Question

我想自定义树视图左侧显示的（+）符号可能吗我想把图像放在那个地方

我试图定制和搜索论坛也是黑莓论坛，其中一个人说不可能，但然后
我得到了一个链接，如下所示，这可能是

http://supportforums.blackberry.com/t5/Java-Development/Custom-TreeField/td-p/354901

其中似乎缺少HardwareDevice类

任何人都可以使用链接或他们自己的任何其他答案来解释这个概念请指教？

Answer 1

[ 更新 ]如果您想 CUSTOMIZE {{3}的每一行的（+） - 符号和其他属性} 而不是编写自己的树字段 ，然后您可以尝试重写TreeField drawTreeItem方法，如下所示：

import net.rim.device.api.system.Bitmap;
import net.rim.device.api.system.Display;
import net.rim.device.api.ui.Field;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.component.LabelField;
import net.rim.device.api.ui.component.TreeField;
import net.rim.device.api.ui.component.TreeFieldCallback;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.container.VerticalFieldManager;

public class TreeDemo extends MainScreen {
    int parent[] = {1,2,3,4,5,6,7,8,9};
    int child[][] = new int [10][10];
    int child_child[][][] = new int [10][10][10];

    int rowHeight = 27;

    CustomTreeFieldCallback treeCallback = new CustomTreeFieldCallback();
    VerticalFieldManager vm = new VerticalFieldManager(Field.FOCUSABLE | VERTICAL_SCROLL | VERTICAL_SCROLLBAR);
    TreeField myTree = new TreeField(treeCallback, Field.FOCUSABLE);

    public TreeDemo() {
        vm.add(new LabelField("Table:"));
        myTree.setRowHeight(rowHeight);
        myTree.setIndentWidth(15);
        myTree.setDefaultExpanded(false);
        for(int i = parent.length-1; i >= 0 ; i--) {
            parent[i] = myTree.addChildNode(0, "Parent_" + (i+1));
            child[i] = new int[4];
            for(int j = child[i].length-1; j >=0 ; j--) {
                child[i][j] = myTree.addChildNode(parent[i], "Child_"+ (i+1) + "_" + (j+1));
                child_child[i][j] = new int[3];
                for(int k = child_child[i][j].length-1; k >= 0 ; k--) {
                    child_child[i][j][k] = myTree.addChildNode(child[i][j], "Child_of_Child_"+ (i+1) + "_" + (j+1)+ "_" + (k+1));
                }
            }
        }
        vm.add(myTree);
        add(vm);
    }

    private class CustomTreeFieldCallback implements TreeFieldCallback {

        public void drawTreeItem(TreeField treeField, Graphics graphics, int node,
                int y, int width, int indent) {
            // TODO Auto-generated method stub
            String string = (String) treeField.getCookie(node);
            int preservedColor = graphics.getColor();

            if(treeField.getCurrentNode() == node) {
                graphics.setColor(0x0CCCC0);
            } else {
                graphics.setColor(0x404040);
            }
            graphics.fillRect(0, y, Display.getWidth(), treeField.getRowHeight());

            Bitmap iconImage;
            int iconImageWidth = 0;
            indent -= 20; // decrease the extra indentation for all nodes.
            if(treeField.getFirstChild(node) != -1){ // if the node is not a leaf node
                if(treeField.getExpanded(node)) {
                    iconImage = Bitmap.getBitmapResource("icon_arrow_down.png");
                    iconImageWidth = iconImage.getWidth();
                } else {
                    iconImage = Bitmap.getBitmapResource("icon_arrow_right.png");
                    iconImageWidth = iconImage.getWidth();
                }
                graphics.drawBitmap(indent, y, indent+iconImageWidth, treeField.getRowHeight(), iconImage, 0, 0);
            }

            if( treeField.getCurrentNode() == node ) {
                graphics.setColor(0x404040);            
            } else {
                graphics.setColor(0x0CCCC0);
            }
            graphics.drawText(string, indent+iconImageWidth, y);

            graphics.setColor(preservedColor);
        }

    }
}

Customizing TreeField in BlackBerry

Answer 2

尝试使用以下代码进行带图像的自定义treeField

import net.rim.device.api.system.Bitmap;
import net.rim.device.api.system.Display;
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.UiApplication;
import net.rim.device.api.ui.component.BitmapField;
import net.rim.device.api.ui.component.LabelField;
import net.rim.device.api.ui.component.SeparatorField;
import net.rim.device.api.ui.container.HorizontalFieldManager;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.container.VerticalFieldManager;

/**
 * A class extending the MainScreen class, which provides default standard
 * behavior for BlackBerry GUI applications.
 */
public final class MyScreen extends MainScreen implements FieldChangeListener
{
    /**
     * Creates a new MyScreen object
     */
    private VerticalFieldManager main_manager;
    private HorizontalFieldManager parentNodes;
    private LabelField parent_lables[];
    private Bitmap bitmap,upbitmap;
    private BitmapField bitmap_field[];
    private VerticalFieldManager submanager[];
    private int sizeOfParentNodes=3;
    private int sizeOfChildNodes=5;
    private static boolean flag[];

    public MyScreen()
    {        
        // Set the displayed title of the screen       
        bitmap=Bitmap.getBitmapResource("arrow.png");
        upbitmap=Bitmap.getBitmapResource("uparrow.png");
        main_manager=new VerticalFieldManager(Manager.VERTICAL_SCROLL|VERTICAL_SCROLLBAR){
            protected void sublayout(int maxWidth, int maxHeight) {
                super.sublayout(Display.getWidth(), Display.getHeight());
                setExtent(Display.getWidth(), Display.getHeight());
            };
        };
        parent_lables=new LabelField[sizeOfParentNodes];
        flag=new boolean[sizeOfParentNodes];
        submanager=new VerticalFieldManager[sizeOfParentNodes];
        bitmap_field=new BitmapField[sizeOfParentNodes];
        for(int i=0;i<sizeOfParentNodes;i++)
        {
            submanager[i]=new VerticalFieldManager();
            updateGUI(i);
            main_manager.add(submanager[i]);
        }

        add(main_manager);


    }
    public void fieldChanged(Field field, int context) {
        // TODO Auto-generated method stub
        synchronized (UiApplication.getEventLock()) {
            for(int i=0;i<sizeOfParentNodes;i++)
            {   if(field==parent_lables[i])
                {
                    if(flag[i]==true){
                        flag[i]=false;
                        submanager[i].deleteAll();
                        updateGUI(i);
                        parent_lables[i].setFocus();
                    }else{
                        flag[i]=true;
                        bitmap_field[i].setBitmap(upbitmap);
                        for(int j=0;j<sizeOfChildNodes;j++)
                        {
                            submanager[i].add(new LabelField("        Child :"+i+","+j,Field.FOCUSABLE));
                            submanager[i].add(new SeparatorField());
                        }
                        submanager[i].invalidate();
                    }

                }
            }
        }


    }
    public void updateGUI(int index)
    {
        parentNodes=new HorizontalFieldManager(USE_ALL_WIDTH);
        bitmap_field[index]=new BitmapField(bitmap);

        parentNodes.add(bitmap_field[index]);
        parent_lables[index]=new LabelField("Day"+index,Field.FOCUSABLE){
            protected boolean navigationClick(int status, int time) {
                fieldChangeNotify(1);
                return true;
            };
        };
        parentNodes.add(parent_lables[index]);
        parent_lables[index].setChangeListener(this);
        submanager[index].add(parentNodes);
    }
}

你可以输出

enter image description here

自定义Blackberry Treefield

2 个答案: