有人知道如何清除位图和画布吗？我认为 somewere 是错误的或不完整的代码。例如，在 public void forceRedraw() 的 FirstActivity.java 上，我收到一条消息以在 invalidate() 上创建方法。如果您需要其他课程，请告诉我。我真的不知道我的错误在哪里。我正在使用以下代码。它有点大，但希望能理解它。
这是我的 FirstActivity.java
public class FirstActivity extends Activity implements ColorPickerDialog.OnColorChangedListener {
Paint mPaint;
private Paint paint = new Paint();
private Path path = new Path();
CanvasView myView;
static LinearLayout ll;
ImageView imageViewLine;
ImageView imageViewRectangle;
private ImageView imageViewErase;
private ImageView imageViewFreehand;
private ImageView imageViewUndo;
private ImageView imageViewRedo;
private final int CONTEXT_MENU_LINES_ID = 1;
private final int CONTEXT_MENU_SHAPES_ID = 2;
private final int CONTEXT_MENU_COLOR_ID = 3;
private IconContextMenu iconContextMenuLine = null;
private IconContextMenu iconContextMenuShapes = null;
private IconContextMenu iconContextMenuColors = null;
private final int MENU_ITEM_1_ACTION = 1;
private final int MENU_ITEM_2_ACTION = 2;
private final int MENU_ITEM_3_ACTION = 3;
private final int MENU_ITEM_4_ACTION = 4;
private final int MENU_ITEM_5_ACTION = 5;
private final int MENU_ITEM_6_ACTION = 6;
private final int MENU_ITEM_7_ACTION = 7;
private final int MENU_ITEM_8_ACTION = 8;
private ImageView imageViewText;
private ImageView imageViewColor;
private File folderAppointment;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.first_activity);
initContextMenus();
myView = (CanvasView)this.findViewById(R.id.canvasView);
ll = (LinearLayout) this.findViewById(R.id.linearLayout2);
ll.setVisibility(LinearLayout.GONE);
imageViewLine = (ImageView)this.findViewById(R.id.imageViewLine);
imageViewLine.setOnClickListener(new OnClickListener() {
@SuppressWarnings("deprecation")
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Line tool clicked", Toast.LENGTH_SHORT).show();
myView.setMode(1); //draw line
myView.setOnTouchListener(myView.drawLineListener);
showDialog(CONTEXT_MENU_LINES_ID,null);
}
});
imageViewRectangle = (ImageView)this.findViewById(R.id.imageViewSquare);
imageViewRectangle.setOnTouchListener(new OnTouchListener() {
@SuppressWarnings("deprecation")
public boolean onTouch(View v, MotionEvent event) {
if(event.getAction() == MotionEvent.ACTION_DOWN)
{
Toast.makeText(getApplicationContext(), "Rectangle tool clicked", Toast.LENGTH_SHORT).show();
myView.setMode(5); //draw rectangle
showDialog(CONTEXT_MENU_SHAPES_ID,null);
return true;
}
return false;
}
});
imageViewErase = (ImageView)this.findViewById(R.id.imageViewEraser);
imageViewErase.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Eraser tool clicked", Toast.LENGTH_SHORT).show();
myView.setMode(6); //eraser
}
});
imageViewFreehand = (ImageView)this.findViewById(R.id.imageViewSquiggle);
imageViewFreehand.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Squiggle tool clicked", Toast.LENGTH_SHORT).show();
myView.setMode(7);//free hand draw
}
});
imageViewUndo = (ImageView)this.findViewById(R.id.imageViewUndo);
imageViewUndo.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Undo tool clicked", Toast.LENGTH_SHORT).show();
myView.setMode(9);//undo
}
});
imageViewRedo = (ImageView)this.findViewById(R.id.imageViewRedo);
imageViewRedo.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Redo tool clicked", Toast.LENGTH_SHORT).show();
myView.setMode(10);//redo
}
});
imageViewText = (ImageView)this.findViewById(R.id.imageViewText);
imageViewText.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Text tool clicked", Toast.LENGTH_SHORT).show();
myView.setMode(8);//text input
}
});
imageViewColor = (ImageView)this.findViewById(R.id.imageViewColor);
imageViewColor.setOnClickListener(new OnClickListener() {
