Android 未在自定义视图中绘制位图
我有一个应用程序，可以从SD卡上的摄像头和存储中捕获图片。我已经创建了一个自定义视图，将该图像读取到一个数组中，并从中创建位图。我已经使用bitmap.createBitmap（w，h，config）从原始位图创建了另一个位图，因此我有一个可变副本。在我的视图的onDraw中，没有绘制位图，只显示一个黑色图像。你知道为什么没有绘制位图吗？谢谢Android 未在自定义视图中绘制位图,android,graphics,bitmap,Android,Graphics,Bitmap,我有一个应用程序，可以从SD卡上的摄像头和存储中捕获图片。我已经创建了一个自定义视图，将该图像读取到一个数组中，并从中创建位图。我已经使用bitmap.createBitmap（w，h，config）从原始位图创建了另一个位图，因此我有一个可变副本。在我的视图的onDraw中，没有绘制位图，只显示一个黑色图像。你知道为什么没有绘制位图吗？谢谢 BitmapFactory.Options bfo = new BitmapFactory.Options(); bfo.inSa
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());
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);
}
}
}
您正在创建相同大小的全新可变
位图，而不是创建可变副本
尝试使用：
true
参数表示您需要可变副本。是否使视图无效？@jett我没有使用布局文件，我已将活动的setContentView设置为指向自定义视图。抱歉，如果我误解了。@matthew willis嗨，不，我很抱歉bgr位图仍然设置为黑色。我已检查bgr是否为空，是否创建了位图对象04-06 20:02:58.746:bgr=android.graphics。Bitmap@43e6e188turtleboy,你能试着在你的onDraw中绘制一个已知的好位图，以确保绘制代码本身没有问题吗？@matthew willis我已经加载了一个图标图片，它绘制得很好。我使用了一个可绘制的工具，例如bgr=BitmapFactory.decodeResource（getResources（），R.drawable.icon）；看起来copy
正在工作，您的字节数组可能一开始是空的。
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);
}
}
}
bgr = bm.copy(bm.getConfig(), true);