BlackBerry - 在方向更改后重绘我的标题栏

Question

我正在编写一个使用自定义标题栏的BlackBerry应用程序。我的应用程序使用图像，而不是使用基于文本的标题栏。

一旦设备的方向（如BlackBerry Storm或Torch）从纵向更改为横向，我无法重新绘制此标题栏。请参阅下面我的titleBar类的代码。

任何帮助将不胜感激！谢谢！

import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.component.BitmapField;
import net.rim.device.api.system.Bitmap;
import net.rim.device.api.ui.Color;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.*;
import net.rim.device.api.ui.component.*;
import net.rim.device.api.ui.container.*;
import net.rim.device.api.system.*;

/**
 * Title Bar
 */

public class TitleBar extends Field implements DrawStyle
{
    private int fieldWidth;
    private int fieldHeight;
    private int fontColour;
    private int backgroundColor;

    private Bitmap bgImage = Bitmap.getBitmapResource("bgtitle.png");
    private Bitmap titleImage =  Bitmap.getBitmapResource("logotitle.png");
    private static final int BACKGROUND_COLOR = 0x00000000;


    public TitleBar() 
    {
        super(Field.NON_FOCUSABLE);
        fieldHeight = titleImage.getHeight();
        fieldWidth = Display.getWidth();

        //background color is black
        backgroundColor = BACKGROUND_COLOR;        
    }

    public void setBackgroundColour(int _backgroundColour)
    {
        backgroundColor = _backgroundColour;
        invalidate();
    }

    protected void layout(int width, int height) 
    {
        setExtent(getPreferredWidth(), getPreferredHeight());
    }

    public int getPreferredWidth() 
    {
        return fieldWidth;
    }

    public int getPreferredHeight() 
    {
        return fieldHeight;
    }

    protected void paint(Graphics graphics) 
    {

        int w = this.getPreferredWidth();
        int h = this.getPreferredHeight();

        int width_of_bg = 10;
        int paint_position = 0;

        int screen_width = Display.getWidth();
        while(paint_position<screen_width){
            graphics.drawBitmap(paint_position, 0, w, h, bgImage, 0, 0);
            paint_position += width_of_bg;
        }

        int marginX = (w- titleImage.getWidth() ) / 2 ; 
        graphics.drawBitmap(marginX, 0, w, h, titleImage, 0, 0);
    }
}

Answer 1

解决了！

这是因为我在构造函数中获得了宽度。当设备重新定向时，我将检索在构造函数中获取的保存值。

这是固定代码：

import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.component.BitmapField;
import net.rim.device.api.system.Bitmap;
import net.rim.device.api.ui.Color;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.*;
import net.rim.device.api.ui.component.*;
import net.rim.device.api.ui.container.*;
import net.rim.device.api.system.*;

/**
 * Title Bar
 */

public class TitleBar extends Field implements DrawStyle
{
    private int fieldWidth;
    private int fieldHeight;
    private int fontColour;
    private int backgroundColor;

    private Bitmap bgImage = Bitmap.getBitmapResource("bgtitle.png");
    private Bitmap titleImage =  Bitmap.getBitmapResource("logotitle.png");
    private static final int BACKGROUND_COLOR = 0x00000000;


    public TitleBar() 
    {
        super(Field.NON_FOCUSABLE);
        fieldHeight = titleImage.getHeight();
        fieldWidth = Display.getWidth();

        //background color is black
        backgroundColor = BACKGROUND_COLOR;        
    }

    public void setBackgroundColour(int _backgroundColour)
    {
        backgroundColor = _backgroundColour;
        invalidate();
    }

    protected void layout(int width, int height) 
    {
        setExtent(getPreferredWidth(), getPreferredHeight());
    }

    public int getPreferredWidth() 
    {
        return Display.getWidth();
    }

    public int getPreferredHeight() 
    {
        return fieldHeight;
    }

    protected void paint(Graphics graphics) 
    {

        int w = this.getPreferredWidth();
        int h = this.getPreferredHeight();

        int width_of_bg = 10;
        int paint_position = 0;

        while(paint_position<w){
            graphics.drawBitmap(paint_position, 0, w, h, bgImage, 0, 0);
            paint_position += width_of_bg;
        }

        int marginX = (w- titleImage.getWidth() ) / 2 ; 
        graphics.drawBitmap(marginX, 0, w, h, titleImage, 0, 0);
    }
}