如何在BlackBerry中自定义ListField？

Question

我想在BlackBerry中自定义一个ListField，它可以列出一行中的图像和文本。

如何做到这一点？

Answer 1

screenshot http://img10.imageshack.us/img10/1410/listfield.jpg
尝试是这样的：

class TaskListField extends ListField implements ListFieldCallback { 
private Vector rows; 
private Bitmap p1; 
private Bitmap p2; 
private Bitmap p3; 

public TaskListField() { 
    super(0, ListField.MULTI_SELECT); 
    setRowHeight(80); 
    setEmptyString("Hooray, no tasks here!", DrawStyle.HCENTER); 
    setCallback(this); 

    p1 = Bitmap.getBitmapResource("1.png"); 
    p2 = Bitmap.getBitmapResource("2.png"); 
    p3 = Bitmap.getBitmapResource("3.png"); 

    rows = new Vector(); 

    for (int x = 0; x < 10; x++) { 
    TableRowManager row = new TableRowManager(); 

    // SET THE PRIORITY BITMAP FIELD 
    // if high priority, display p1 bitmap 
    if (x % 2 == 0) { 
    row.add(new BitmapField(p1)); 
    } 
    // if priority is 2, set p2 bitmap 
    else if (x % 3 == 0) { 
    row.add(new BitmapField(p2)); 
    } 
    // if priority is 3, set p3 bitmap 
    else { 
    row.add(new BitmapField(p3)); 
    } 

    // SET THE TASK NAME LABELFIELD 
    // if overdue, bold/underline 
    LabelField task = new LabelField("Task #" + String.valueOf(x), 
    DrawStyle.ELLIPSIS); 
    // if due today, bold 
    if (x % 2 == 0) { 
    task.setFont(Font.getDefault().derive(
     Font.BOLD | Font.UNDERLINED)); 
    System.out.println("OVERDUE"); 
    } else { 
    task.setFont(Font.getDefault().derive(Font.BOLD)); 
    System.out.println("TODAY"); 
    } 

    row.add(task); 

    // SET THE LIST NAME 
    row.add(new LabelField("List Name #" + String.valueOf(x), 
    DrawStyle.ELLIPSIS) { 
    protected void paint(Graphics graphics) { 
    graphics.setColor(0x00878787); 
    super.paint(graphics); 
    } 
    }); 

    // SET THE DUE DATE/TIME 
    row.add(new LabelField("Due Date #" + String.valueOf(x), 
    DrawStyle.ELLIPSIS | LabelField.USE_ALL_WIDTH 
     | DrawStyle.RIGHT) { 
    protected void paint(Graphics graphics) { 
    graphics.setColor(0x00878787); 
    super.paint(graphics); 
    } 
    }); 
    rows.addElement(row); 
    } 
    setSize(rows.size()); 

} 

// ListFieldCallback Implementation 
public void drawListRow(ListField listField, Graphics g, int index, int y, 
    int width) { 
    TaskListField list = (TaskListField) listField; 
    TableRowManager rowManager = (TableRowManager) list.rows 
    .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(); 

    // start with the Bitmap Field of the priority icon 
    Field field = getField(0); 
    layoutChild(field, 32, 32); 
    setPositionChild(field, 0, 0); 

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

    // set the list name label field 
    field = getField(2); 
    layoutChild(field, 150, fontHeight + 1); 
    setPositionChild(field, 34, fontHeight + 6); 

    // set the due time name label field 
    field = getField(3); 
    layoutChild(field, 150, fontHeight + 1); 
    setPositionChild(field, preferredWidth - 152, fontHeight + 6); 

    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; 
} 

} 

从 rtm4bb - A BlackBerry Client for Remember the Milk

见代码：

Answer 2

不知道你想要做什么的更多细节，我建议看一看BlackBerry开发环境附带的一些示例应用程序。几个应用程序，如Contacts.java和PhoneApiDemo.java有一个ListField和ListFieldCallback实现。

Answer 3

与黑莓的Java SDK 6.0开始，你可以使用一个RichList：

使用富豪榜显示包含在左侧，图像旁边的标签和图像下方的可选 描述列表的可选 图像的项目清单和标签

RichList list = new RichList(mainManager, true, 2, 1); 

list.add(new Object[] {bitmap1, "Device 1", 
         "BlackBerry Smartphone 9500", 
         "Description of Device 1."}); 
list.add(new Object[] {bitmap2, "Device 2", 
         "BlackBerry Smartphome 9000", 
         "Description of Device 2."});