我有IndicationBar类，它应该绘制带有徽标的矩形和int值更改矩形颜色。我是java和android的新手，所以我每天都在学习。
此时int的值在其他类中发生变化，我称之为BluetoothChat.statusSviesos。它的public static int。我是否需要创建接口监听器或者每次更改int时如何运行private void Sviesos()？它在开始时只运行一次。
public class IndicationBar extends View {
private static final String TAG = IndicationBar.class.getSimpleName();
// drawing tools
private RectF Rect;
private Paint rectPaint;
private Paint rimCirclePaint;
private RectF faceRect;
private Bitmap faceTexture;
private Paint facePaint;
private Paint rimShadowPaint;
private Paint titlePaint;
private Path titlePath;
private Paint logoPaint;
private Bitmap logo;
private Matrix logoMatrix;
private float logoScale;
private Paint backgroundPaint;
// end drawing tools
private Bitmap background; // holds the cached static part
public IndicationBar(Context context) {
super(context);
init();
}
public IndicationBar(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public IndicationBar(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
Bundle bundle = (Bundle) state;
Parcelable superState = bundle.getParcelable("superState");
super.onRestoreInstanceState(superState);
}
private void init() {
initDrawingTools();
}
// private String getTitle() {
// return "DANCER";
// }
private void Sviesos(){
//Rect = new RectF(0.1f, 0.1f, 0.9f, 0.9f);
//rectPaint = new Paint();
//valueSviesos = BluetoothChat.statusSviesos;
switch(BluetoothChat.statusSviesos){
case 0 : rectPaint.setColor(Color.parseColor("#1BA1E2"));
break;
case 1 : rectPaint.setColor(Color.parseColor("#A05000"));
break;
case 2 : rectPaint.setColor(Color.parseColor("#E671B8"));
break;
case 3 : rectPaint.setColor(Color.parseColor("#F09609"));
break;
case 4 : rectPaint.setColor(Color.parseColor("#1BA1E2"));
break;
}
//rectPaint.setFlags(Paint.ANTI_ALIAS_FLAG);
}
private void initDrawingTools() {
Rect = new RectF(0.1f, 0.1f, 0.9f, 0.9f);
rectPaint = new Paint();
rectPaint.setColor(Color.parseColor("#8CBF26"));
rectPaint.setFlags(Paint.ANTI_ALIAS_FLAG);
Sviesos();
rimCirclePaint = new Paint();
rimCirclePaint.setAntiAlias(true);
rimCirclePaint.setStyle(Paint.Style.STROKE);
rimCirclePaint.setColor(Color.argb(0x4f, 0x33, 0x36, 0x33));
rimCirclePaint.setStrokeWidth(0.005f);
float rimSize = 0.02f;
faceRect = new RectF();
faceRect.set(Rect.left + rimSize, Rect.top + rimSize,
Rect.right - rimSize, Rect.bottom - rimSize);
faceTexture = BitmapFactory.decodeResource(getContext().getResources(),
R.drawable.plastic);
BitmapShader paperShader = new BitmapShader(faceTexture,
Shader.TileMode.MIRROR,
Shader.TileMode.MIRROR);
Matrix paperMatrix = new Matrix();
facePaint = new Paint();
facePaint.setFilterBitmap(true);
paperMatrix.setScale(1.0f / faceTexture.getWidth(),
1.0f / faceTexture.getHeight());
paperShader.setLocalMatrix(paperMatrix);
facePaint.setStyle(Paint.Style.FILL);
facePaint.setShader(paperShader);
rimShadowPaint = new Paint();
rimShadowPaint.setShader(new RadialGradient(0.5f, 0.5f, faceRect.width() / 2.0f,
new int[] { 0x00000000, 0x00000500, 0x50000500 },
new float[] { 0.96f, 0.96f, 0.99f },
Shader.TileMode.MIRROR));
rimShadowPaint.setStyle(Paint.Style.FILL);
titlePaint = new Paint();
titlePaint.setColor(Color.parseColor("#1BA1E2"));
titlePaint.setAntiAlias(true);
titlePaint.setTypeface(Typeface.DEFAULT_BOLD);
titlePaint.setTextAlign(Paint.Align.CENTER);
titlePaint.setTextSize(0.09f);
titlePaint.setTextScaleX(0.9f);
titlePath = new Path();
titlePath.addArc(new RectF(0.24f, 0.24f, 0.76f, 0.76f), -180.0f, -180.0f);
logoPaint = new Paint();
logoPaint.setFilterBitmap(true);
logo = BitmapFactory.decodeResource(getContext().getResources(), R.drawable.sviesos);
