问题描述

在Bitmap或者OVERLAYING按钮上如何动态的创建一个按钮

我想在视图的 BITMAP或者OVERLAYING按钮上面创建一个按钮。我创建了一个数字签名，签名后，我需要点击一个按钮来保存。我使用的如下代码

public class FingerPaint extends GraphicsActivity   implements OnClickListener {  private TextView pauseButton;protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(new MyView(this));    Capture_SignatureActivity.writeLog(""In FingerPaint class"");    mPaint = new Paint();    mPaint.setAntiAlias(true);    mPaint.setDither(true);    mPaint.setColor(0xFF003F87);    mPaint.setStyle(Paint.Style.STROKE);    mPaint.setStrokeJoin(Paint.Join.ROUND);    mPaint.setStrokeCap(Paint.Cap.ROUND);    mPaint.setStrokeWidth(1); } private Paint mPaint;public void colorChanged(int color) {    Capture_SignatureActivity.writeLog(""In color changed"");    mPaint.setColor(color);}public class MyView extends View{    private static final float MINP = 0.25f;    private static final float MAXP = 0.75f;    private Bitmap  mBitmap;    private Canvas  mCanvas;    private Path    mPath;    private Paint   mBitmapPaint;    private Bitmap overlayDefault;    private Bitmap overlay;    private Canvas c2;    private Paint pTouch;    private float X =  -100;    private float Y =  -100;    public MyView(Context c) {        super(c);        Capture_SignatureActivity.writeLog(""In MyVIEW"");        mPath = new Path();        mBitmapPaint = new Paint(Paint.DITHER_FLAG);          mBitmap =      BitmapFactory.decodeResource(getResources()R.drawable.ic_launcher);        overlayDefault = BitmapFactory.decodeResource(getResources()R.drawable.ic_launcher);        overlay = BitmapFactory.decodeResource(getResources()R.drawable.ic_launcher).copy(Config.ARGB_8888 true);          c2 = new Canvas(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));        pTouch.setMaskFilter(startActivity(FingerPaint.this Capture_SignatureActivity.class));    }    @Override    protected void onSizeChanged(int w int h int oldw int oldh) {        super.onSizeChanged(w h oldw oldh);        System.out.println(""w-->""+w+""-->""+""h--""+h+""-->""+""oldw-->""+oldh+""oldw-->""+oldw);        Capture_SignatureActivity.writeLog(""In  onSizeChanged"");        mBitmap = Bitmap.createBitmap(w h Bitmap.Config.ARGB_8888);                    mCanvas = new Canvas(mBitmap);           }    @Override    protected void onDraw(Canvas canvas) {        Capture_SignatureActivity.writeLog(""In onDraw"");        canvas.drawColor(0xFFFFFFFF);               canvas.drawBitmap(mBitmap 0 0 mBitmapPaint);        canvas.drawPath(mPath mPaint);        c2.drawBitmap(overlayDefault 0 0 null); //exclude this line to show all as you draw        c2.drawCircle(X  Y  80 pTouch);        //draw the overlay over the background          canvas.drawBitmap(overlay 0 0 null);    }    private float mX mY;    private static final float TOUCH_TOLERANCE = 4;    private void touch_start(float x float y) {        Capture_SignatureActivity.writeLog(""In  touch_start"");        mPath.reset();        mPath.moveTo(x y);        mX = x;        mY = y;        System.out.println(""---- "" +mX);    }    private void touch_move(float x float y) {        Capture_SignatureActivity.writeLog(""In  touch_Move"");        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() {        Capture_SignatureActivity.writeLog(""In 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) {        Capture_SignatureActivity.writeLog(""In  touch_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;    }    public void onClick(View v) {        //In myView        startActivity(new Intent(FingerPaint.this Capture_SignatureActivity.class));    }}public void onClick(View v) {    //onCreate}@Overridepublic boolean onCreateOptionsMenu(android.view.Menu menu) {    super.onCreateOptionsMenu(menu);    menu.add(0 1 0 Clear Screen"");    menu.add(0 2 0 Exit Screen"");    return true;} @Overridepublic boolean onMenuItemSelected(int featureId MenuItem item){    switch(item.getItemId())     {    case 1:         startActivity(new Intent(this FingerPaint.class));        break;     case 2:         startActivity(new Intent(this Capture_SignatureActivity.class));        break;     }    return super.onMenuItemSelected(featureId item);}}

创建了图像，但是不能开启activity。怎么解决这个问题呢?

解决方案

在BITMAP或者CANVAS上动态的创建按钮的方法：

public class MainAct extends GrapActivity implements OnClickListener {private Button saveButton;private Button clearButton;// onCreate Activityprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);              // content view     signature = new MyView(this);     // Dynamically created button on bitmap & canvas    RelativeLayout myLayout = new RelativeLayout(this);            myLayout.setLayoutParams(new RelativeLayout.LayoutParams(LayoutParams.FILL_PARENT LayoutParams.FILL_PARENT));     // For Save Button    saveButton = new Button(this);     saveButton.setText(""Save"");     saveButton.setOnClickListener(this);     // For Clear Button    clearButton = new Button(this);     clearButton.setText(""Clear"");     clearButton.setOnClickListener(this);     myLayout.addView(signature);     myLayout.addView(saveButton);     myLayout.addView(clearButton);     RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(100 LayoutParams.WRAP_CONTENT);     //Alignments    params.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);     params.addRule(RelativeLayout.ALIGN_PARENT_LEFT);     saveButton.setLayoutParams(params);     //Alignments    RelativeLayout.LayoutParams params2 = new RelativeLayout.LayoutParams(100 LayoutParams.WRAP_CONTENT);     params2.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);     params2.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);     clearButton.setLayoutParams(params2);     saveButton.bringToFront();     clearButton.bringToFront();     this.setContentView(myLayout);     new Thread(new RefreshRunner()).start();     // onclick listner for CLEAR button    clearButton.setOnClickListener(new OnClickListener() {                  public void onClick(View v) {            //Activity for Clearing the Screen            startActivity(new Intent(ThisAct.this ThisAct.class));            finish();        }    }); // onclick listner for SAVE button        saveButton.setOnClickListener(new OnClickListener() {              public void onClick(View v) {                 //capture the image                  try {                                        saveAsJpg(mBitmap);                         startActivity(new Intent(ThisAct.this MainActivity.class));                    finish();                } catch (IOException e) {                                       e.printStackTrace();                }             }          });     } }

解决方案二：
如果你在RelativeLayout同时添加ImageView和Button。它们会重叠在一起。你可以根据需要设置下定位。

<RelativeLayout android:layout_width=""wrap_content""android:layout_height=""match_parent"" ><ImageView android:....android:..../><Button android:....android:..../></RelativeLayout>