每当我从蓝牙接收新数据时，我需要在我的SurfaceView上通过画布绘制线条，第一次我可以成功绘制但是从第二次开始，surfacecreated（）方法永远不会被调用，请帮我如何重绘surfaceview.I添加我的布局和代码供进一步参考，
<LinearLayout
android:id="@+id/phasorPane"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="10dp"
android:orientation="vertical"
android:visibility="gone">
<com.rd.sands.bluetooth.MySurfaceView
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
从MianActivity我调用我的SurfaceView类，
myView = new MySurfaceView(getApplicationContext());
myView.invalidate();
我粘贴了整个SurfaceView类，请帮助我在哪里做错了，以及每当我收到新数据时如何重新绘制我的surfaceview
public class MySurfaceView extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder surfaceHolder;
Paint paint;
private int length;
Canvas canvas;
UserSessionManager sessionManager;
ArrayList resList = new ArrayList();
public MySurfaceView(Context context) {
super(context);
System.out.println("---------------MySurfaceView called");
init(length);
}
public MySurfaceView(Context context, AttributeSet attrs) {
super(context, attrs);
init(length);
}
public MySurfaceView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(length);
}
private void init(final int theta){
System.out.println("---------------init called");
paint = new Paint();
paint.setColor(Color.BLACK);
paint.setStrokeWidth(6);
paint.setStyle(Paint.Style.STROKE);
surfaceHolder = getHolder();
surfaceHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
System.out.println("---------------callback called");
}
protected void drawSomething(Canvas canvas) {
canvas.drawColor(Color.WHITE);
//surfaceHolder.setFormat(PixelFormat.TRANSPARENT);
//surfaceHolder.setFormat(PixelFormat.OPAQUE);
//canvas.drawColor( 0, PorterDuff.Mode.CLEAR );
sessionManager = new UserSessionManager(getContext());
ArrayList<String> retrievedValues = new ArrayList<>();
retrievedValues = sessionManager.retriveArrayList();
System.out.println("------Pref values(SurfaceView): " + retrievedValues + ", " + retrievedValues.size());
for (int i = 0; i < retrievedValues.size(); i++) {
System.out.println("--------------retrievedValues--> " + retrievedValues.get(i));
//findParameters(canvas.getWidth()/2,canvas.getHeight()/2,retrievedValues.get(i));
//System.out.println("findParameters("+x1+","+y1+","+arr+")");
int x1 = canvas.getWidth() / 2;
int y1 = canvas.getHeight() / 2;
System.out.println("findParameters(" + canvas.getWidth() / 2 + "," + canvas.getHeight() / 2 + "," + retrievedValues.get(i) + ")");
String replace = retrievedValues.get(i).replace("[", "");
System.out.println("replace1 " + replace);
String replace1 = replace.replace("]", "");
System.out.println("replace2 " + replace1);
if (replace1.contains(",")) {
String[] res = replace1.split(",");
String colorCode = res[0].trim();
String len = res[1].trim();
String angle = res[2].trim();
System.out.println("Splitted String,colorCode: " + colorCode + ",len: " + len + ",angle: " + angle);
//drawPhasorDiagram(x1,y1,len,Integer.parseInt(angle),colorCode);
if (len.equals("l/2")) {
length = canvas.getWidth() / 2;
System.out.println("length " + length);
} else if (len.equals("l/4")) {
length = canvas.getWidth() / 4;
System.out.println("length " + length);
}
System.out.println("drawPhasorDiagram" + "(x0,y0)->(" + x1 + "," + y1 + "),len: " + length + ",angle: " + angle + ",colorCode: " + colorCode + ")");
double x2 = x1 + (length * Math.cos(Math.toRadians(Integer.parseInt(angle) - 90)));
double y2 = y1 + (length * Math.sin(Math.toRadians(Integer.parseInt(angle) - 90)));
System.out.println("(x2,y2) " + "(" + x2 + "," + y2 + ")");
