Question

我在Blackberry中创建了一个表模型适配器。（ ** 这是我正在做的样本 ****）我添加了按钮字段和两个字符串我将数据放入来自vector的字符串中。现在点击按钮我要删除按钮的行。数据从数据库中删除但是在单击按钮时不会从屏幕视图中删除。当我将Retrieve（）函数转换为调用更新的数据库并再次绘制Table模型适配器....它是在旧的下面添加新表....不刷新它。是否有任何解决方案可以在同一个表中显示刷新的数据。

    package mypackage;

   import java.util.Vector;
   import net.rim.device.api.system.Display;
   import net.rim.device.api.ui.Color;
   import net.rim.device.api.ui.Field;
   import net.rim.device.api.ui.FieldChangeListener;
   import net.rim.device.api.ui.Manager;
   import net.rim.device.api.ui.XYRect;
   import net.rim.device.api.ui.component.ButtonField;
   import net.rim.device.api.ui.component.LabelField;
   import net.rim.device.api.ui.component.table.DataTemplate;
   import net.rim.device.api.ui.component.table.TableController;
   import net.rim.device.api.ui.component.table.TableModelAdapter;
   import net.rim.device.api.ui.component.table.TableView;
   import net.rim.device.api.ui.component.table.TemplateColumnProperties;
   import net.rim.device.api.ui.component.table.TemplateRowProperties;
   import net.rim.device.api.ui.container.MainScreen;
   import net.rim.device.api.ui.decor.BackgroundFactory;

  public final class MyScreen extends MainScreen implements FieldChangeListener 
 {
private DeviceTableModelAdapter _tableModel;
private Vector _cities;
private static final int NUM_ROWS = 1;
    private static final int ROW_HEIGHT = 50;
    private static final int NUM_COLUMNS = 3;
    public ButtonField btn;

   public MyScreen(){
    super(Manager.NO_VERTICAL_SCROLL);

    _cities = new Vector();
    _tableModel = new DeviceTableModelAdapter();

    Vector sample =new Vector();
    sample.addElement("Newyork");
    sample.addElement("NewDelhi");
    sample.addElement("NewOrleans");
    int ik = 0;
       while(ik < sample.size())
       {
           String modelNumber = sample.elementAt(ik).toString();
           String modelName = "-Earth-";
           String ne = String.valueOf(ik);
           Object[] row = {modelName, modelNumber, ne};
           _tableModel.addRow(row);
           ik++;
       }

     TableView tableView = new TableView(_tableModel);
         tableView.setDataTemplateFocus(BackgroundFactory.createLinearGradientBackground(Color.WHITE, Color.WHITE, Color.BLUEVIOLET, Color.BLUEVIOLET));
     TableController tableController = new TableController(_tableModel, tableView);
     tableController.setFocusPolicy(TableController.ROW_FOCUS);
     tableView.setController(tableController);

     // Specify a simple data template for displaying 3 columns
     DataTemplate dataTemplate = new DataTemplate(tableView, NUM_ROWS, NUM_COLUMNS)
     {
         public Field[] getDataFields(int modelRowIndex)
         {
             Object[] data = (Object[]) (_tableModel.getRow(modelRowIndex));
             Field[] fields = {getButtonFieldObject((String)data[0]), new LabelField((String) data[1]), new LabelField((String) data[2])};
             return fields;
         }
     };

     dataTemplate.useFixedHeight(true);
     // Define regions and row height
     dataTemplate.setRowProperties(0, new TemplateRowProperties(ROW_HEIGHT));

     for(int i = 0; i < NUM_COLUMNS; i++)
     {
         dataTemplate.createRegion(new XYRect(i, 0, 1, 1));
         dataTemplate.setColumnProperties(i, new TemplateColumnProperties(Display.getWidth() / NUM_COLUMNS));
     }
     // Apply the template to the view

     tableView.setDataTemplate(dataTemplate);

     add(tableView);
}
public void fieldChanged(Field arg0, int arg1) {

/***    tableView.DeleteAll();  ****/

   /**** calling Class again to draw the table Modal Adapter again with updated value *******/

}
private final static class City
{
    private String _name;
    private String _region;
    private String _image;
    City(String name, String region, String image)
    {
        _name = name;
        _region = region;
        _image = image;
    }

    public String getName()
    {
        return _name;
    }
    public String getRegion()
    {
        return _region;
    }
    public String getImage()
    {
        return _image;
    }
}

 private class DeviceTableModelAdapter extends TableModelAdapter
    {
        public int getNumberOfRows()
        {
            return _cities.size();
        }
        public int getNumberOfColumns()
        {
            return NUM_COLUMNS;
        }
        protected boolean doAddRow(Object row)
        {
            Object[] arrayRow = (Object[]) row;
            _cities.addElement(new City((String) arrayRow[0], (String) arrayRow[1], (String) arrayRow[2]));
            return true;
        }
        protected Object doGetRow(int index)
        {
            City city = (City) _cities.elementAt(index);

            Object[] row = {city.getImage(), city.getRegion(), city.getName()};

            return row;

        }

    }
 public ButtonField getButtonFieldObject(String arg){

     btn = new ButtonField(arg,ButtonField.CONSUME_CLICK);
     btn.setChangeListener(this);
     return btn;
 }
     }

Answer 1

您必须考虑的是Blackberry表UI遵循MVC设计模式。所以这意味着数据在模型中更新。

例如：

Object yes = (Object)"Yes";
// gets the Model attached to this View
TableModel tm = (TableModel)view.getModel();
// updates the data attached to the row 
tm.setElement(rowIndex, columnIndex, yes); 
tm.modelReset();

从中删除记录时刷新表模型适配器：Blackberry

1 个答案: