[Android实例] 手写签名，画笔颜色选择器

该篇文章从eoeAndroid搬迁过来的，原文地址：[Android实例] 手写签名，画笔颜色选择器

今天没事做，突然想做一下手写签名的东西，然后就开始行动了，然后做了一天，终于完善了Demo。 在这个手写签名demo中，有以下功能：

1.选择画笔的颜色

2.使用橡皮擦

3.清除或重头开始绘制图片

4.上一步或下一步绘制的效果

5.得到当前展示的绘制效果

主要代码：

手写绘制板：

@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
if (isFirst) {
cacheBitmap = Bitmap.createBitmap(getWidth(), getHeight(),
Config.ARGB_8888);
cacheCanvas = new Canvas(cacheBitmap);
cacheCanvas.drawColor(Color.WHITE);
addBitmap();
isFirst = false;
}
canvas.drawBitmap(cacheBitmap, 0, 0, null);
canvas.drawPath(path, paint);
}

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
int curW = cacheBitmap != null ? cacheBitmap.getWidth() : 0;
int curH = cacheBitmap != null ? cacheBitmap.getHeight() : 0;
if (curW >= w && curH >= h) {
return;
}
if (curW < w)
curW = w;
if (curH < h)
curH = h;
Bitmap newBitmap = Bitmap.createBitmap(curW, curH,
Bitmap.Config.ARGB_8888);
Canvas newCanvas = new Canvas();
newCanvas.setBitmap(newBitmap);
if (cacheBitmap != null) {
newCanvas.drawBitmap(cacheBitmap, 0, 0, null);
}
cacheBitmap = newBitmap;
cacheCanvas = newCanvas;
}

@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getActionMasked()) {
case MotionEvent.ACTION_DOWN:
Log.i("Log", "ACTION_DOWN");
isClear = false;
currentX = event.getX(event.getActionIndex());
currentY = event.getY(event.getActionIndex());
path.moveTo(currentX, currentY);
break;
case MotionEvent.ACTION_MOVE:
if (isOtherTouch) {
return true;
}
float x = event.getX(event.getActionIndex());
float y = event.getY(event.getActionIndex());
path.quadTo(currentX, currentY, x, y);
currentX = x;
currentY = y;
break;
case MotionEvent.ACTION_UP:
isOtherTouch = false;
cacheCanvas.drawPath(path, paint);
path.reset();
while (position + 1 < bitmapList.size()) {
bitmapList.remove(bitmapList.size() - 1);
}
addBitmap();
break;
case MotionEvent.ACTION_POINTER_DOWN:
isOtherTouch = true;
break;
case MotionEvent.ACTION_POINTER_UP:
break;

}
invalidate();
return true;
}

颜色选择器：参照这位童鞋的代码http://www.linuxidc.com/Linux/2012-01/51167.htm



下载地址：项目代码