我创建了一个SliderField类，以便在我的BlackBerry应用程序中显示可拖动的滑块。滑块主要用于设置应用程序中位置更新的间隔（通过GPS）。该应用程序基于OS 5.0构建，因此未找到SliderField的API。问题 我面临的是，当移动滑块时，我需要增加标签中的整数值。例如，如果标签中的整数值为1并且用户移动滑块，则值应增加到5,10,15等。我不知道如何链接移动滑块以增加标签字段中的值。有人可以帮忙吗？我将SliderField对象添加到屏幕，如下所示：
Bitmap sliderBack = Bitmap.getBitmapResource( "progress51.png" );
Bitmap sliderFocus = Bitmap.getBitmapResource( "progress51.png" );
Bitmap sliderThumb = Bitmap.getBitmapResource( "butt.png" );
SliderField theSlider = new SliderField( sliderThumb, sliderBack, sliderFocus,20, 1, 1, 1 );
secondHFM.add(theSlider)
下面是我的SliderField类的代码。
public class SliderField extends Field
{
Bitmap _imageThumb;
Bitmap _imageSlider;
Bitmap _imageSliderLeft;
Bitmap _imageSliderCenter;
Bitmap _imageSliderRight;
Bitmap _imageSliderFocus;
Bitmap _imageSliderFocusLeft;
Bitmap _imageSliderFocusCenter;
Bitmap _imageSliderFocusRight;
private int _numStates;
private int _currentState;
private boolean _selected;
private int _xLeftBackMargin;
private int _xRightBackMargin;
private int _thumbWidth;
private int _thumbHeight;
private int _totalHeight;
private int _totalWidth;
private int _rop;
private int _backgroundColours[];
private int _backgroundSelectedColours[];
private int _defaultSelectColour = 0x977DED;
private int _defaultBackgroundColour = 0x000000;
private int _defaultHoverColour = 0x999999;
public SliderField( Bitmap thumb
, Bitmap sliderBackground
, int numStates
, int initialState
, int xLeftBackMargin
, int xRightBackMargin )
{
this( thumb, sliderBackground, sliderBackground, numStates, initialState, xLeftBackMargin, xRightBackMargin, FOCUSABLE );
}
public SliderField( Bitmap thumb
, Bitmap sliderBackground
, int numStates
, int initialState
, int xLeftBackMargin
, int xRightBackMargin
, long style )
{
this( thumb, sliderBackground, sliderBackground, numStates, initialState, xLeftBackMargin, xRightBackMargin, style );
}
public SliderField( Bitmap thumb
, Bitmap sliderBackground
, Bitmap sliderBackgroundFocus
, int numStates
, int initialState
, int xLeftBackMargin
, int xRightBackMargin )
{
this( thumb, sliderBackground, sliderBackgroundFocus, numStates, initialState, xLeftBackMargin, xRightBackMargin, FOCUSABLE );
}
public SliderField( Bitmap thumb
, Bitmap sliderBackground
, Bitmap sliderBackgroundFocus
, int numStates
, int initialState
, int xLeftBackMargin
, int xRightBackMargin
, long style )
{
super( style );
if( initialState > numStates || numStates < 2 ){
}
_imageThumb = thumb;
_imageSlider = sliderBackground;
_imageSliderFocus = sliderBackgroundFocus;
_numStates = numStates;
setState( initialState );
_xLeftBackMargin = xLeftBackMargin;
_xRightBackMargin = xRightBackMargin;
_rop = _imageSlider.hasAlpha() ? Graphics.ROP_SRC_ALPHA : Graphics.ROP_SRC_COPY;
_thumbWidth = thumb.getWidth();
_thumbHeight = thumb.getHeight();
initBitmaps();
}
public SliderField( Bitmap thumb
, Bitmap sliderBackground
, int numStates
, int initialState
, int xLeftBackMargin
, int xRightBackMargin
, int[] colours
, int[] selectColours )
{
this(thumb, sliderBackground, sliderBackground, numStates, initialState, xLeftBackMargin, xRightBackMargin, FOCUSABLE );
if( colours.length != numStates+1 ){
throw new IllegalArgumentException();
}
_backgroundColours = colours;
_backgroundSelectedColours = selectColours;
}
public void initBitmaps()
{
int height = _imageSlider.getHeight();
_imageSliderLeft = new Bitmap( _xLeftBackMargin, height );
_imageSliderCenter = new Bitmap( _imageSlider.getWidth() - _xRightBackMargin - _xLeftBackMargin, height);
_imageSliderRight = new Bitmap( _xRightBackMargin, height );
copy( _imageSlider, 0, 0, _xLeftBackMargin, height, _imageSliderLeft );
copy( _imageSlider, _xLeftBackMargin, 0, _imageSlider.getWidth() - _xRightBackMargin - _xLeftBackMargin, height, _imageSliderCenter);
copy( _imageSlider, _imageSlider.getWidth() - _xRightBackMargin, 0, _xRightBackMargin, height, _imageSliderRight);
_imageSliderFocusLeft = new Bitmap( _xLeftBackMargin, height );
_imageSliderFocusCenter = new Bitmap( _imageSlider.getWidth() - _xRightBackMargin - _xLeftBackMargin, height);
