。但我无法看到列表字段项目。但我可以说添加了列表字段。因为在导航上单击我可以得到列表字段的选定索引。请任何人帮助我做错了。我尝试过的代码是......

public class InboxWithOutCheckboxeslistfield extends ListField implements ListFieldCallback  {
    private Vector rows;
    private TableRowManager row ;
    private LabelField UserName,Message,Timestamp;


    /**
     * Creates a new MyScreen object
     */
     public InboxWithOutCheckboxeslistfield() {
        // TODO Auto-generated constructor stub

        super(0, ListField.MULTI_SELECT);
        setRowHeight(80);
        setCallback(this);
        rows = new Vector();
        for (int x = 0; x < 10; x++) {
            row = new TableRowManager();
            UserName = new LabelField("" + String.valueOf(x),
                    DrawStyle.ELLIPSIS | LabelField.USE_ALL_WIDTH
                    | DrawStyle.LEFT);
            UserName.setText("name");
            row.add(UserName);
            Message = new LabelField("" + String.valueOf(x),
                    DrawStyle.ELLIPSIS | LabelField.USE_ALL_WIDTH
                    | DrawStyle.RIGHT);
            Message.setText("hai");
            row.add(Message);
            Timestamp = new LabelField("" + String.valueOf(x),
                    DrawStyle.ELLIPSIS | LabelField.USE_ALL_WIDTH
                    | DrawStyle.RIGHT);
            Timestamp.setText("hai");
            row.add(Timestamp);
            rows.addElement(row);

        }
        setSize(rows.size());


    }

    public void drawListRow(ListField listField, Graphics graphics, int index,
            int y, int width) {
        // TODO Auto-generated method stub

        InboxWithOutCheckboxeslistfield list = (InboxWithOutCheckboxeslistfield) listField;


        TableRowManager rowManager = (TableRowManager) list.rows.elementAt(index);
        rowManager.drawRow(graphics, 0, y, width, list.getRowHeight());

    }

    public Object get(ListField listField, int index) {
        // TODO Auto-generated method stub
        return null;
    }

    public int getPreferredWidth(ListField listField) {
        // TODO Auto-generated method stub
        return 0;
    }

    public int indexOfList(ListField listField, String prefix, int start) {
        // TODO Auto-generated method stub
        return 0;
    }


    private class TableRowManager extends Manager {

        protected TableRowManager(){super(0);
        // TODO Auto-generated constructor stub}
        }

        public void drawRow(Graphics graphics, int i, int y, int width,
                int rowHeight) {
            // TODO Auto-generated method stub
            // Arrange the cell fields within this row manager.
            layout(width, rowHeight);

            // Place this row manager within its enclosing list.
            setPosition(i, y);

            // Apply a translating/clipping transformation to the graphics
            // context so that this row paints in the right area.
            graphics.pushRegion(getExtent());

            // Paint this manager's controlled fields.
            subpaint(graphics);

            graphics.setColor(0x00CACACA);
            graphics.drawLine(0, 0, getPreferredWidth(), 0);

            // Restore the graphics context.
            graphics.popContext();

        }

        protected void sublayout(int width, int height) {
            // TODO Auto-generated method stub
            // set the size and position of each field.
            int fontHeight = Font.getDefault().getHeight();
            int preferredWidth = getPreferredWidth();

            Field field = getField(0);

            layoutChild(field, preferredWidth - 16, fontHeight + 1);
            setPositionChild(field, 34, 3);
            // set the list name label field
            field = getField(1);
            layoutChild(field, 150, fontHeight + 1);
            setPositionChild(field, 34, fontHeight + 6);

            // set the due time name label field
            field = getField(2);
            layoutChild(field, 150, fontHeight + 1);
            setPositionChild(field, preferredWidth - 152, fontHeight + 6);

            setExtent(getPreferredWidth(), getPreferredHeight());

        }
        // The preferred width of a row is defined by the list renderer.  
        public int getPreferredWidth()  
        {       

            return getWidth();        
        } 
        // The preferred height of a row is the "row height" as defined in the  
        // enclosing list.      
        public int getPreferredHeight()     
        { 
            return getHeight();       
        } 

    }
    protected boolean navigationClick(int status, int time) {
        int index1 = getSelectedIndex();
        System.out.println("The Clikced item is:"+index1);
        return true;
    }
}

主屏类是

public class InboxWithOutCheckboxes extends MainScreen{

    private InboxWithOutCheckboxeslistfield inboxWithOutCheckboxeslistfield;

    public InboxWithOutCheckboxes(){
        super();
        inboxWithOutCheckboxeslistfield = new InboxWithOutCheckboxeslistfield();
         add(inboxWithOutCheckboxeslistfield);     
         add(new SeparatorField()); 
    }

}

Answer 1

试试这个代码 -

在主屏幕上添加列表-

InboxWithOutCheckboxeslistfield InboxWithOutCheckboxeslistfield = new InboxWithOutCheckboxeslistfield ();
add(InboxWithOutCheckboxeslistfield );
add(new SeparatorField());

列表的点击事件监听器 -

protected boolean navigationClick(int status, int time) {
    getValue();
    return true;
}
protected void getValue() {
Field f = getFieldWithFocus();

if (f instanceof ListField) {
    ListField l = (ListField) f;

    final int index = l.getSelectedIndex();

    FriendsRequestObject _contactslist = (FriendsRequestObject) FriendsRequest_fields.vector.elementAt(index);
    final String _name = _contactslist.getSender_name();
    final String _id = _contactslist.getSender_id();
    //Dialog.alert(_name);