switch(colorCode){
case "VR":
paint.setColor(Color.RED);
paint.setStrokeWidth(6);
break;
case "VY":
paint.setColor(Color.YELLOW);
paint.setStrokeWidth(6);
break;
case "VB":
paint.setColor(Color.BLUE);
paint.setStrokeWidth(6);
break;
case "IR":
paint.setColor(Color.RED);
paint.setStrokeWidth(3);
break;
case "IY":
paint.setColor(Color.YELLOW);
paint.setStrokeWidth(3);
break;
case "IB":
paint.setColor(Color.BLUE);
paint.setStrokeWidth(3);
break;
}
paint.setStyle(Paint.Style.STROKE);
System.out.println("drawLine(" + canvas.getWidth() / 2 + "," + canvas.getHeight() / 2 + "," + (float) x2 + "," + (float) y2 + ",p)");
canvas.drawLine(canvas.getWidth() / 2, canvas.getHeight() / 2, (float) x2, (float) y2, paint);
//canvas.drawLine(340,407, (float) 340.0, (float) 67.0,paint);
System.out.println("drewLine");
sessionManager.clearSession();
invalidate();
}
}
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
System.out.println("onDraw()");
}
@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
System.out.println("---------------surfaceCreated called");
setWillNotDraw(false); //Allows us to use invalidate() to call onDraw()
canvas = surfaceHolder.lockCanvas(null);
//canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);
drawSomething(canvas);
surfaceHolder.unlockCanvasAndPost(canvas);
}
@Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {
System.out.println("---------------surfaceChanged called");
postInvalidate();
}
@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
System.out.println("---------------surfaceDestroyed called");
}
}
我粘贴了我的logcat以供进一步参考，从logcat我们可以来konw surfacecreated（）第二次收到新数据时不会被调用
07-17 10:22:20.285 17169-17169/com.rd.sands.bluetooth I/System.out: --------------Received Data(writeMessage)-- $L,VB,l/2,270
07-17 10:22:20.285 17169-17169/com.rd.sands.bluetooth I/System.out: --------------ArrayList-- [$L, VB, l/2, 270]
07-17 10:22:20.285 17169-17169/com.rd.sands.bluetooth I/System.out: --------------Received Data is for Phasor Diagram--
07-17 10:22:20.290 17169-17169/com.rd.sands.bluetooth I/System.out: --------------Line ArrayList after removing spl chars-- [VB, l/2, 270]
07-17 10:22:20.290 17169-17169/com.rd.sands.bluetooth I/System.out: --------------LinkedList--> [VB, l/2, 270], 1
07-17 10:22:20.290 17169-17169/com.rd.sands.bluetooth D/Stored sharedPref: [[VB, l/2, 270]]
07-17 10:22:20.295 17169-17169/com.rd.sands.bluetooth I/System.out: ---------------MySurfaceView called
07-17 10:22:20.295 17169-17169/com.rd.sands.bluetooth I/System.out: ---------------init called
07-17 10:22:20.295 17169-17169/com.rd.sands.bluetooth I/System.out: ---------------callback called
07-17 10:22:20.295 17169-17169/com.rd.sands.bluetooth I/System.out: ---------------myview.invalidate()
07-17 10:22:20.320 17169-17169/com.rd.sands.bluetooth I/System.out: ---------------surfaceCreated called
07-17 10:22:20.325 17169-17169/com.rd.sands.bluetooth D/Retrieve sharedPref: [[VB, l/2, 270]]
07-17 10:22:20.330 17169-17169/com.rd.sands.bluetooth I/System.out: ------Pref values(SurfaceView): [[VB, l/2, 270]], 1
07-17 10:22:20.330 17169-17169/com.rd.sands.bluetooth I/System.out: --------------retrievedValues--> [VB, l/2, 270]
07-17 10:22:20.330 17169-17169/com.rd.sands.bluetooth I/System.out: findParameters(340,407,[VB, l/2, 270])
07-17 10:22:20.330 17169-17169/com.rd.sands.bluetooth I/System.out: replace1 VB, l/2, 270]
07-17 10:22:20.330 17169-17169/com.rd.sands.bluetooth I/System.out: replace2 VB, l/2, 270
07-17 10:22:20.330 17169-17169/com.rd.sands.bluetooth I/System.out: Splitted String,colorCode: VB,len: l/2,angle: 270
07-17 10:22:20.330 17169-17169/com.rd.sands.bluetooth I/System.out: length 340
07-17 10:22:20.330 17169-17169/com.rd.sands.bluetooth I/System.out: drawPhasorDiagram(x0,y0)->(340,407),len: 340,angle: 270,colorCode: VB)
07-17 10:22:20.335 17169-17169/com.rd.sands.bluetooth I/System.out: (x2,y2) (0.0,407.00000000000006)
07-17 10:22:20.335 17169-17169/com.rd.sands.bluetooth I/System.out: drawLine(340,407,0.0,407.0,p)
07-17 10:22:20.335 17169-17169/com.rd.sands.bluetooth I/System.out: drewLine
07-17 10:22:20.335 17169-17169/com.rd.sands.bluetooth I/System.out: UserSessionManager->clearSession()
07-17 10:22:20.340 17169-17169/com.rd.sands.bluetooth I/System.out: ---------------surfaceChanged called
07-17 10:22:20.345 17169-17169/com.rd.sands.bluetooth I/System.out: onDraw()
07-17 10:22:20.365 17169-17169/com.rd.sands.bluetooth I/System.out: onDraw()
07-17 10:22:26.820 17169-17637/com.rd.sands.bluetooth I/System.out: -------------Series Removed
07-17 10:22:26.820 17169-17637/com.rd.sands.bluetooth I/System.out: -------------Bar Series Removed
07-17 10:22:26.820 17169-17637/com.rd.sands.bluetooth I/System.out: -------------New Series
07-17 10:22:26.820 17169-17169/com.rd.sands.bluetooth I/System.out: --------------Received Data(writeMessage)-- $L,VB,l/2,270
07-17 10:22:26.820 17169-17169/com.rd.sands.bluetooth I/System.out: --------------ArrayList-- [$L, VB, l/2, 270]
07-17 10:22:26.820 17169-17169/com.rd.sands.bluetooth I/System.out: --------------Received Data is for Phasor Diagram--
07-17 10:22:26.820 17169-17169/com.rd.sands.bluetooth I/System.out: --------------Line ArrayList after removing spl chars-- [VB, l/2, 270]
07-17 10:22:26.820 17169-17169/com.rd.sands.bluetooth I/System.out: --------------LinkedList--> [VB, l/2, 270], 1
07-17 10:22:26.820 17169-17169/com.rd.sands.bluetooth D/Stored sharedPref: [[VB, l/2, 270]]
07-17 10:22:26.820 17169-17169/com.rd.sands.bluetooth I/System.out: ---------------MySurfaceView called
07-17 10:22:26.820 17169-17169/com.rd.sands.bluetooth I/System.out: ---------------init called
07-17 10:22:26.820 17169-17169/com.rd.sands.bluetooth I/System.out: ---------------callback called
07-17 10:22:26.820 17169-17169/com.rd.sands.bluetooth I/System.out: ---------------myview.invalidate()
07-17 10:27:18.840 17169-17169/com.rd.sands.bluetooth V/ActivityThread: updateVisibility : ActivityRecord{6d487cf token=android.os.BinderProxy@a0d65ef {com.rd.sands.bluetooth/com.rd.sands.bluetooth.MainActivity}} show : true
我添加了我的sessionmanager类以供参考，
public class UserSessionManager {
SharedPreferences pref;
SharedPreferences.Editor editor;
Context _context;
int PRIVATE_MODE = 0;
private static final String PREFER_NAME = "MyPref";
ArrayList<String> arrPackage = new ArrayList<>();
public UserSessionManager(Context context){
this._context = context;
pref = _context.getSharedPreferences(PREFER_NAME, PRIVATE_MODE);
editor = pref.edit();
}
public void saveArrayList(ArrayList<String> arrayList) {
Set<String> set = new HashSet<String>();
set.addAll(arrayList);
editor.putStringSet("DATE_LIST", set);
editor.apply();
Log.d("Stored sharedPref",""+set);
}
public ArrayList<String> retriveArrayList() {
Set<String> set = pref.getStringSet("DATE_LIST", null);
arrPackage.addAll(set);
Log.d("Retrieve sharedPref",""+set);
return arrPackage;
}
public void clearSession(){
System.out.println("UserSessionManager->clearSession() ");
editor.clear();
editor.commit();
}
}