我使用下面给出的代码基于用户手指移动绘制了多边形路径。
paint = new Paint();
strokePaint = new Paint();
//paint.setColor(Color.RED);
paint.setARGB(125, 255, 0, 0);
paint.setStyle(Style.FILL);
paint.setPathEffect(new DashPathEffect(new float[] {10,20}, 0));
paint.setStrokeWidth(5);
paint.setAntiAlias(true);
wallpath = new Path();
在onDraw上我使用此代码绘制图形
wallpath.lineTo(endPoint.x, endPoint.y);
canvas.drawPath(wallpath, paint);
上面的代码工作正常。但是在双击时我想改变填充颜色。为此，我使用此代码
paint.setARGB(125, 225, 0, 0);
paint.setStyle(Style.FILL);
paint.setPathEffect(new DashPathEffect(new float[] {10,20}, 0));
paint.setStrokeWidth(5);
paint.setAntiAlias(true);
invalidate();
但它似乎没有起作用。我该怎么做呢？
完整的参考代码
public class HotspotView extends View
{
private Paint paint,strokePaint;
private PointF startPoint, endPoint;
private boolean isDrawing,isFinished,isAnimating,isRecording,isRedrawing;
private Path wallpath;
private ArrayList<PointF> points;
private RectF rectF;
private CurlView curlView;
public int imageWidth;
private String fileName;
private AudioRecorder audioRecorder;
private GestureDetector gestureDetector;
public static int LONG_PRESS_TIME = 500; // Time in miliseconds
private AudioPlayer player;
final Handler _handler = new Handler();
Runnable _longPressed = new Runnable() {
public void run() {
Log.i("info","LongPress");
isRecording = true;
isDrawing = false;
isRedrawing = true;
///////////////////******************///////////////////////
//paint = new Paint();
//strokePaint = new Paint();
//paint.setColor(Color.RED);
paint.setARGB(125, 225, 0, 0);
paint.setStyle(Style.FILL);
paint.setPathEffect(new DashPathEffect(new float[] {10,20}, 0));
paint.setStrokeWidth(5);
paint.setAntiAlias(true);
invalidate();
//////////////////*****************////////////////////////
audioRecorder = new AudioRecorder(fileName);
setFileName();
audioRecorder.startRecording(fileName);
}
};
public HotspotView(Context context)
{
super(context);
init();
gestureDetector = new GestureDetector(context, new GestureListener());
}
public HotspotView(Context context, AttributeSet attrs)
{
super(context, attrs);
init();
gestureDetector = new GestureDetector(context, new GestureListener());
}
public HotspotView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
gestureDetector = new GestureDetector(context, new GestureListener());
}
private void init()
{
isRecording = false;
isRedrawing = false;
paint = new Paint();
strokePaint = new Paint();
//paint.setColor(Color.RED);
paint.setARGB(125, 255, 0, 0);
paint.setStyle(Style.FILL);
paint.setPathEffect(new DashPathEffect(new float[] {10,20}, 0));
paint.setStrokeWidth(5);
paint.setAntiAlias(true);
wallpath = new Path();
points = new ArrayList<PointF>();
rectF = new RectF();
rectF.set(-1.7883435f, 1.0f, 1.7883435f, -1.0f);
}
@Override
protected void onDraw(Canvas canvas)
{
if(isAnimating)
{
PointF point = this.translate(points.get(0));
if(wallpath == null)
{
wallpath = new Path();
}
wallpath.moveTo(point.x, point.y);
isDrawing = false;
isFinished = false;
for(int i=1;i<points.size();i++)
{
if(isRedrawing)
{
point = points.get(i);
