这是我可以在视图上绘制的代码，但是当我为视图设置背景时，我无法在背景图像上绘制，请帮帮我。提前致谢
public class FingerPaint extends GraphicsActivity
implements MyColorPickerDialog.OnColorChangedListener {
ListView dialog_ListView;
String[] listContent = {
"Stroke Size 1", "Stroke Size 2", "Stroke Size 3", "Stroke Size 4",
"Stroke Size 5","Stroke Size 10","Stroke Size 20","Stroke Size 30"
};
String[] effectContent = {
"Normal", "Blur", "Emboss", "SrcATop" };
private static int FONT_SIZE=5;
private static int COLOR_CODE=Color.BLACK;
public int mPos;
private Bitmap mBitmap;
MyView mv;
ImageShowActivity imageShowActivity =new ImageShowActivity();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mv= new MyView(this);
mv.setDrawingCacheEnabled(true);
//mv.setBackgroundResource(R.drawable.image1_layer1);
setContentView(mv);
initialiazation();
mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 },
0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);// TODO Auto-generated method stub
loadImageToEddit();
}
private void initialiazation() {
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(COLOR_CODE);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(FONT_SIZE);
}
private void loadImageToEddit() {
Bundle bundle=getIntent().getExtras();
if(bundle!=null){
int pos=bundle.getInt("image_path");
if(pos!=0){
// Bitmap bitmap =BitmapFactory.decodeFile(ImageShowActivity.imagePathList.get(path));
// mv=new MyView(this,bitmap);
//Drawable d = new BitmapDrawable(getResources(),bitmap);
//mv.setBackground(d);
mPos=pos;
}
}
}
private Paint mPaint;
private MaskFilter mEmboss;
private MaskFilter mBlur;
public void colorChanged(int color) {
mPaint.setColor(color);
COLOR_CODE=color;
}
private void fontChanged(Float size){
mPaint.setStrokeWidth(size);
}
private void showEffectDialog(){
final Dialog dialog = new Dialog(FingerPaint.this);
dialog.setContentView(R.layout.font_dialog);
dialog.setCancelable(true);
dialog.setTitle("Font");
WindowManager.LayoutParams params = new WindowManager.LayoutParams();
params.width=200; params.height=250;
params.gravity = Gravity.CENTER_HORIZONTAL;
dialog.getWindow().setAttributes(params);
ArrayAdapter<String> ad =new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,effectContent);
ListView list = (ListView) dialog.findViewById(R.id.dialoglist);
list.setAdapter(ad);
dialog.show();
list.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int pos,
long arg3) {
switch (pos) {
case 0:
mPaint.setMaskFilter(null);
initialiazation();
break;
case 1:
mPaint.setMaskFilter(null);
//initialiazation();
mPaint.setStrokeWidth(FONT_SIZE);
if (mPaint.getMaskFilter() != mBlur) {
mPaint.setMaskFilter(mBlur);
} else {
mPaint.setMaskFilter(null);
}
break;
case 2:
mPaint.setMaskFilter(null);
if (mPaint.getMaskFilter() != mEmboss) {
mPaint.setMaskFilter(mEmboss);
} else {
mPaint.setMaskFilter(null);
}
break;
case 3:
mPaint.setMaskFilter(null);
mPaint.setXfermode(new PorterDuffXfermode(
PorterDuff.Mode.SRC_ATOP));
mPaint.setAlpha(0x80);
break;
default:
break;
}
dialog.dismiss();
}
});
}
private void showDialog(){
final Dialog dialog = new Dialog(FingerPaint.this);
dialog.setContentView(R.layout.font_dialog);
dialog.setCancelable(true);
dialog.setTitle("Font");
WindowManager.LayoutParams params = new WindowManager.LayoutParams();
params.width=200; params.height=250;
params.gravity = Gravity.CENTER_HORIZONTAL;
dialog.getWindow().setAttributes(params);
ArrayAdapter<String> ad =new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,listContent);
ListView list = (ListView) dialog.findViewById(R.id.dialoglist);
list.setAdapter(ad);
dialog.show();
list.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int pos,
long arg3) {
switch (pos) {
case 0:
FONT_SIZE=1;
fontChanged(1f);
break;
case 1:
FONT_SIZE=2;
fontChanged(2f);
break;
case 2:
FONT_SIZE=3;
fontChanged(3f);
break;
case 3:
FONT_SIZE=4;
fontChanged(4f);
break;
case 4:
FONT_SIZE=5;
fontChanged(5f);
break;
case 5:
FONT_SIZE=10;
fontChanged(10f);
break;
case 6:
FONT_SIZE=20;
fontChanged(20f);
break;
case 7:
FONT_SIZE=30;
fontChanged(30f);
break;
default:
break;
}
dialog.dismiss();
}
});
}
