我正在制作一个应用程序，我无法在过去 3 天尽可能多地使用 google。我在画布上画了一个圆圈，想要裁剪该部分的图像并以缩放模式显示该图像。我的第一步就像在这里的屏幕中一样： -
在这个我选择区域。这是我为此使用的代码。
private float x, y;
private boolean zooming = false;
private Paint mPaint;
private Matrix mmatrix;
private Shader mShader;
private Bitmap mBitmap;
private List<Point> mpoints;
private List<MyPoints> mpointlist;
private Path mpath;
private Canvas mcanvas;
private Bitmap mresult_bitmap, resultingImage,finalbitmap;
private Context mcontext;
private boolean bfirstpoint = false;
private Point mfirstpoint = null;
private Point mlastpoint = null;
public CircularZoomView(Context context) {
super(context);
mcontext = context;
mpath = new Path();
mpoints = new ArrayList<Point>();
setBackgroundResource(R.drawable.testing);
mPaint = new Paint();
mresult_bitmap = BitmapFactory.decodeResource(getResources(),
R.drawable.testing);
mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setPathEffect(new DashPathEffect(new float[] { 10, 20 }, 0));
mPaint.setStrokeWidth(5);
mPaint.setColor(Color.RED);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (zooming && resultingImage!=null) {
zooming = false;
ShowImage(resultingImage);
canvas.drawBitmap(resultingImage,mmatrix, null);
}
boolean first = true;
for (int i = 0; i < mpoints.size(); i += 2) {
Point point = mpoints.get(i);
if (first) {
first = false;
mpath.moveTo(point.x, point.y);
} else if (i < mpoints.size() - 1) {
Point next = mpoints.get(i + 1);
mpath.quadTo(point.x, point.y, next.x, next.y);
} else {
mlastpoint = mpoints.get(i);
mpath.lineTo(point.x, point.y);
}
}
canvas.drawPath(mpath, mPaint);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
int action = event.getAction();
x = event.getX();
y = event.getY();
Point point = new Point();
point.x = (int) event.getX();
point.y = (int) event.getY();
if (bfirstpoint) {
if (comparepoint(mfirstpoint, point)) {
mpoints.add(mfirstpoint);
addCircleFromPath(mpath);
} else {
mpoints.add(point);
}
} else {
mpoints.add(point);
}
if (!(bfirstpoint)) {
mfirstpoint = point;
bfirstpoint = true;
}
invalidate();
switch (action) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_MOVE:
zooming = false;
this.invalidate();
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
zooming = true;
mlastpoint = point;
if (mpoints.size() > 12) {
if (!comparepoint(mfirstpoint, mlastpoint)) {
mpoints.add(mfirstpoint);
addCircleFromPath(mpath);
}
}
this.invalidate();
break;
default:
break;
}
return true;
}
public Bitmap getCroppedBitmap(Bitmap bitmap) {
Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
bitmap.getHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final int color = 0xff424242;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawCircle(bitmap.getWidth() / 2, bitmap.getHeight() / 2,
bitmap.getWidth() / 2, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);
return output;
}
void ShowImage(Bitmap mbitmap) {
Display display = ((MainActivity) mcontext).getWindowManager().getDefaultDisplay();
int screenWidth = display.getWidth();
float imageWidth = (float)mbitmap.getWidth();
float imageHeight = (float)mbitmap.getHeight();
float newHeight = imageHeight / (imageWidth / screenWidth);
float newWidth = screenWidth;
float scaleWidth = screenWidth / imageWidth;
float scaleHeight = newHeight / imageHeight;
SetImageMatrix(mbitmap,scaleWidth,scaleHeight);
}
void SetImageMatrix(Bitmap image,float scaleWidth, float scaleHeight) {
mmatrix = new Matrix();
mmatrix.setTranslate(40,40);
mmatrix.postScale(scaleWidth/2, scaleHeight/2);
/*image.setImageMatrix(mmatrix);
image.setScaleType(ScaleType.MATRIX);
image.invalidate();*/
}
private boolean comparepoint(Point first, Point current) {
int left_range_x = (int) (current.x - 3);
int left_range_y = (int) (current.y - 3);
int right_range_x = (int) (current.x + 3);
int right_range_y = (int) (current.y + 3);
if ((left_range_x < first.x && first.x < right_range_x)
&& (left_range_y < first.y && first.y < right_range_y)) {
if (mpoints.size() < 10) {
return false;
} else {
return true;
}
} else {
return false;
}
}
private void addCircleFromPath(Path path){
RectF bounds = new RectF();
path.computeBounds(bounds, true);
int width = (int) (bounds.right-bounds.left);
int height = (int) (bounds.bottom-bounds.top);
if(width<20 && height<20){
path.reset();
return;
}
int radius ;
if(width>=height)
radius = Math.round(((width/2)));
else radius = Math.round((int) ((height/2)));
/*CircleTagObject circle = new CircleTagObject((int)bounds.left+width/2, (int)bounds.top+height/2, radius, crossBitmap, tagBitmap,circleArray.size(),
ImageEditorView.this);
circleArray.add(circle);
tagBallID = circleArray.size() - 1;
dragEnable = true;*/
resultingImage = getCroppedBitmap(Bitmap.createBitmap(mresult_bitmap,0,0,200,200));
mcanvas = new Canvas(resultingImage);
path.reset();
resetView();
invalidate();
}
public void resetView() {
mpoints.clear();
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setPathEffect(new DashPathEffect(new float[] { 10, 20 }, 0));
mPaint.setStrokeWidth(5);
mPaint.setColor(Color.RED);
invalidate();
}
如果我创建像上面这样的硬编码位图，它显示良好但不裁剪所选部分的位图。就像这张图片。
但是当添加所选区域的精确坐标时，例如：-
resultingImage = getCroppedBitmap(Bitmap.createBitmap(mresult_bitmap,(int)bounds.left,(int)bounds.top,width,height));
然后发生异常：-
07-12 10:58:56.700: E/MessageQueue-JNI(12310): java.lang.IllegalArgumentException: y + height must be <= bitmap.height()
07-12 10:58:56.700: E/MessageQueue-JNI(12310): at android.graphics.Bitmap.createBitmap(Bitmap.java:565)
07-12 10:58:56.700: E/MessageQueue-JNI(12310): at android.graphics.Bitmap.createBitmap(Bitmap.java:530)
07-12 10:58:56.700: E/MessageQueue-JNI(12310): at com.intel.view.CircularZoomView.addCircleFromPath(CircularZoomView.java:237)
我知道为什么会发生此异常，但无法找到解决方案如何裁剪所选部分的图像。提前致谢。