如何在BlackBerry中自定义ListField？

Question

我想在BlackBerry中自定义ListField，以便能够连续列出图像和文本。如何做到这一点？

Answer 1

尝试这样的事情：

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;

 }

}

Answer 2

从BlackBerry Java SDK 6.0开始，您可以使用RichList：

使用丰富列表显示项目列表，这些项目的左侧包含一个可选图像，该图像旁边的标签列表以及该图像和标签下方的可选描述

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."});