_imageSliderFocusRight = new Bitmap( _xRightBackMargin, height );
copy( _imageSliderFocus, 0, 0, _xLeftBackMargin, height, _imageSliderFocusLeft );
copy( _imageSliderFocus, _xLeftBackMargin, 0, _imageSlider.getWidth() - _xRightBackMargin - _xLeftBackMargin, height, _imageSliderFocusCenter);
copy( _imageSliderFocus, _imageSlider.getWidth() - _xRightBackMargin, 0, _xRightBackMargin, height, _imageSliderFocusRight);
}
private void copy(Bitmap src, int x, int y, int width, int height, Bitmap dest) {
int[] argbData = new int[width * height];
src.getARGB(argbData, 0, width, x, y, width, height);
for(int tx = 0; tx < dest.getWidth(); tx += width) {
for(int ty = 0; ty < dest.getHeight(); ty += height) {
dest.setARGB(argbData, 0, width, tx, ty, width, height);
}
}
}
public void setState(int newState) {
if( newState > _numStates ){
throw new IllegalArgumentException();
} else {
_currentState = newState;
invalidate();
}
}
public int getState() {
return _currentState;
}
public int getNumStates() {
return _numStates;
}
public int getColour() {
if(_backgroundSelectedColours != null) {
return _backgroundSelectedColours[getState()];
}
return 0x000000;
}
public int getPreferredWidth() {
return _totalWidth;
}
public int getPreferredHeight() {
return _totalHeight;
}
protected void layout( int width, int height ) {
if (width < 0 || height < 0)
throw new IllegalArgumentException();
_totalWidth = width;
_totalHeight = Math.max(_imageSlider.getHeight(), _imageThumb.getHeight());
setExtent( _totalWidth, _totalHeight );
}
public void paint( Graphics g )
{
int sliderHeight = _imageSlider.getHeight();
int sliderBackYOffset = ( _totalHeight - sliderHeight ) >> 1;
int backgroundColor = _defaultBackgroundColour;
if( _backgroundSelectedColours != null || _backgroundColours != null ) {
if( _selected ) {
backgroundColor = _backgroundSelectedColours != null ? _backgroundSelectedColours[getState()] : _defaultSelectColour;
} else if(g.isDrawingStyleSet(Graphics.DRAWSTYLE_FOCUS)) {
backgroundColor = _backgroundColours != null ? _backgroundColours[getState()] : _defaultHoverColour;
} else {
backgroundColor = _defaultBackgroundColour;
}
}
g.setColor( backgroundColor );
g.fillRect( 1, sliderBackYOffset + 1, _totalWidth - 2, sliderHeight - 2 );
if(g.isDrawingStyleSet(Graphics.DRAWSTYLE_FOCUS)) {
paintSliderBackground( g, _imageSliderFocusLeft, _imageSliderFocusCenter, _imageSliderFocusRight );
} else {
paintSliderBackground( g, _imageSliderLeft, _imageSliderCenter, _imageSliderRight );
}
int thumbXOffset = ( ( _totalWidth - _thumbWidth ) * _currentState ) / _numStates;
g.drawBitmap( thumbXOffset, ( _totalHeight - _thumbHeight ) >> 1, _thumbWidth, _thumbHeight, _imageThumb, 0, 0 );
}
private void paintSliderBackground( Graphics g, Bitmap left, Bitmap middle, Bitmap right )
{
int sliderHeight = _imageSlider.getHeight();
int sliderBackYOffset = ( _totalHeight - sliderHeight ) >> 1;
g.drawBitmap( 0, sliderBackYOffset, _xLeftBackMargin, sliderHeight, left, 0, 0 );
g.tileRop( _rop, _xRightBackMargin, sliderBackYOffset, _totalWidth - _xLeftBackMargin - _xRightBackMargin, sliderHeight, middle, 0, 0 );
g.drawBitmap( _totalWidth - _xRightBackMargin, sliderBackYOffset, _xRightBackMargin, sliderHeight, right, 0, 0 );
}
public void paintBackground( Graphics g )
{
}
protected void drawFocus( Graphics g, boolean on )
{
boolean oldDrawStyleFocus = g.isDrawingStyleSet( Graphics.DRAWSTYLE_FOCUS );
try {
if( on ) {
g.setDrawingStyle( Graphics.DRAWSTYLE_FOCUS, true );
}
paint( g );
} finally {
g.setDrawingStyle( Graphics.DRAWSTYLE_FOCUS, oldDrawStyleFocus );
}
}
protected boolean touchEvent(TouchEvent message)
{
boolean isConsumed = false;
boolean isOutOfBounds = false;
int x = message.getX(1);
int y = message.getY(1);
if(x < 0 || y < 0 || x > getExtent().width || y > getExtent().height) {
isOutOfBounds = true;
}
switch(message.getEvent()) {
case TouchEvent.CLICK:
case TouchEvent.MOVE:
if(isOutOfBounds) return true;
_selected = true;
int stateWidth = getExtent().width / _numStates;