@SuppressWarnings("deprecation")
public void onClick(View v) {
Toast.makeText(getApplicationContext(), "Select color", Toast.LENGTH_SHORT).show();
//myView.setMode(5); //draw rectangle
showDialog(CONTEXT_MENU_COLOR_ID,null);
}
});
}
@SuppressWarnings("deprecation") // to be optimized using switch instead of nested if-s
protected Dialog onCreateDialog(int id) {
if (id == CONTEXT_MENU_LINES_ID) {
return iconContextMenuLine.createMenu("Lines");
}
else if(id == CONTEXT_MENU_SHAPES_ID){
return iconContextMenuShapes.createMenu("Shapes");
}
else if(id == CONTEXT_MENU_COLOR_ID){
return iconContextMenuColors.createMenu("Choose color");
}
return super.onCreateDialog(id);
}
public void initContextMenus(){
Resources res = getResources();
//init icon context menu
iconContextMenuLine = new IconContextMenu(this, CONTEXT_MENU_LINES_ID);
iconContextMenuLine.addItem(res, "", R.drawable.line, MENU_ITEM_2_ACTION);
iconContextMenuLine.addItem(res, "", R.drawable.linie_taiata, MENU_ITEM_4_ACTION);
iconContextMenuLine.setOnClickListener(new IconContextMenu.IconContextMenuOnClickListener() {
public void onClick(int menuId) {
switch(menuId) {
case MENU_ITEM_2_ACTION:
Toast.makeText(getApplicationContext(), "You've clicked normal line", Toast.LENGTH_SHORT).show();
myView.setNormalLine();
myView.setMode(1); //draw line
break;
case MENU_ITEM_4_ACTION:
Toast.makeText(getApplicationContext(), "You've clicked dashed line", Toast.LENGTH_SHORT).show();
myView.setDashLine();
myView.setMode(2);//draw dashed line
break;
}
}
});
iconContextMenuShapes = new IconContextMenu(this, CONTEXT_MENU_SHAPES_ID);
iconContextMenuShapes.addItem(res, "", R.drawable.cerc,MENU_ITEM_1_ACTION);
iconContextMenuShapes.addItem(res, "",R.drawable.square, MENU_ITEM_2_ACTION);
iconContextMenuShapes.setOnClickListener(new IconContextMenu.IconContextMenuOnClickListener() {
public void onClick(int menuId) {
switch(menuId) {
case MENU_ITEM_1_ACTION:
Toast.makeText(getApplicationContext(), "You've clicked circle", Toast.LENGTH_SHORT).show();
myView.setMode(4); //draw circle
break;
case MENU_ITEM_2_ACTION:
Toast.makeText(getApplicationContext(), "You've clicked rectangle", Toast.LENGTH_SHORT).show();
myView.setMode(5); //draw rectangle
break;
}
}
});
iconContextMenuColors = new IconContextMenu(this, CONTEXT_MENU_SHAPES_ID);
iconContextMenuColors.addItem(res, "", R.drawable.red,MENU_ITEM_1_ACTION);
iconContextMenuColors.addItem(res, "",R.drawable.green, MENU_ITEM_2_ACTION);
iconContextMenuColors.addItem(res, "",R.drawable.blue, MENU_ITEM_3_ACTION);
iconContextMenuColors.addItem(res, "", R.drawable.magenta,MENU_ITEM_4_ACTION);
iconContextMenuColors.addItem(res, "",R.drawable.yellow, MENU_ITEM_5_ACTION);
iconContextMenuColors.addItem(res, "",R.drawable.white, MENU_ITEM_6_ACTION);
iconContextMenuColors.addItem(res, "", R.drawable.black,MENU_ITEM_7_ACTION);
iconContextMenuColors.addItem(res, "", R.drawable.black,MENU_ITEM_8_ACTION);
iconContextMenuColors.setOnClickListener(new IconContextMenu.IconContextMenuOnClickListener() {
public void onClick(int menuId) {
switch(menuId) {
case MENU_ITEM_1_ACTION:
Toast.makeText(getApplicationContext(), "Red", Toast.LENGTH_SHORT).show();
myView.changeColor(Color.RED);
break;
case MENU_ITEM_2_ACTION:
Toast.makeText(getApplicationContext(), "Green", Toast.LENGTH_SHORT).show();
myView.changeColor(Color.GREEN);
break;
case MENU_ITEM_3_ACTION:
Toast.makeText(getApplicationContext(), "Blue", Toast.LENGTH_SHORT).show();
myView.changeColor(Color.BLUE);
break;
case MENU_ITEM_4_ACTION:
Toast.makeText(getApplicationContext(), "Magenta", Toast.LENGTH_SHORT).show();
myView.changeColor(Color.MAGENTA);
break;
case MENU_ITEM_5_ACTION:
