我有一个应用程序可以从相机和存储在 SD 卡上的照片中捕捉照片。我创建了一个自定义 View ，该 View 将该图像读取到一个数组并从中创建一个位图。我使用 Bitmap.createBitmap(w,h,config) 从原始位图创建了另一个位图，这样我就有了一个可变副本。在我的 View onDraw 中，未绘制位图，仅显示黑色图像。为什么没有绘制位图的任何想法？谢谢
BitmapFactory.Options bfo = new BitmapFactory.Options();
bfo.inSampleSize = 1;
bm = BitmapFactory.decodeByteArray(imageArray, 0, imageArray.length, bfo);
bgr = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(), bm.getConfig());
在我的 onDraw() 中
@Override
public void onDraw(Canvas canvas){
super.onDraw(canvas);
Log.e(TAG, "***********BITMAP bm = "+bm.toString());
canvas.drawBitmap(bgr, 0, 0, null);
[编辑]
public class LoadPic2 extends Activity {
private static final String TAG = "*********LOADPIC";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.e(TAG, "***********inside oncreate about to set contentview = ");
setContentView(new TouchView(this));
}
class TouchView extends View{
private File tempFile;
private byte[] imageArray;
Bitmap bgr;
Bitmap bm;
Bitmap overlayRed;
Bitmap overlayBlue;
Paint pTouch;
int X = -100;
int Y = -100;
Canvas c2;
public TouchView(Context context) {
super(context);
Log.e(TAG, "***********inside Touchview constructor = ");
tempFile = new File(Environment.getExternalStorageDirectory().
getAbsolutePath() + "/"+"image.jpg");
imageArray = new byte[(int)tempFile.length()];
try{
InputStream is = new FileInputStream(tempFile);
BufferedInputStream bis = new BufferedInputStream(is);
DataInputStream dis = new DataInputStream(bis);
int i = 0;
while (dis.available() > 0) {
imageArray[i] = dis.readByte();
i++;
}
dis.close();
} catch (Exception e) {
e.printStackTrace();
}
Log.e(TAG, "***********end of touchview imagearray = "+ imageArray.length);
BitmapFactory.Options bfo = new BitmapFactory.Options();
bfo.inSampleSize = 1;
bm = BitmapFactory.decodeByteArray(imageArray, 0, imageArray.length, bfo);
bgr = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(), bm.getConfig());
bgr = bm.copy(bm.getConfig(), true);
// Log.e(TAG, "***********bgr = "+bgr.toString()+bgr);
overlayRed = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(), bm.getConfig());
overlayRed.eraseColor(Color.RED);
overlayBlue = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(), bm.getConfig());
overlayBlue.eraseColor(Color.BLUE);
// overlayRed = BitmapFactory.decodeResource(getResources(),R.drawable.icon);
// overlayBlue = BitmapFactory.decodeResource(getResources(),R.drawable.icon).copy(Config.ARGB_8888, true);
c2 = new Canvas(overlayBlue);//overlay
pTouch = new Paint(Paint.ANTI_ALIAS_FLAG);
pTouch.setXfermode(new PorterDuffXfermode(Mode.SRC_OUT));
pTouch.setColor(Color.TRANSPARENT);
pTouch.setMaskFilter(new BlurMaskFilter(15, Blur.NORMAL));
Log.e(TAG, "***********end of touchview constructor = "+bm.toString());
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN: {
X = (int) ev.getX();
Y = (int) ev.getY();
invalidate();
break;
}
case MotionEvent.ACTION_MOVE: {
X = (int) ev.getX();
Y = (int) ev.getY();
invalidate();
break;
}
case MotionEvent.ACTION_UP:
break;
}
return true;
}
@Override
public void onDraw(Canvas canvas){
super.onDraw(canvas);
Log.e(TAG, "***********BITMAP bm = "+bm.toString());
canvas.drawBitmap(bgr, 0, 0, null);
c2.drawBitmap(overlayRed, 0, 0, null); //exclude this line to show all as you draw
c2.drawCircle(X, Y, 80,pTouch);
canvas.drawBitmap(overlayBlue, 0, 0, null);
}
}
}
最佳答案
您正在创建一个全新的大小相同的可变位图，而不是制作一个可变副本。
尝试使用 Bitmap#copy :
bgr = bm.copy(bm.getConfig(), true);
true 参数表示您需要一个可变副本。
关于android - 未在自定义 View 中绘制位图，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/5570013/