在我的 android 应用程序中，用户在我的应用程序的表单中进行签名。签名必须是编辑、清除、保存。我确实保存并清除。但编辑不起作用我使用了下面的代码
mContent = (LinearLayout) findViewById(R.id.linearLayout);
mSignature = new signature(this, null);
mSignature.setBackgroundColor(Color.WHITE);
mContent.addView(mSignature, LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
mClear = (Button)findViewById(R.id.clear);
mGetSign = (Button)findViewById(R.id.getsign);
mGetSign.setEnabled(false);
mCancel = (Button)findViewById(R.id.cancel);
mView = mContent;
mClear.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
Log.v("log_tag", "Panel Cleared");
mSignature.clear();
mGetSign.setEnabled(false);
}
});
mGetSign.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
Log.v("log_tag", "Panel Saved");
mView.setDrawingCacheEnabled(true);
mSignature.save(mView);
Bundle b = new Bundle();
b.putString("status", "done");
b.putParcelable("data", mBitmap);
Intent intent = new Intent();
intent.putExtras(b);
setResult(RESULT_OK,intent);
finish();
}
});
mCancel.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
Log.v("log_tag", "Panel Canceled");
Bundle b = new Bundle();
b.putString("status", "cancel");
Intent intent = new Intent();
intent.putExtras(b);
setResult(RESULT_OK,intent);
finish();
}
});
}
@Override
protected void onDestroy() {
Log.w("GetSignature", "onDestory");
super.onDestroy();
}
public class signature extends View
{
private static final float STROKE_WIDTH = 5f;
private static final float HALF_STROKE_WIDTH = STROKE_WIDTH / 2;
private Paint paint = new Paint();
private Path path = new Path();
private float lastTouchX;
private float lastTouchY;
private final RectF dirtyRect = new RectF();
public signature(Context context, AttributeSet attrs)
{
super(context, attrs);
paint.setAntiAlias(true);
paint.setColor(Color.BLACK);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeWidth(STROKE_WIDTH);
}
public void save(View v)
{
Log.v("log_tag", "Width: " + v.getWidth());
Log.v("log_tag", "Height: " + v.getHeight());
if(mBitmap == null)
{
mBitmap = Bitmap.createBitmap (mContent.getWidth(), mContent.getHeight(), Bitmap.Config.RGB_565);;
}
Canvas canvas = new Canvas(mBitmap);
try
{
FileOutputStream mFileOutStream = new FileOutputStream(mypath);
v.draw(canvas);
mBitmap.compress(Bitmap.CompressFormat.PNG, 90, mFileOutStream);
mFileOutStream.flush();
mFileOutStream.close();
// String url = Images.Media.insertImage(getContentResolver(), mBitmap, "title", null);
// Log.v("log_tag","url: " + url);
//In case you want to delete the file
//boolean deleted = mypath.delete();
//Log.v("log_tag","deleted: " + mypath.toString() + deleted);
//If you want to convert the image to string use base64 converter
}
catch(Exception e)
{
Log.v("log_tag", e.toString());
}
}
public void clear()
{
path.reset();
invalidate();
}
@Override
protected void onDraw(Canvas canvas)
{
canvas.drawPath(path, paint);
}
@Override
public boolean onTouchEvent(MotionEvent event)
{
float eventX = event.getX();
float eventY = event.getY();
mGetSign.setEnabled(true);
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN:
path.moveTo(eventX, eventY);
lastTouchX = eventX;
lastTouchY = eventY;
return true;
case MotionEvent.ACTION_MOVE:
case MotionEvent.ACTION_UP:
resetDirtyRect(eventX, eventY);
int historySize = event.getHistorySize();
for (int i = 0; i < historySize; i++)
{
float historicalX = event.getHistoricalX(i);
float historicalY = event.getHistoricalY(i);
expandDirtyRect(historicalX, historicalY);
path.lineTo(historicalX, historicalY);
}
path.lineTo(eventX, eventY);
break;
default:
debug("Ignored touch event: " + event.toString());
return false;
}
invalidate((int) (dirtyRect.left - HALF_STROKE_WIDTH),
(int) (dirtyRect.top - HALF_STROKE_WIDTH),
(int) (dirtyRect.right + HALF_STROKE_WIDTH),
(int) (dirtyRect.bottom + HALF_STROKE_WIDTH));
lastTouchX = eventX;
lastTouchY = eventY;
return true;
}
private void debug(String string){
}
private void expandDirtyRect(float historicalX, float historicalY)
{
if (historicalX < dirtyRect.left)
{
dirtyRect.left = historicalX;
}
else if (historicalX > dirtyRect.right)
{
dirtyRect.right = historicalX;
}
if (historicalY < dirtyRect.top)
{
dirtyRect.top = historicalY;
}
else if (historicalY > dirtyRect.bottom)
{
dirtyRect.bottom = historicalY;
}
}
private void resetDirtyRect(float eventX, float eventY)
{
dirtyRect.left = Math.min(lastTouchX, eventX);
dirtyRect.right = Math.max(lastTouchX, eventX);
dirtyRect.top = Math.min(lastTouchY, eventY);
dirtyRect.bottom = Math.max(lastTouchY, eventY);
}
}