Toast.makeText(getApplicationContext(), "Yellow", Toast.LENGTH_SHORT).show();
myView.changeColor(Color.YELLOW);
break;
case MENU_ITEM_6_ACTION:
Toast.makeText(getApplicationContext(), "White", Toast.LENGTH_SHORT).show();
myView.changeColor(Color.WHITE);
break;
case MENU_ITEM_7_ACTION:
Toast.makeText(getApplicationContext(), "Black", Toast.LENGTH_SHORT).show();
myView.changeColor(Color.BLACK);
break;
case MENU_ITEM_8_ACTION:
Toast.makeText(getApplicationContext(), "Blue", Toast.LENGTH_SHORT).show();
myView.changeColor(Color.BLUE);
break;
}
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.first_activity, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item){
switch (item.getItemId()) {
case R.id.tools:
ll.setVisibility(LinearLayout.VISIBLE);
return true;
case R.id.import_pics:
getPhotos();
return true;
case R.id.save:
toJPEGFile();
return true;
case R.id.trash:
clearPoints();
return true;
}
return false;
}
public void clearPoints () {
forceRedraw();
}
public void forceRedraw() {
invalidate();
}
private void toJPEGFile() {
// TODO Auto-generated method stub
String root = Environment.getExternalStorageDirectory().toString();
File myDir = new File(root + "/saved_images");
myDir.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "Image-"+ n +".jpg";
File file = new File (myDir, fname);
if (file.exists ()) file.delete ();
try {
FileOutputStream out = new FileOutputStream(file);
Bitmap finalBitmap = CanvasView.bitmap;
finalBitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
out.flush();
out.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public void getPhotos(){
Intent photoPickerIntent = new Intent(Intent.ACTION_GET_CONTENT);
photoPickerIntent.setType("image/*");
startActivityForResult(photoPickerIntent, 1);
}
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK)
{
Uri chosenImageUri = data.getData();
Toast.makeText(getApplicationContext(), "Photo background added!", Toast.LENGTH_SHORT).show();
Bitmap mBitmap = null;
try {
mBitmap = Media.getBitmap(this.getContentResolver(), chosenImageUri);
if(mBitmap.isMutable())
Toast.makeText(getApplicationContext(), "is mutable", Toast.LENGTH_SHORT).show();
//cView = new MyCustomView(getApplicationContext(), null);
myView.setImage(mBitmap);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
public void colorChanged(int color) {
mPaint.setColor(color);
}
}
在这里你有 CanvasView.java
public class CanvasView extends View{
private ArrayList<Path> undonePaths = new ArrayList<Path>();
private ArrayList<Path> paths = new ArrayList<Path>();
private static final float STROKE_WIDTH = 5f;
private static final float HALF_STROKE_WIDTH = STROKE_WIDTH/2;
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
Paint erasePaint = new Paint();
Paint paint = new Paint();
Path path = new Path();
float lastTouchX,lastTouchY;
AlertDialog.Builder alert;
RectF ovalRectangle = new RectF();
RectF dirtyRect = new RectF();
MyRectangle myRectangle;
MyOval myOval;
MyCircle myCircle;
MyFreehand myFreehand;
MyLine myLine;
MyEraser myEraser;
List<MyEraser> eraserList = new ArrayList<MyEraser>();
List<MyLine> lineList = new ArrayList<MyLine>();
List<MyFreehand> freehandList = new ArrayList<MyFreehand>();
List<MyCircle> circleList = new ArrayList<MyCircle>();
List<MyOval> ovalList = new ArrayList<MyOval>();
List<MyRectangle> rectangleList = new ArrayList<MyRectangle>();
public boolean dashedLine = false;
public DashPathEffect dashEffect = new DashPathEffect(new float[]{20,30}, 0);
private Paint mBitmapPaint;
private Bitmap mBitmap;
public String textValue;
public CanvasView(Context context, AttributeSet attrs) {
super(context, attrs);
setBackgroundColor(Color.WHITE);
if (android.os.Build.VERSION.SDK_INT >= 11)
