我有以下类组成了我的应用程序，该应用程序在位图上放置了鱼眼扭曲。当我加载位图时，它仅在触摸屏幕或滑动条时显示，并且在 View 的构造函数完成后不显示位图。我在那里进行了一些日志记录，基本上调用了 ondraw() 但没有任何内容绘制到 Canvas 上。如何让应用程序在 View 构造函数完成后立即失效？
public class TouchView extends View{
private File tempFile;
private byte[] imageArray;
private Bitmap bgr;
private Bitmap bm;
private Bitmap bgr2 = null;;
private Paint pTouch;
private float centreX = 1;
private float centreY = 1;
private int radius = 50;
private int Progress = 1;
private static final String TAG = "*********TouchView";
private Filters f = null;
private boolean AsyncRunning = false;
// private MyTask mt = null;
public TouchView(Context context) {
super(context);
// TouchView(context, null);
}
public TouchView(Context context, AttributeSet attr) {
super(context,attr);
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();
}
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);
bgr2 = Bitmap.createBitmap(bm.getWidth(), bm.getHeight(), bm.getConfig());
f = new Filters();
pTouch = new Paint(Paint.ANTI_ALIAS_FLAG);
pTouch.setXfermode(new PorterDuffXfermode(Mode.SRC_OUT));
pTouch.setColor(Color.TRANSPARENT);
pTouch.setStyle(Paint.Style.STROKE);
Log.e(TAG, "++++++++++ end od touchview constructor");
}// end of touchView constructor
public void findCirclePixels(){
Log.e(TAG, "++++++++++ inside fpc");
new Thread(new Runnable() {
public void run() {
float prog = (float)Progress/150000;
final Bitmap bgr3 = f.barrel(bgr,prog,centreX,centreY);
TouchView.this.post(new Runnable() {
public void run() {
TouchView.this.bgr2 = bgr3;
TouchView.this.invalidate();
}
});
}
}).start();
/*
float prog = (float)Progress/150000;
long startTime = System.currentTimeMillis();
bgr2 = f.barrel(bgr,prog);
long endTime = System.currentTimeMillis();
long duration = endTime - startTime;
Log.e(TAG, "++++++++++ barrel() took "+ duration+" ms");
*/
Log.e(TAG, "++++++++++ end fpc");
}// end of changePixel()
@Override
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN: {
centreX = (int) ev.getX();
centreY = (int) ev.getY();
//findCirclePixels();
TouchView.this.invalidate();
break;
}
case MotionEvent.ACTION_MOVE: {
centreX = (int) ev.getX();
centreY = (int) ev.getY();
// findCirclePixels();
TouchView.this.invalidate();
break;
}
case MotionEvent.ACTION_UP:
break;
}
return true;
}//end of onTouchEvent
public void initSlider(final HorizontalSlider slider)
{
Log.e(TAG, "******setting up slider*********** ");
slider.setOnProgressChangeListener(changeListener);
}
private OnProgressChangeListener changeListener = new OnProgressChangeListener() {
@Override
public void onProgressChanged(View v, int progress) {
// TODO Auto-generated method stub
setProgress(progress);
//TouchView.this.Progress = progress;
}
};
@Override
public void onDraw(Canvas canvas){
super.onDraw(canvas);
Log.e(TAG, "++++++++++ inside ondraw");
canvas.drawBitmap(bgr2, 0, 0, null);
// canvas.drawCircle(centreX, centreY, radius,pTouch);
Log.e(TAG, "++++++++++end ondraw");
}//end of onDraw
protected void setProgress(int progress2) {
Log.e(TAG, "***********in SETPROGRESS");
this.Progress = progress2;
findCirclePixels();
invalidate();
}
}
最佳答案
位图 bgr2 在构造函数中创建，但其中没有绘制。它将通过 findCirclePixels 进行绘制，在 slider 更改时调用该函数。
我认为createBitmap(int width, int height, Bitmap.Config config)仅使用config，您可以使用其他变体创建位图
Bitmap createBitmap (Bitmap source, int x, int y, int width, int height)
关于java - 如何强制invalidate()？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/6471570/