    Application.getApplication().invokeLater(new Runnable() {
        public void run() {
            Dialog.alert(_name);
        }
    }); 
    // Dialog.alert("The selected element is: "+Integer.toString(l.getSelectedIndex()));
}
}





import java.util.Vector;
import net.rim.device.api.ui.Color;
import net.rim.device.api.ui.DrawStyle;
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.Manager;
import net.rim.device.api.ui.component.LabelField;
import net.rim.device.api.ui.component.ListField;
import net.rim.device.api.ui.component.ListFieldCallback;

class InboxWithOutCheckboxeslistfield extends ListField implements ListFieldCallback {

private Vector contacts;
static Vector vector = new Vector();

private int contactslist_size = 0;

private String name_ = "", id_="", status_="";

public InboxWithOutCheckboxeslistfield () {
    super(0, ListField.MULTI_SELECT);
    setRowHeight(60);
    setEmptyString("Empty List", DrawStyle.HCENTER);
    setCallback(this);

    contacts = new Vector();

    vector.addElement(new FriendsRequestObject("1", "hai1", ""));
    vector.addElement(new FriendsRequestObject("2", "hai2", ""));
    vector.addElement(new FriendsRequestObject("3", "hai3", ""));
    vector.addElement(new FriendsRequestObject("4", "hai4", ""));

    contactslist_size = vector.size();

    for (int x = 0; x < contactslist_size; x++) {

        FriendsRequestObject b = (FriendsRequestObject) vector.elementAt(x);

        id_ = b.getSender_id().toString();
        name_ = b.getSender_name().toString();
        status_ = b.getimage().toString();



        TableRowManager row = new TableRowManager() {
            public void paint(Graphics g) {
                 g.setBackgroundColor(Color.BLACK);
                g.fillRect(0, 0, getWidth(), getHeight());
                 g.setColor(Color.BLACK);
                 g.clear();
                 super.paint(g);
            }
        };

        LabelField name1 = new LabelField(id_, DrawStyle.ELLIPSIS);
        name1.setFont(Font.getDefault().derive(Font.PLAIN));
        row.add(name1);

        LabelField name = new LabelField(name_, DrawStyle.ELLIPSIS);
        name.setFont(Font.getDefault().derive(Font.PLAIN));
        row.add(name);

        // add to the table
        contacts.addElement(row);
    }

    setSize(contacts.size());
}

// ListFieldCallback Implementation
public void drawListRow(ListField listField, Graphics g, int index, int y, int width) {
    InboxWithOutCheckboxeslistfield  list = (InboxWithOutCheckboxeslistfield ) listField;
    TableRowManager rowManager = (TableRowManager) list.contacts.elementAt(index);
    rowManager.drawRow(g, 0, y, width, list.getRowHeight());
}

private class TableRowManager extends Manager {
    public TableRowManager() {
        super(0);
    }

    // Causes the fields within this row manager to be layed out then
    // painted.
    public void drawRow(Graphics g, int x, int y, int width, int height) {
        // Arrange the cell fields within this row manager.
        layout(width, height);

        // Place this row manager within its enclosing list.
        setPosition(x, y);

        // Apply a translating/clipping transformation to the graphics
        // context so that this row paints in the right area.
        g.pushRegion(getExtent());

        // Paint this manager's controlled fields.
        subpaint(g);

        g.setColor(0x00CACACA);
        g.drawLine(0, 0, getPreferredWidth(), 0);

        // Restore the graphics context.
        g.popContext();
    }

    // Arrages this manager's controlled fields from left to right within
    // the enclosing table's columns.
    protected void sublayout(int width, int height) {
        // set the size and position of each field.
        int fontHeight = Font.getDefault().getHeight();
        int preferredWidth = getPreferredWidth();

        /* positioning of fields in list */
        // Status
        Field field = getField(0);
        layoutChild(field, preferredWidth, 50);
        setPositionChild(field, 10, 5);


        // Name
         field = getField(1);
         layoutChild(field, 150, fontHeight + 1);   
        //setPositionChild(field, 1, 2);
        setPositionChild(field, 80, fontHeight );
        setExtent(preferredWidth, getPreferredHeight());
                }

    // The preferred width of a row is defined by the list renderer.
    public int getPreferredWidth() {
        return Graphics.getScreenWidth();
    }

    // The preferred height of a row is the "row height" as defined in the
    // enclosing list.
    public int getPreferredHeight() {
        return getRowHeight();
    }

}

public Object get(ListField listField, int index) {
    return null;
}

public int getPreferredWidth(ListField listField) {
    return 0;
}

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

}

FriendsRequestObject 如下 -

public class FriendsRequestObject {

private String sender_id;
private String sender_name;
private String image;

public FriendsRequestObject(String sender_id, String sender_name, String image){
    this.sender_id =  sender_id;
    this.sender_name =sender_name;
    this.image =image;
}



public String getimage() {
    return image;
}
public void setimage(String image) {
    this.image = image;
}

public String getSender_id() {
    return sender_id;
}
public void setSender_id(String sender_id) {
    this.sender_id = sender_id;
}

public String getSender_name() {
    return sender_name;
}
public void setSender_name(String sender_name) {
    this.sender_name = sender_name;
}

}

Answer 2

编辑TableRowManager 的实现。您需要更改getPreferredWidth() 和getPreferredHeight()。如果 sublayout() 方法执行没有提前完成，getWidth() 和 getHeight() 将返回错误值。

// The preferred width of a row is defined by the list renderer.
public int getPreferredWidth() {
    return Display.getWidth();
}

// The preferred height of a row is the "row height" as defined in the
// enclosing list.
public int getPreferredHeight() {
    return getRowHeight();
}