尝试在 BlackBerry 6 上实现图片库时,我遇到了这个烦人的问题。
一切正常,但是当焦点从顶部按钮变为屏幕下方的图片时,图像似乎出现故障并且无法正确绘制自己。请参阅下面的图片以获取示例:
(焦点在屏幕顶部(未显示))
(焦点现在在左下角的图像上,请注意,由于未知原因,顶部的图像现在是空白的)
无论我在缩略图库中添加多少图片,都会发生这种情况。
现在这是我的代码,(其中一部分与缩略图的绘制有关)
public ProductImage(String productName){
super(VERTICAL_SCROLL|VERTICAL_SCROLLBAR);
currentProduct = productName;
createGUI();
}
public void createGUI(){
deleteAll();
try{
Storage.loadPicture();
}catch(NullPointerException e){
e.printStackTrace();
}
this.setTitle(new LabelField(_resources.getString(PRODUCT_IMAGE), Field.FIELD_HCENTER));
if(ToolbarManager.isToolbarSupported())
{
Toolbar tb = new Toolbar();
setToolbar(tb.createToolBar());
}
else{
Toolbar tb = new Toolbar();
add(tb.createNavBar());
}
picVector = Storage.getPicture(currentProduct);
EncodedImage enc = EncodedImage.getEncodedImageResource("camera.png");
EncodedImage sizeEnc = ImageResizer.sizeImage(enc, Display.getHeight(), Display.getHeight());
takenPicture = new BitmapField(enc.getBitmap());
vfMain = new VerticalFieldManager();
vfMain.add(logo);
vfMain.add(new SeparatorField());
add(vfMain);
prepareBmpFields();
}
private void prepareBmpFields() {
System.out.println("This is the vector size: " + picVector.getPicVector().size());
LayoutManager manager = new LayoutManager();
FieldChangeListener itemListener = new ButtonListener();
mBmpFields = new ImageButtonField[picVector.getPicVector().size()];
for (int i = 0; i < picVector.getPicVector().size(); i++) {
/*EncodedImage image = EncodedImage
.getEncodedImageResource((String)imageVector.elementAt(i));*/
byte[] data = getData((String)picVector.getPicVector().elementAt(i));
//Encode and Resize image
EncodedImage eImage = EncodedImage.createEncodedImage(data,0,data.length);
eImage = ImageResizer.resizeImage(eImage, mImgWidth, mImgHeight);
ImageButtonField currentImage = new ImageButtonField(eImage.getBitmap());
currentImage.setAssociatedPath((String)picVector.getPicVector().elementAt(i));
mBmpFields[i] = currentImage;
mBmpFields[i].setChangeListener(itemListener);
manager.add(mBmpFields[i]);
}
vfMain.add(manager);
}
private class LayoutManager extends VerticalFieldManager {
public LayoutManager() {
super(VERTICAL_SCROLL | VERTICAL_SCROLLBAR);
}
protected void sublayout(int width, int height) {
int columns = mScrWidth / (mImgWidth + 2 * mImgMargin);
int scrWidth = Display.getWidth();
int rows = mBmpFields.length / columns
+ (mBmpFields.length % columns > 0 ? 1 : 0);
int counter = 0;
for (int i = 0; i < rows; i++) {
for (int j = 0; j < columns; j++) {
int posX = j * (mImgWidth + 2 * mImgMargin) + mImgMargin;
int posY = i * (mImgHeight + 2 * mImgMargin) + mImgMargin;
if(mBmpFields.length > counter){
Field field = mBmpFields[counter];
layoutChild(field, mImgWidth, mImgHeight);
setPositionChild(field, posX, posY);
counter++;
};
}
}
if(Display.getWidth() < Display.getHeight()){
setExtent(mScrWidth, (int)(mScrHeight*1.25));
}
else{
setExtent(mScrWidth, (int)(mScrHeight*2));
}
}
public int getPreferredWidth() {
return mScrWidth;
}
public int getPreferredHeight() {
return mScrHeight;
}
}
}
我已经删除了许多不相关的代码部分,但需要的代码在那里。
有谁知道是什么导致了这个问题?谢谢你的帮助!
编辑:根据要求,这是我对 ImageButtonField 类的实现:
import net.rim.device.api.system.Bitmap;
import net.rim.device.api.system.Characters;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.component.BitmapField;
public class ImageButtonField extends BitmapField{
String associatedPath ="";
BitmapField image2;
public ImageButtonField(Bitmap image) {
super(image);
}
public void setAssociatedPath(String path){
associatedPath = path;
}
public String getAssociatedPath(){
return associatedPath;
}
public boolean isFocusable() {
return true;
}
protected void applyTheme(Graphics arg0, boolean arg1) {
}
protected void drawFocus(Graphics graphics, boolean on) {
}
protected void onFocus(int direction) {
// only change appearance if this button is enabled (aka editable)
if (isEditable()) {
invalidate(); // repaint
}
super.onFocus(direction);
}
public void onUnfocus() {
invalidate(); // repaint
super.onUnfocus();
}
protected boolean navigationClick(int status, int time) {
fieldChangeNotify(0);
return true;
}
protected boolean trackwheelClick(int status, int time) {
fieldChangeNotify(0);
return true;
}
protected void paint(Graphics graphics) {
super.paint(graphics);
if (isFocus()) {
graphics.setGlobalAlpha(128);
graphics.setColor(0x888888);
graphics.fillRect(0, 0, getWidth(), getHeight());
}else{
graphics.setGlobalAlpha(0);
graphics.setColor(0x000000);
graphics.fillRect(0, 0, getWidth(), getHeight());
//graphics.drawBitmap(0, 0, getWidth(), getHeight(), image2.getB, 0, 0);
}
}
protected boolean keyChar(char character, int status, int time) {
if(Characters.ENTER == character || Characters.SPACE == character) {
fieldChangeNotify(0);
return true;
}
return super.keyChar(character, status, time);
}
}