前段时间产品那边让我做一个动画，要求是先以横线的方式横向展开，在纵向展示图片，最后展示几秒动画在原路返回,随后我在网上查找资料，发现这方面的记录很少，最后自己写了一个
后期还会慢慢改进；
转载请说明出处：http://www.cnblogs.com/hyylog/p/5659619.html
步骤：1、先利用控件的ondraw()方法，结合数字上升的动画，实现划线的步骤；
2、利用postInvalidate()方法，调用dispatchDraw（）方法来展示图片的展现
具体代码如下：
public class ExpandView extends LinearLayout {
private Bitmap mBitmap;
private int linearDuration = 500;
private int expandDuration = 800;
private int dismissDuration = 1500;
private Paint mpPaint;
private Paint bitPaint;
private int resultLinear = 40; // 划线动画执行距离完成启动下一个动画的距离 （为防止动画启动延迟产生的卡顿）
private int resultBitMap = 30; // 画图动画距离启动下次动画的距离 （为防止动画启动延迟产生的卡顿）
private int type = 1; // 1 为展开动画 2 为回缩动画
private ValueAnimator valueAnimator = null;
private ValueAnimator valueAnimator2 = null;
private int radus = 8;
private int velua = 0;
private int veluaLinear = 0;
private View view;
private boolean isStart = false; // 保证动画只启动一次
private Handler handler = new Handler() {
public void handleMessage(android.os.Message msg) {
switch (msg.what) {
case 0:
velua = 0;
invalidate();
break;
case 1:
start(2);
break;
default:
break;
}
};
};
public ExpandView(Context context, AttributeSet attrs) {
super(context, attrs);
inite();
}
public void setView(View view) {
this.view = view;
}
public ExpandView(Context context) {
super(context);
inite();
}
public void inite() {
bitPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mpPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mpPaint.setStrokeWidth(5);
mpPaint.setColor(Color.BLACK);
}
public void setRadus(int radus) {
this.radus = radus;
}
public void setDistance(int linear, int bit) {
resultBitMap = bit;
resultLinear = linear;
}
public void setDuration(int linearDuration, int expandDuration,
int dismissDuration) {
this.linearDuration = linearDuration;
this.expandDuration = expandDuration;
this.dismissDuration = dismissDuration;
}
public void setLinearPaintColor(int color) {
mpPaint.setColor(color);
}
public void start(int type) {
this.type = type;
valueAnimator.cancel();
valueAnimator2.cancel();
handler.removeMessages(1);
handler.sendEmptyMessage(0);
isStart = true;
if (type == 1) {
valueAnimator.start();
} else if (type == 2) {
valueAnimator2.start();
}
}
public void initedAnimation() {
clearAnimations();
mBitmap = getBitmap();
Log.i("", "pppp====veluaLinear=>>"+(mBitmap.getWidth() - radus * 2));
valueAnimator = ValueAnimator.ofInt(0, mBitmap.getWidth() - radus * 2);
valueAnimator2 = ValueAnimator.ofInt(0, mBitmap.getHeight());
valueAnimator.setDuration(linearDuration);
valueAnimator2.setDuration(expandDuration);
valueAnimator.addUpdateListener(new AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
veluaLinear = (Integer) animation.getAnimatedValue();
if (veluaLinear > (mBitmap.getWidth() - resultLinear)&& type == 1) {
if (isStart) {
valueAnimator2.start();
isStart = false;
}
}
postInvalidate();
}
});
valueAnimator2.addUpdateListener(new AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator animation) {
velua = (Integer) animation.getAnimatedValue();
postInvalidate();
veluaLinear = 0;
}
});
}
@Override
protected void dispatchDraw(Canvas canvas) {
super.dispatchDraw(canvas);
if (mBitmap != null) {
Rect src;
Rect des;
if (type == 1) {
canvas.drawLine(mBitmap.getWidth() - radus, 0,mBitmap.getWidth() - radus - veluaLinear, 0,mpPaint);
src = new Rect(0, 0, mBitmap.getWidth(), velua);
des = new Rect(0, 0, mBitmap.getWidth(), velua);
} else {
canvas.drawLine(mBitmap.getWidth() - radus, 0, radus+ veluaLinear, 0, mpPaint);
src = new Rect(0, 0, mBitmap.getWidth(), mBitmap.getHeight()- velua);
des = new Rect(0, 0, mBitmap.getWidth(), mBitmap.getHeight()- velua);
}
canvas.drawBitmap(mBitmap, src, des, bitPaint);
if (velua == mBitmap.getHeight() && type == 1) {
handler.removeMessages(1);
handler.sendEmptyMessageDelayed(1, dismissDuration);
}
if (type == 2 && velua >= mBitmap.getHeight() - resultBitMap) {
if (isStart) {
valueAnimator.start();
isStart = false;
}
}
}
}
public void clearAnimations() {
if (valueAnimator != null)
valueAnimator.cancel();
if (valueAnimator2 != null)
valueAnimator.cancel();
handler.removeMessages(1);
veluaLinear=0;
handler.sendEmptyMessage(0);
if (mBitmap != null && !mBitmap.isRecycled()) {
mBitmap.recycle();
}
}
private Bitmap getBitmap() {
// 打开图像缓存
view.setDrawingCacheEnabled(true);
// 必须调用measure和layout方法才能成功保存可视组件的截图到png图像文件
// 测量View大小
view.measure(MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED),
MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
// 发送位置和尺寸到View及其所有的子View
view.layout(0, 0, view.getMeasuredWidth(), view.getMeasuredHeight());
Bitmap bitmap = view.getDrawingCache();
android.widget.FrameLayout.LayoutParams params = (android.widget.FrameLayout.LayoutParams) getLayoutParams();
params.width=bitmap.getWidth();
params.height=bitmap.getHeight();
setLayoutParams(params);
return bitmap;
}
}