{
turnOffHardwareAcc();
}
erasePaint.setColor(Color.TRANSPARENT);
//erasePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
erasePaint.setAntiAlias(true);
erasePaint.setStyle(Paint.Style.STROKE);
erasePaint.setStrokeJoin(Paint.Join.ROUND);
erasePaint.setStrokeWidth(5f);
paint.setColor(Color.BLACK);
paint.setStyle(Paint.Style.STROKE);
paint.setAntiAlias(true);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeWidth(STROKE_WIDTH);
paint.setTextSize(72);
setMode(7);//default = 7 - free hand;
mBitmap = Bitmap.createBitmap(320, 480, Bitmap.Config.ARGB_8888);
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
/* input dialog*/
//setInputDialog();
}
EditText input;
public void setInputDialog(){
alert = new AlertDialog.Builder(getContext());
alert.setTitle("Title");
alert.setMessage("Write text");
// Set an EditText view to get user input
input = new EditText(getContext());
alert.setView(input);
alert.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
textValue= input.getText().toString();
Toast.makeText(getContext(), textValue, Toast.LENGTH_SHORT).show();
// Do something with value!
}
});
alert.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
// Canceled.
}
});
//alert.show();
}
private void touch_start(float x, float y) {
undonePaths.clear();
path.reset();
path.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
path.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
}
private void touch_up() {
path.lineTo(mX, mY);
Canvas mCanvas = null;
// commit the path to our offscreen
mCanvas.drawPath(path, paint);
// kill this so we don't double draw
paths.add(path);
path = new Path();
}
public void Undo () {
if (paths.size()>0) {
undonePaths.add(paths.remove(paths.size()-1));
invalidate();
}
else
{
}
}
public void Redo (){
if (undonePaths.size()>0) {
paths.add(undonePaths.remove(undonePaths.size()-1));
invalidate();
}
else
{
}
}
public void setDashLine(){
dashedLine = true;
paint = new Paint();
paint.setPathEffect(dashEffect);
paint.setStyle(Paint.Style.STROKE);
paint.setAntiAlias(true);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeWidth(STROKE_WIDTH);
}
public void setNormalLine(){
//paint.setColor(Color.BLACK);
dashedLine = false;
paint.setPathEffect(null);
paint.setStyle(Paint.Style.STROKE);
paint.setPathEffect(null);
paint.setAntiAlias(true);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeWidth(STROKE_WIDTH);
}
@TargetApi(11)
public void turnOffHardwareAcc() // to enable dashed lines
{
this.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
}
//public void setPaint(int color,)
@TargetApi(11)
protected void onDraw(Canvas canvas) {
paint.setPathEffect(null);
if(bitmap!=null){
canvas.drawBitmap(bitmap, 0, 0, paint);
for(MyCircle circle:circleList){// draw circles
myCanvas.drawCircle(getCircleMidPointX(circle.firstX, circle.lastX),getCircleMidPointY(circle.firstY, circle.lastY),circle.radius,myPaint);
}
}
for(MyLine line:lineList){ //draw lines
if(dashedLine)
line.paint.setPathEffect(dashEffect);
else
line.paint.setPathEffect(null);
canvas.drawLine(line.xStart, line.yStart, line.xEnd, line.yEnd, line.paint);
}
for(MyCircle circle:circleList){// draw circles
canvas.drawCircle(getCircleMidPointX(circle.firstX, circle.lastX),getCircleMidPointY(circle.firstY, circle.lastY),circle.radius,paint);
}
for(MyOval oval:ovalList){
oval.paint.setPathEffect(null);
ovalRectangle.set(oval.getX1(),oval.getY1(),oval.getX2(),oval.getY2());
canvas.drawOval(ovalRectangle, oval.paint);
}
for(MyRectangle rectangle:rectangleList){
rectangle.paint.setPathEffect(null);
canvas.drawRect(rectangle.getX1(),rectangle.getY1(),rectangle.getX2(),rectangle.getY2(),rectangle.paint);
}
for(MyEraser e:eraserList){
