java - 旋转手机时 DrawerView 正在清除
问题描述
当我旋转手机时,我DrawerView
正在清除。当我在课堂DrawerView
上旋转我的手机时onSizeChanged
,我的 drawView 是空的。我已android:configChanges="keyboardHidden|orientation|screenSize"
在我的 AndroidManifest 中添加,但它不起作用。
这是我的抽屉视图:
public class DrawerView extends View {
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
private float mX, mY, sX, sY;
private boolean isSigned = false;
public DrawerView(Context c) {
super(c);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mBitmapPaint.setColor(Color.WHITE);
}
public DrawerView(Context c, Bitmap bitmap) {
super(c);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mBitmapPaint.setColor(Color.WHITE);
mBitmap = bitmap;
}
public void setIsSigned(boolean isSigned) {
this.isSigned = isSigned;
}
public boolean isSigned() {
return isSigned;
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.RGB_565);
mCanvas = new Canvas(mBitmap);
mCanvas.drawColor(Color.WHITE);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
}
public void clear() {
setDrawingCacheEnabled(true);
mCanvas.drawColor(Color.WHITE);
invalidate();
}
private void drawDot(float x, float y) {
mCanvas.drawCircle(x, y, 2.0f, mPaint);
}
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
sX = x;
sY = y;
}
private void touch_move(float x, float y) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
mCanvas.drawPath(mPath, mPaint);
}
private void touch_up() {
mPath.lineTo(mX, mY);
mCanvas.drawPath(mPath, mPaint);
mPath.reset();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
this.isSigned = true;
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
break;
case MotionEvent.ACTION_UP:
if (x == sX && y == sY) {
drawDot(x, y);
}
touch_up();
break;
}
invalidate();
return true;
}
}
当我旋转手机时,这是在做
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.RGB_565);
mCanvas = new Canvas(mBitmap);
mCanvas.drawColor(Color.WHITE);
}
我的抽屉正在清理
这是我的全班:
公共类 SignatureActivity 扩展 Activity 实现 Handler.Callback {
File mCurrentPhotoPath;
private FrameLayout drawerBox;
private Button save, clear;
private DrawerView mv;
private Paint mPaint;
private boolean existingSign;
private Intent intent;
private String signature;
private File imagesDir;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.drawer_act_lay);
existingSign = getIntent().hasExtra(getPackageName() + "_signaturePath");
initializeView();
setListeners();
Intent iin = getIntent();
Bundle b = iin.getExtras();
if (b != null) {
signature = (String) b.get("signaturePath");
}
}
@Override
protected void onResume() {
super.onResume();
}
@Override
protected void onDestroy() {
super.onDestroy();
}
@Override
public void onBackPressed() {
setResult(RESULT_CANCELED);
finish();
}
private void initializeView() {
drawerBox = this.findViewById(R.id.drawerContainer);
save = findViewById(R.id.saveBtn);
clear = findViewById(R.id.clearBtn);
if (existingSign) {
mv = new DrawerView(this, BitmapFactory.decodeFile(getIntent()
.getStringExtra(getPackageName() + "_signaturePath")));
} else {
mv = new DrawerView(this);
}
mv.setDrawingCacheEnabled(false);
mv.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT));
drawerBox.addView(mv);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(Color.BLACK);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(3);
mv.setDrawingCacheEnabled(true);
}
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
mCurrentPhotoPath = (File) savedInstanceState.getSerializable(MY_CURRENT_PHOTO_PATH_KEY);
super.onRestoreInstanceState(savedInstanceState);
}
@Override
protected void onSaveInstanceState(Bundle outState) {
outState.putSerializable(MY_CURRENT_PHOTO_PATH_KEY, mCurrentPhotoPath);
super.onSaveInstanceState(outState);
}
private void setListeners() {
save.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (!mv.isSigned()) {
Toast.makeText(SignatureActivity.this, R.string.empty_sign, Toast.LENGTH_SHORT).show();
} else {
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmss", Locale.US);
String currentDateandTime = sdf.format(new Date());
String name = "sign_" + currentDateandTime;
Bitmap bitmap = mv.getDrawingCache();
File imagesFolder = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
imagesFolder.mkdirs();
File file = new File(imagesFolder, name + ".jpg");
try {
if (!file.exists()) {
file.createNewFile();
}
FileOutputStream ostream = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 80, ostream);
ostream.close();
mv.invalidate();
} catch (Exception e) {
e.printStackTrace();
} finally {
mv.setDrawingCacheEnabled(true);
}
Intent data = new Intent();
data.putExtra(getPackageName() + "_signaturePath", file.getPath());
setResult(RESULT_OK, data);
finishWithResult(file.getPath());
if (signature != null) {
File file1 = new File(signature);
file1.delete();
}
}
}
});
clear.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
mv.clear();
mv.setIsSigned(false);
}
});
}
private void finishWithResult(String path) {
Intent intent = new Intent();
setResult(RESULT_OK, intent);
intent.putExtra("path", path);
finish();
}
@Override
public boolean handleMessage(Message msg) {
return false;
}
public class DrawerView extends View {
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
private float mX, mY, sX, sY;
private boolean isSigned = false;
public DrawerView(Context c) {
