我创建了一个简单的绘图应用程序，其中我使用搜索栏来获得笔触宽度。但是只要我改变笔划宽度，完整图纸的宽度就会改变。当我改变笔的颜色时也是如此。如何为每条路径单独指定笔画属性？
我尝试了很多答案，但无法得到正确的结果。
我已经尝试存储路径以及与之关联的相应paint然后绘制它。但这也行不通。
public class MainActivity extends AppCompatActivity {
View mView;
private Paint mPaint;
SeekBar mSeekbar;
int penColor = Color.BLACK;
int bgColor = Color.WHITE;
int StrokeWidth = 12;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
LinearLayout layout = (LinearLayout) findViewById(R.id.myDrawing);
mView = new DrawingView(this);
mSeekbar = (SeekBar) findViewById(R.id.seek);
mSeekbar.getProgressDrawable().setColorFilter(Color.RED, PorterDuff.Mode.SRC_IN);
mSeekbar.getThumb().setColorFilter(Color.RED, PorterDuff.Mode.SRC_IN);
layout.addView(mView, new ActionBar.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT));
((DrawingView) mView).init();
penSize();
}
public void penSize() {
mSeekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
((DrawingView) mView).changePenSize(StrokeWidth);
StrokeWidth = i;
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
((DrawingView) mView).changePenSize(StrokeWidth);
}
});
}
class DrawingView extends View {
private Path path;
private Bitmap mBitmap;
private Canvas mCanvas;
public DrawingView(Context context) {
super(context);
path = new Path();
mBitmap = Bitmap.createBitmap(820, 480, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
this.setBackgroundColor(bgColor);
mPaint = new Paint();
mPaint.setDither(true);
mPaint.setColor(penColor);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(StrokeWidth);
}
public void changePenSize(int size) {
StrokeWidth = size;
mPaint.setStrokeWidth(StrokeWidth);
invalidate();
}
public void init() {
mPaint = new Paint();
mPaint.setDither(true);
mPaint.setColor(penColor);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(StrokeWidth);
}
public void setBGColor(int color) {
bgColor = color;
this.setBackgroundColor(bgColor);
invalidate();
}
public void ClearPath() {
path.reset();
bgColor = Color.WHITE;
penColor = Color.BLACK;
init();
invalidate();
}
public void changePenColor() {
mPaint.setColor(penColor);
invalidate();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float touchX = event.getX();
float touchY = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
path.moveTo(touchX, touchY);
break;
case MotionEvent.ACTION_MOVE:
path.lineTo(touchX, touchY);
break;
case MotionEvent.ACTION_UP:
mCanvas.drawPath(path, mPaint);
break;
default:
return false;
}
invalidate();
return true;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawPath(path, mPaint);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
File myDir = new File(Environment.getExternalStorageDirectory(),
"Drawings");
myDir.mkdirs();
Date now = new Date();
String fname = "image" + now.getDate() + now.getSeconds() + ".jpg";
File file = new File(myDir, fname);
//noinspection SimplifiableIfStatement
if (id == R.id.clear) {
AlertDialog.Builder alert = new AlertDialog.Builder(MainActivity.this);
alert.setTitle("Do you really want to clear ?\nYou can save before clearing.");
alert.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
((DrawingView) mView).ClearPath();
Toast.makeText(MainActivity.this, "Done", Toast.LENGTH_SHORT).show();
}
});
alert.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
}
});
alert.show();
return true;
} else if (id == R.id.bgColor) {
bgColor();
} else if (id == R.id.penColor) {
penColor();
} else if (id == R.id.screenshot) {
takeScreenshot();
return true;
}
return super.onOptionsItemSelected(item);
}
private void penColor() {
AmbilWarnaDialog dialog = new AmbilWarnaDialog(MainActivity.this, Color.BLACK, new AmbilWarnaDialog.OnAmbilWarnaListener() {
@Override
public void onOk(AmbilWarnaDialog dialog, int color) {
penColor = color;
((DrawingView) mView).changePenColor();
}
@Override
public void onCancel(AmbilWarnaDialog dialog) {
}
});
dialog.show();
}
private void bgColor() {
AmbilWarnaDialog dialog = new AmbilWarnaDialog(MainActivity.this, Color.BLACK, new AmbilWarnaDialog.OnAmbilWarnaListener() {
@Override
public void onOk(AmbilWarnaDialog dialog, int color) {
bgColor = color;
((DrawingView) mView).setBGColor(bgColor);
}
@Override
public void onCancel(AmbilWarnaDialog dialog) {
}
});
dialog.show();
}
private void takeScreenshot() {
mView.setDrawingCacheEnabled(true);
String filename= UUID.randomUUID().toString() + ".png";
String imgSaved = MediaStore.Images.Media.insertImage(
getContentResolver(), mView.getDrawingCache(),
filename, "drawing");
if (imgSaved != null) {
Toast.makeText(getApplicationContext(),
"Drawing saved to Gallery! ", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(),
"Oops! Image could not be saved.", Toast.LENGTH_SHORT).show();
}
mView.destroyDrawingCache();
}
}
答案 0 :(得分：0)
class DrawingView extends View {
ArrayList<DrawingPath> paths;
private DrawingPath drawingPath;
private Bitmap mBitmap;
private Canvas mCanvas;
public DrawingView(Context context) {
super(context);
paths = new ArrayList<>();
mBitmap = Bitmap.createBitmap(820, 480, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
this.setBackgroundColor(bgColor);
mPaint = new Paint();
mPaint.setDither(true);
mPaint.setColor(penColor);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(StrokeWidth);
}
public void changePenSize(int size) {
StrokeWidth = size;
mPaint.setStrokeWidth(StrokeWidth);
}
public void init() {
mPaint = new Paint();
mPaint.setDither(true);
mPaint.setColor(penColor);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(StrokeWidth);
}
public void setBGColor(int color) {
bgColor = color;
this.setBackgroundColor(bgColor);
invalidate();
}
public void ClearPath() {
paths.clear();
bgColor = Color.WHITE;
penColor = Color.BLACK;
init();
invalidate();
}
public void changePenColor() {
mPaint.setColor(penColor);
invalidate();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float touchX = event.getX();
float touchY = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
drawingPath = new DrawingPath(mPaint.getStrokeWidth());
paths.add(drawingPath);
drawingPath.path.moveTo(touchX, touchY);
break;
case MotionEvent.ACTION_MOVE:
drawingPath.path.lineTo(touchX, touchY);
break;
case MotionEvent.ACTION_UP:
mCanvas.drawPath(drawingPath.path, mPaint);
break;
default:
return false;
}
invalidate();
return true;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
for (DrawingPath drawingPath : paths) {
mPaint.setStrokeWidth(drawingPath.strokeWidth);
canvas.drawPath(drawingPath.path, mPaint);
}
}
}
class DrawingPath {
Path path;
float strokeWidth;
DrawingPath(float strokeWidth) {
path = new Path();
this.strokeWidth = strokeWidth;
}
}
我希望这会有所帮助。您可以将其他属性（如颜色，样式等）添加到DrawingPath模型中。