canvas.drawPath(e.p,erasePaint);
invalidate();
}
if(textValue!= null)
canvas.drawText(textValue, xStart, yStart, paint);
canvas.drawPath(path, paint);
//path.reset();
}
public boolean onTouch(View arg0, MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
}
return true;
}
final OnTouchListener drawLineListener = new OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
FirstActivity.ll.setVisibility(LinearLayout.GONE);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
myLine = new MyLine();
myLine.xStart = event.getX();
myLine.yStart = event.getY();
return true;
case MotionEvent.ACTION_MOVE:
case MotionEvent.ACTION_UP:
myLine.xEnd = event.getX();
myLine.yEnd = event.getY();
invalidate();
lineList.add(myLine);
break;
default:
Log.d("mock it up", "Unknown touch event " + event.toString());
return false;
}
return true;
}
};
final OnTouchListener drawDashedLineListener = new OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
FirstActivity.ll.setVisibility(LinearLayout.GONE);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
return true;
case MotionEvent.ACTION_MOVE:
case MotionEvent.ACTION_UP:
break;
default:
Log.d("mock it up", "Unknown touch event " + event.toString());
return false;
}
return true;
}
};
final OnTouchListener drawCircleListener = new OnTouchListener(){
public boolean onTouch(View v, MotionEvent event) {
FirstActivity.ll.setVisibility(LinearLayout.GONE);
float eventX = event.getX();
float eventY = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
// path.moveTo(eventX, eventY);
Toast.makeText(getContext(), "action down - circle",Toast.LENGTH_SHORT).show();
myCircle = new MyCircle();
myCircle.firstX = eventX;
myCircle.firstY = eventY;
// There is no end point yet, so don't waste cycles invalidating.
return true;
case MotionEvent.ACTION_MOVE:
case MotionEvent.ACTION_UP:
myCircle.lastX = eventX;
myCircle.lastY = eventY;
myCircle.radius = getRadius(myCircle.firstX,myCircle.firstY,myCircle.lastX,myCircle.lastY);
circleList.add(myCircle);
invalidate();
break;
default:
Log.d("mock it up", "Unknown touch event " + event.toString());
return false;
}
return true;
}
};
final OnTouchListener drawOvalListener = new OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
FirstActivity.ll.setVisibility(LinearLayout.GONE);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
myOval = new MyOval();
myOval.setX1(event.getX());
myOval.setY1(event.getY());
// There is no end point yet, so don't waste cycles invalidating.
return true;
case MotionEvent.ACTION_MOVE:
case MotionEvent.ACTION_UP:
myOval.setX2(event.getX());
myOval.setY2(event.getY());
invalidate();
ovalList.add(myOval);
default:
Log.d("mock it up", "Unknown touch event " + event.toString());
return false;
}
}
};
final OnTouchListener drawRectangleListener = new OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
FirstActivity.ll.setVisibility(LinearLayout.GONE);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
myRectangle = new MyRectangle();
myRectangle.setX1(event.getX());
myRectangle.setY1(event.getY());
return true;
case MotionEvent.ACTION_MOVE:
case MotionEvent.ACTION_UP:
myRectangle.setX2(event.getX());
myRectangle.setY2(event.getY());
invalidate();
rectangleList.add(myRectangle);
break;
default:
Log.d("mock it up", "Unknown touch event " + event.toString());
return false;
}
return true;
}
};
final OnTouchListener eraseListener = new OnTouchListener() {
};
final OnTouchListener drawFreeHandListener = new OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
FirstActivity.ll.setVisibility(LinearLayout.GONE);
float eventX = event.getX();
float eventY = event.getY();
// Include half the stroke width to avoid clipping.