}
else
{
point = this.translate(points.get(i));
}
wallpath.lineTo(point.x, point.y);
//Log.d("Points", "X = "+point.x);
//Log.d("Points", "Y = "+point.y);
canvas.drawPath(wallpath, paint);
}
if(isRedrawing)
{
point = points.get(0);
}
else
{
point = this.translate(points.get(0));
}
wallpath.lineTo(point.x, point.y);
canvas.drawPath(wallpath, paint);
isFinished = true;
}
else if(isDrawing)
{
//canvas.drawLine(startPoint.x, startPoint.y, endPoint.x, endPoint.y, paint);
wallpath.lineTo(endPoint.x, endPoint.y);
canvas.drawPath(wallpath, paint);
}
if(isFinished)
{
//wallpath.lineTo(endPoint.x, endPoint.y);
//canvas.drawPath(wallpath, strokePaint);
wallpath.close();
}
}
@Override
public boolean onTouchEvent(MotionEvent event)
{
boolean result = gestureDetector.onTouchEvent(event);//return the double tap events
if(!isAnimating)
{
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN:
isDrawing = true;
//wallpath.reset();
_handler.postDelayed(_longPressed, LONG_PRESS_TIME);
startPoint = new PointF(event.getX(), event.getY());
endPoint = new PointF();
endPoint.x = event.getX();
endPoint.y = event.getY();
wallpath.moveTo(endPoint.x,endPoint.y);
points.add(startPoint);
//invalidate();
break;
case MotionEvent.ACTION_MOVE:
PointF point = new PointF(event.getX(),event.getY());
endPoint.x = event.getX();
endPoint.y = event.getY();
double distance = Math.sqrt(Math.pow((endPoint.x - startPoint.x), 2)+ Math.pow(endPoint.y - startPoint.y,2));
if(distance >2)
{
_handler.removeCallbacks(_longPressed);
if(!isRecording)
{
if(isDrawing)
{
Log.d("Point", "X = "+(event.getX() - this.getLeft()));
Log.d("Point", "Y = "+(event.getY() - this.getTop()));
points.add(point);
invalidate();
}
}
}
break;
case MotionEvent.ACTION_UP:
_handler.removeCallbacks(_longPressed);
if(isRecording)
{
audioRecorder.stopRecording();
isRecording = false;
}
if(isDrawing)
{
endPoint.x = startPoint.x;//event.getX();
endPoint.y = startPoint.y;//event.getY();
strokePaint.setARGB(255, 255, 0, 0);
strokePaint.setStyle(Style.STROKE);
strokePaint.setPathEffect(new DashPathEffect(new float[] {5,10}, 0));
strokePaint.setStrokeWidth(5);
strokePaint.setAntiAlias(true);
isFinished = true;
invalidate();
//isDrawing = false;
}
break;
default:
break;
}
}
return result;
}
答案 0 :(得分：1)
要填写Path，您需要先关闭它。调用Path.close()关闭当前轮廓。
如果您想更改线条的颜色，则需要使用paint.setStyle(Paint.Style.STROKE)并使用paint.setColor()。
...当然，您需要使视图无效，onDraw() - 您绘制路径的地方 - 再次被调用。
答案 1 :(得分：1)
如果您可以从onDraw方法发布更多代码会很有帮助，因为很难说出什么时候调用它。
我的猜测是无效工作正常，但每次调用onDraw时，你重置你的绘画设置（paint = new Paint（）），所以根本不使用不同颜色的绘画。
编辑：
我不能告诉你你有哪个确切的行，但是在我看来它与路径或绘画设置无关。您的代码中有太多状态标志（isDrawing，isFinished，isAnimating，isRecording，isRedrawing），您无法再控制它。
OnDraw方法应该简单地绘制点：
@Override
protected void onDraw(Canvas canvas) {
if (points.size() > 0) {
PointF point = points.get(0);
wallpath.rewind();
wallpath.moveTo(point.x, point.y);
for (int i = 1; i < points.size(); i++) {
point = points.get(i);
wallpath.lineTo(point.x, point.y);
}
canvas.drawPath(wallpath, paint);
}
}
简化您的代码。只是为了测试：用我的命题替换你的onDraw方法，你会看到路径会在长按时改变颜色。