int numerator = x / stateWidth;
int denominator = x % stateWidth;
if( denominator > stateWidth / 2 ) {
numerator++;
}
_currentState = numerator;
invalidate();
isConsumed = true;
break;
case TouchEvent.UNCLICK:
if(isOutOfBounds) {
_selected = false;
return true;
}
_selected = false;
stateWidth = getExtent().width / _numStates;
numerator = x / stateWidth;
denominator = x % stateWidth;
if( denominator > stateWidth / 2 ) {
numerator++;
}
_currentState = numerator;
invalidate();
fieldChangeNotify(0);
isConsumed = true;
break;
}
return isConsumed;
}
protected boolean navigationMovement(int dx, int dy, int status, int time)
{
if( _selected )
{
if(dx > 0 || dy > 0) {
incrementState();
fieldChangeNotify( 0 );
return true;
} else if(dx < 0 || dy < 0) {
decrementState();
fieldChangeNotify( 0 );
return true;
}
}
return super.navigationMovement( dx, dy, status, time);
}
public void decrementState() {
if(_currentState > 0) {
_currentState--;
invalidate();
}
}
public void incrementState() {
if(_currentState < _numStates) {
_currentState++;
invalidate();
}
}
protected boolean invokeAction(int action) {
switch(action) {
case ACTION_INVOKE: {
toggleSelected();
return true;
}
}
return false;
}
protected boolean keyChar( char key, int status, int time ) {
if( key == Characters.SPACE || key == Characters.ENTER ) {
toggleSelected();
return true;
}
return false;
}
protected boolean trackwheelClick( int status, int time ) {
if( isEditable() ) {
toggleSelected();
return true;
}
return super.trackwheelClick(status, time);
}
private void toggleSelected() {
_selected = !_selected;
invalidate();
}
public void setDirty( boolean dirty )
{
}
public void setMuddy( boolean muddy )
{
}
}
答案 0 :(得分：1)
如果您使用下面的代码，您将获得实际需求，您可以通过在sliderfield引用上调用getValue（）方法将滑块当前值添加到您的屏幕类中。
实施 FieldChangeListener 界面并尝试覆盖 fieldChanged（）方法。
使用 HorizontalFieldManager 类和 setStatus（）方法， 如果你想在屏幕底部显示你的滑块，另外你可以正常显示它。
这里的代码：
public class SliderScreen extends MainScreen implements FieldChangeListener
{
private SliderField slider;
private HorizontalFieldManager hm;
public SliderField(){
slider = new SliderField(
Bitmap.getBitmapResource("slider2_thumb_normal.png"),
Bitmap.getBitmapResource("slider2_progress_normal.png"),
Bitmap.getBitmapResource("slider2_base_normal.png"),
Bitmap.getBitmapResource("slider2_thumb_focused.png"),
Bitmap.getBitmapResource("slider2_progress_focused.png"),
Bitmap.getBitmapResource("slider2_base_focused.png"), 8, 4,
8, 8, FOCUSABLE);
slider.setChangeListener(this);
hm = new HorizontalFieldManager();
hm.add(slider);
setStatus(hm);
}
public void fieldChanged(Field field, int context) {
try {
if (field == slider) {
int value = slider.getValue();
}
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (NullPointerException e) {
e.printStackTrace();
}
}
答案 1 :(得分：1)
我已经完成了如何使用此代码的简单示例，检查
public final class MyScreen extends MainScreen implements FieldChangeListener//,FocusChangeListener
{
/**
* Creates a new MyScreen object
*/
public MyScreen()
{
// Set the displayed title of the screen
setTitle("MyTitle");
SliderField slider;
slider = new SliderField(
Bitmap.getBitmapResource( "slider_thumb_normal.png" ), Bitmap.getBitmapResource( "slider_progress_normal.png" ), Bitmap.getBitmapResource( "slider_base_normal.png" ),
Bitmap.getBitmapResource( "slider_thumb_focused.png" ), Bitmap.getBitmapResource( "slider_progress_focused.png" ), Bitmap.getBitmapResource( "slider_base_focused.png"),
Bitmap.getBitmapResource( "slider_thumb_pressed.png" ), Bitmap.getBitmapResource( "slider_progress_pressed.png" ), Bitmap.getBitmapResource( "slider_base_pressed.png"),
10, 0, 12, 12, FOCUSABLE );
slider.setPadding( 20, 20, 20, 20 );
slider.setBackground( BackgroundFactory.createSolidBackground( 0xD3D3D3 ) );
slider.setChangeListener(this);
//slider.focusChangeNotify(0);
add( slider );
}
public void fieldChanged(Field field, int context) {
// TODO Auto-generated method stub
if(field instanceof SliderField)
{
SliderField temp = (SliderField)field;
System.out.println("Temp value is"+temp.getValue());
}
}
}