invalidate(
(int) (dirtyRect.left - HALF_STROKE_WIDTH),
(int) (dirtyRect.top - HALF_STROKE_WIDTH),
(int) (dirtyRect.right + HALF_STROKE_WIDTH),
(int) (dirtyRect.bottom + HALF_STROKE_WIDTH));
lastTouchX = eventX;
lastTouchY = eventY;
return true;
}
};
float xStart,yStart;
final OnTouchListener textListener = new OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
FirstActivity.ll.setVisibility(LinearLayout.GONE);
// Toast.makeText(getContext(), "add some text", Toast.LENGTH_SHORT).show();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
//
setInputDialog();
xStart = event.getX();
yStart = event.getY();
alert.show();
break;
case MotionEvent.ACTION_MOVE:
case MotionEvent.ACTION_UP:
// setInputDialog();
break;
default:
Log.d("mock it up", "Unknown touch event " + event.toString());
return false;
}
return true;
}
};
/**
* Called when replaying history to ensure the dirty region includes all
* points.
*/
private void expandDirtyRect(float historicalX, float historicalY) {
if (historicalX < dirtyRect.left) {
dirtyRect.left = historicalX;
} else if (historicalX > dirtyRect.right) {
dirtyRect.right = historicalX;
}
if (historicalY < dirtyRect.top) {
dirtyRect.top = historicalY;
} else if (historicalY > dirtyRect.bottom) {
dirtyRect.bottom = historicalY;
}
}
/**
* Resets the dirty region when the motion event occurs.
*/
private void resetDirtyRect(float eventX, float eventY) {
// The lastTouchX and lastTouchY were set when the ACTION_DOWN
// motion event occurred.
dirtyRect.left = Math.min(lastTouchX, eventX);
dirtyRect.right = Math.max(lastTouchX, eventX);
dirtyRect.top = Math.min(lastTouchY, eventY);
dirtyRect.bottom = Math.max(lastTouchY, eventY);
}
public void setMode(int mode){
switch(mode){
case 1://draw line
Toast.makeText(getContext(), "draw line", Toast.LENGTH_SHORT).show();
setOnTouchListener(drawLineListener);
break;
case 2://draw dashed line
Toast.makeText(getContext(), "dashed line", Toast.LENGTH_SHORT).show();
break;
case 3:// draw circle
setOnTouchListener(drawCircleListener);
break;
case 4: //draw oval
setOnTouchListener(drawOvalListener);
break;
case 5: //draw rectangle
setOnTouchListener(drawRectangleListener);
break;
case 6: //erase
setOnTouchListener(eraseListener);
break;
case 7: //free-hand
setOnTouchListener(drawFreeHandListener);
break;
case 8:
setOnTouchListener(textListener);
break;
}
}
static Bitmap bitmap;
private Canvas myCanvas;
public Paint myPaint;
public void setImage(Bitmap b){
Toast.makeText(getContext(), "set Bitmap",Toast.LENGTH_SHORT).show();
bitmap = b.copy(Bitmap.Config.ARGB_8888, true);
myCanvas = new Canvas(bitmap);
myPaint = new Paint();
myPaint.setColor(Color.YELLOW);
myPaint.setAntiAlias(true);
myPaint.setStrokeWidth(8);
invalidate();
}
public void changeColor(int color){
paint = new Paint(paint);
paint.setColor(color);
//myPaint.setColor(color);
}
public float getRadius(float x1,float y1,float x2,float y2){
float r = (float) (Math.sqrt((double)(Math.pow((y2-y1), 2.0)+Math.pow((x2-x1), 2.0)))/2);
return r;
}
public float getCircleMidPointX(float x1,float x2){
return (x1+x2)/2;
}
public float getCircleMidPointY(float y1,float y2){
return (y1+y2)/2;
}
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(mBitmap);
canvas.drawColor(Color.GREEN);
super.onSizeChanged(w, h, oldw, oldh);
}
}
我附上了我的代码，以便更有用地了解我的问题在哪里。希望您能够帮助我。先感谢您 ：）