public class MyView extends View {
private static final float MINP = 0.25f;
private static final float MAXP = 0.75f;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
public MyView(Context c) {
super(c);
// DisplayMetrics dm = new DisplayMetrics();
// getWindowManager().getDefaultDisplay().getMetrics(dm);
// int w = dm.widthPixels;
// int h=dm.heightPixels;
// mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
// mBitmap.eraseColor(c)
// mCanvas = new Canvas(mBitmap);
// mCanvas.drawColor(0xFFAAAAAA);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
// mPaint.setStrokeWidth(FONT_SIZE);
}
@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.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.WHITE);
if(mPos!=0){
Bitmap bitmap =BitmapFactory.decodeFile(ImageShowActivity.imagePathList.get(mPos));
mBitmap=bitmap;
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
//canvas.drawPath(mPath, mPaint);
Log.d("onDraw", "if called");
//invalidate();
}else{
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
Log.d("onDraw", "else called");
}
canvas.drawPath(mPath, mPaint);
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPath.reset();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
}
return true;
}
}
private static final int COLOR_MENU_ID = Menu.FIRST;
private static final int FONT_ID = Menu.FIRST + 1;
private static final int BLUR_MENU_ID = Menu.FIRST + 2;
private static final int ERASE_MENU_ID = Menu.FIRST + 3;
private static final int SRCATOP_MENU_ID = Menu.FIRST + 4;
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
menu.add(0, COLOR_MENU_ID, 0, "Color").setShortcut('3', 'c');
menu.add(0, FONT_ID, 0, "Font Size").setShortcut('4', 's');
menu.add(0, BLUR_MENU_ID, 0, "Effects").setShortcut('5', 'z');
menu.add(0, ERASE_MENU_ID, 0, "Erase").setShortcut('5', 'z');
menu.add(0, SRCATOP_MENU_ID, 0, "Save").setShortcut('5', 'z');
/**** Is this the mechanism to extend with filter effects?
Intent intent = new Intent(null, getIntent().getData());
intent.addCategory(Intent.CATEGORY_ALTERNATIVE);
menu.addIntentOptions(
Menu.ALTERNATIVE, 0,
new ComponentName(this, NotesList.class),
null, intent, 0, null);
*****/
return true;
}
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
super.onPrepareOptionsMenu(menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
mPaint.setXfermode(null);
mPaint.setAlpha(0xFF);
switch (item.getItemId()) {
case COLOR_MENU_ID:
// initialiazation();
new MyColorPickerDialog(this,this, Color.RED, false).show();
return true;
case FONT_ID:
showDialog();
//emboss
//
return true;
case BLUR_MENU_ID:
showEffectDialog();
//
return true;
case ERASE_MENU_ID:
//initialiazation();
mPaint.setAlpha(0xFF);//transperent color
mPaint.setMaskFilter(null);
mPaint.setXfermode(new PorterDuffXfermode(
PorterDuff.Mode.CLEAR));
return true;
case SRCATOP_MENU_ID:
// mPaint.setXfermode(new PorterDuffXfermode(
// PorterDuff.Mode.SRC_ATOP));
// mPaint.setAlpha(0x80);
saveImageDialog2();
return true;
}
return super.onOptionsItemSelected(item);
}
//src fingerpaint.java
private void saveImageDialog2() {
AlertDialog.Builder editalert = new AlertDialog.Builder(FingerPaint.this);
editalert.setTitle("Please Enter the name with which you want to Save");
final EditText input = new EditText(FingerPaint.this);
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT);
input.setLayoutParams(lp);
editalert.setView(input);
editalert.setPositiveButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
String name= input.getText().toString();
Bitmap bitmap = mv.getDrawingCache();
File directory= new File(Environment.getExternalStorageDirectory(),"Hand Brush/");
File myPath=new File(directory,name);
File file = new File(myPath+".png");
try
{
if(!file.exists())
{
file.createNewFile();
}
FileOutputStream ostream = new FileOutputStream(file);
bitmap.compress(CompressFormat.PNG, 10, ostream);
//System.out.println("saving......................................................"+path);
ostream.close();
mv.invalidate();
}
catch (Exception e)
{
e.printStackTrace();
}finally
{
mv.setDrawingCacheEnabled(false);
}
}
});
editalert.show();
}
}
