时钟动图效果如下：
画图逻辑如下：
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
float hScale = 1.0f;
float vScale = 1.0f;
if (widthMode != MeasureSpec.UNSPECIFIED && widthSize < mDialWidth)
{
hScale = (float) widthSize / (float) mDialWidth;
}
if (heightMode != MeasureSpec.UNSPECIFIED && heightSize < mDialHeight)
{
vScale = (float) heightSize / (float) mDialHeight;
}
float scale = Math.min(hScale, vScale);
setMeasuredDimension(resolveSize((int) (mDialWidth * scale), widthMeasureSpec), resolveSize((int) (mDialHeight * scale), heightMeasureSpec));
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh)
{
super.onSizeChanged(w, h, oldw, oldh);
mChanged = true;
}
@Override
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
boolean changed = mChanged;
if (changed)
{
mChanged = false;
}
int availableWidth = getWidth();
int availableHeight = getHeight();
int x = availableWidth / 2;
int y = availableHeight / 2;
final Drawable dial = mDial;
int w = dial.getIntrinsicWidth();
int h = dial.getIntrinsicHeight();
boolean scaled = false;
if (availableWidth < w || availableHeight < h)
{
scaled = true;
float scale = Math.min((float) availableWidth / (float) w, (float) availableHeight / (float) h);
canvas.save();
canvas.scale(scale, scale, x, y);
}
if (changed)
{
dial.setBounds(x - (w / 2), y - (h / 2), x + (w / 2), y + (h / 2));
}
dial.draw(canvas);
canvas.save();
canvas.rotate(mHour / 12.0f * 360.0f, x, y);
final Drawable hourHand = mHourHand;
if (changed)
{
w = hourHand.getIntrinsicWidth();
h = hourHand.getIntrinsicHeight();
hourHand.setBounds(x - (w / 2), y - (h / 2), x + (w / 2), y + (h / 2));
}
hourHand.draw(canvas);
canvas.restore();
canvas.save();
canvas.rotate(mMinutes / 60.0f * 360.0f, x, y);
final Drawable minuteHand = mMinuteHand;
if (changed)
{
w = minuteHand.getIntrinsicWidth();
h = minuteHand.getIntrinsicHeight();
minuteHand.setBounds(x - (w / 2), y - (h / 2), x + (w / 2), y + (h / 2));
}
minuteHand.draw(canvas);
canvas.restore();
//add second draw
canvas.save();
canvas.rotate(mSeconds / 60.0f * 360.0f, x, y);
final Drawable secondHand = mSecondHand;
if (changed)
{
w = secondHand.getIntrinsicWidth();
h = secondHand.getIntrinsicHeight();
secondHand.setBounds(x - (w / 2), y - (h / 2), x + (w / 2), y + (h / 2));
}
secondHand.draw(canvas);
canvas.restore();
if (scaled)
{
canvas.restore();
}
}
完整图片以及代码下载地址 ： /download/u012539700/10289194