super(c);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mBitmapPaint.setColor(Color.WHITE);
}
public DrawerView(Context c, Bitmap bitmap) {
super(c);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mBitmapPaint.setColor(Color.WHITE);
mBitmap = bitmap;
}
public void setIsSigned(boolean isSigned) {
this.isSigned = isSigned;
}
public boolean isSigned() {
return isSigned;
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.RGB_565);
mCanvas = new Canvas(mBitmap);
mCanvas.drawColor(Color.WHITE);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
}
public void clear() {
setDrawingCacheEnabled(true);
mCanvas.drawColor(Color.WHITE);
invalidate();
}
private void drawDot(float x, float y) {
mCanvas.drawCircle(x, y, 2.0f, mPaint);
}
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
sX = x;
sY = y;
}
private void touch_move(float x, float y) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
mCanvas.drawPath(mPath, mPaint);
}
private void touch_up() {
mPath.lineTo(mX, mY);
mCanvas.drawPath(mPath, mPaint);
mPath.reset();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
this.isSigned = true;
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
break;
case MotionEvent.ACTION_UP:
if (x == sX && y == sY) {
drawDot(x, y);
}
touch_up();
break;
}
invalidate();
return true;
}
}
}
解决方案
您可以将触摸事件保存在某种类型的列表中,然后在配置更改后重新创建它们。这已经在这里解释过了。
你的班级应该是这样的
public class DrawerView extends View {
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
private float mX, mY, sX, sY;
private boolean isSigned = false;
private static final String EXTRA_STATE = "exta_state";
private static final String EXTRA_EVENT_LIST = "exta_event_list";
private ArrayList<MotionEvent> motionEvents = new ArrayList<>();
private ArrayList<MotionEvent> auxMotionEvents = new ArrayList<>();
public DrawerView(Context c) {
super(c);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mBitmapPaint.setColor(Color.WHITE);
setSaveEnabled(true);
}
public DrawerView(Context c, AttributeSet attributeSet) {
super(c, attributeSet);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mBitmapPaint.setColor(Color.WHITE);
setSaveEnabled(true);
}
public DrawerView(Context c, Bitmap bitmap) {
super(c);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mBitmapPaint.setColor(Color.WHITE);
mBitmap = bitmap;
setSaveEnabled(true);
}
@Override
public Parcelable onSaveInstanceState() {
Bundle bundle = new Bundle();
bundle.putParcelable(EXTRA_STATE, super.onSaveInstanceState());
bundle.putParcelableArrayList(EXTRA_EVENT_LIST, motionEvents);
return bundle;
}
@Override
public void onRestoreInstanceState(Parcelable state) {
if (state instanceof Bundle) {
auxMotionEvents = new ArrayList<>();
motionEvents = new ArrayList<>();
Bundle bundle = (Bundle) state;
super.onRestoreInstanceState(bundle.getParcelable(EXTRA_STATE));
auxMotionEvents = bundle.getParcelableArrayList(EXTRA_EVENT_LIST);
if (auxMotionEvents == null) {
auxMotionEvents = new ArrayList<>();
}
return;
}
super.onRestoreInstanceState(state);
}
private void performTouch(MotionEvent event) {
this.isSigned = true;
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
break;
case MotionEvent.ACTION_UP:
if (x == sX && y == sY) {
drawDot(x, y);
}
touch_up();
break;
}
invalidate();
motionEvents.add(MotionEvent.obtain(event));
}
public void setIsSigned(boolean isSigned) {
this.isSigned = isSigned;
}
public boolean isSigned() {
return isSigned;
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.RGB_565);
mCanvas = new Canvas(mBitmap);
mCanvas.drawColor(Color.WHITE);
if (auxMotionEvents != null) {
for (MotionEvent motionEvent : auxMotionEvents) {
performTouch(motionEvent);
}
}
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mBitmapPaint);
}
public void clear() {
setDrawingCacheEnabled(true);
mCanvas.drawColor(Color.WHITE);
invalidate();
}
private void drawDot(float x, float y) {
mCanvas.drawCircle(x, y, 2.0f, mBitmapPaint);
}
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
sX = x;
sY = y;
}
private void touch_move(float x, float y) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
mCanvas.drawPath(mPath, mBitmapPaint);
}
private void touch_up() {
mPath.lineTo(mX, mY);
mCanvas.drawPath(mPath, mBitmapPaint);
mPath.reset();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_MOVE:
case MotionEvent.ACTION_UP:
performTouch(event);
}
return true;
}
}
请记住从清单中删除 android:configChanges="keyboardHidden|orientation|screenSize" 并为视图提供一个 ID,以便可以重新创建它。
在您的 initializeView() 中实例化 DrawerView 后,要为您的视图设置一个 ID,请使用 setId()。它应该看起来像这样
private void initializeView() {
drawerBox = this.findViewById(R.id.drawerContainer);
save = findViewById(R.id.saveBtn);
clear = findViewById(R.id.clearBtn);
if (existingSign) {
mv = new DrawerView(this, BitmapFactory.decodeFile(getIntent()
.getStringExtra(getPackageName() + "_signaturePath")));
} else {
mv = new DrawerView(this);
}
mv.setId(View.generateViewId());
mv.setDrawingCacheEnabled(false);
mv.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.MATCH_PARENT));
drawerBox.addView(mv);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(Color.BLACK);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(3);
mv.setDrawingCacheEnabled(true);
}
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