logoMatrix = new Matrix();
logoScale = (1.0f / logo.getWidth()) * 0.3f;;
logoMatrix.setScale(logoScale, logoScale);
backgroundPaint = new Paint();
backgroundPaint.setFilterBitmap(true);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Log.d(TAG, "Width spec: " + MeasureSpec.toString(widthMeasureSpec));
Log.d(TAG, "Height spec: " + MeasureSpec.toString(heightMeasureSpec));
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int chosenWidth = chooseDimension(widthMode, widthSize);
int chosenHeight = chooseDimension(heightMode, heightSize);
int chosenDimension = Math.min(chosenWidth, chosenHeight);
setMeasuredDimension(chosenDimension, chosenDimension);
}
private int chooseDimension(int mode, int size) {
if (mode == MeasureSpec.AT_MOST || mode == MeasureSpec.EXACTLY) {
return size;
} else { // (mode == MeasureSpec.UNSPECIFIED)
return getPreferredSize();
}
}
// in case there is no size specified
private int getPreferredSize() {
return 300;
}
private void drawRect(Canvas canvas) {
// first, draw the metallic body
canvas.drawRect(Rect, rectPaint);
// now the outer rim circle
//canvas.drawOval(rimRect, rimCirclePaint);
}
// private void drawFace(Canvas canvas) {
// canvas.drawOval(faceRect, facePaint);
// // draw the inner rim circle
// canvas.drawOval(faceRect, rimCirclePaint);
// // draw the rim shadow inside the face
// canvas.drawOval(faceRect, rimShadowPaint);
// }
private void drawBackground(Canvas canvas) {
if (background == null) {
Log.w(TAG, "Background not created");
} else {
canvas.drawBitmap(background, 0, 0, backgroundPaint);
}
}
@Override
protected void onDraw(Canvas canvas) {
drawBackground(canvas);
float scale = (float) getWidth();
canvas.save(Canvas.MATRIX_SAVE_FLAG);
canvas.scale(scale, scale);
drawLogo(canvas);
canvas.restore();
}
private void drawLogo(Canvas canvas) {
canvas.save(Canvas.MATRIX_SAVE_FLAG);
canvas.translate(0.5f - logo.getWidth() * logoScale / 2.0f,
0.5f - logo.getHeight() * logoScale / 2.0f);
canvas.drawBitmap(logo, logoMatrix, logoPaint);
canvas.restore();
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
Log.d(TAG, "Size changed to " + w + "x" + h);
regenerateBackground();
}
private void regenerateBackground() {
// free the old bitmap
Sviesos();
if (background != null) {
background.recycle();
}
background = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);
Canvas backgroundCanvas = new Canvas(background);
float scale = (float) getWidth();
backgroundCanvas.scale(scale, scale);
drawRect(backgroundCanvas);
}
}
答案 0 :(得分：1)
使用观察者模式。更改BluetoothChat
public class BluetoothChat {
private static int statusSviesos;
//the list of observers
private static List<Observer> observerList;
//adds an observer to observe statusSciesos
public static void addStatusSviesosObserver(Observer observer) {
observerList.add(observer);
}
//getter function returns the value
public static int getStatusSviesos(){
return statusSviesos;
}
//setter function sets the value and notifies observer
public static void setStatusSviesos(int statusSviesos){
BluetoothChat.statusSviesos=statusSviesos;
for(Observer current: observerList){
current.notifyChange(statusSviesos);
}
}
public static interface Observer {
public void notifyChange(int newStatus);
}
...
然后在IndicationBar中创建一个Observer并将其添加到BluetoothChat：
Observer observer = new Observer() {
@Override
public void notifyChange(int newStatus) {
Sviesos();
}
};
BluetoothChat.addStatusSviesosObserver(observer);
这是Observer模式的原始实现。应该有一个removeObserver方法，它不是线程安全的。 Java中有一个默认的实现（Observer-class和Observable-class），还有像PropertyChangeObserver这样的替代实现。但对于您当前的用例，这应该可以胜任。另请阅读Wikipedia和Vogellas tutorial
一般提示：