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 ： https://download.csdn.net/download/u012539700/10289194
