【转】android奇效之可伸缩View带互相挤压效果-初级篇

2013-10-31

【转】android特效之可伸缩View带互相挤压效果--初级篇?转自：http://blog.csdn.net/manymore13/article/deta

【转】android特效之可伸缩View带互相挤压效果--初级篇

转自：http://blog.csdn.net/manymore13/article/details/12799061

本次我要向大家介绍一个Android特效，这个特效也是我在某款软件中看到的，至于软件叫什么，我今天就不说

它的名字。我就不免费为它做广告了。【转】android奇效之可伸缩View带互相挤压效果-初级篇

好了，我来上一张动态效果图在下面，屏幕小的请往下拉。

我不知道原软件是怎么个实现法，在这里我只是说说我的实现方法，代码可能不太好，这只是本人的一个idea 原理很简单！

? ? ??特效实现原理：

改变按钮的宽度，每次当你点击按钮时，只有两个按钮改变宽度，一个变长，一个变短，只是这个变化是慢慢

进行，不是秒变的，你懂的，这就是动画效果。你点击短的按钮后会渐渐地变长，长的按钮会随着被压缩，其他按钮宽度不变。

我写这篇文章想起到一个抛砖引玉的效果，希望读者看了这篇文章后继续写个更好的文章。当然你不要忘记我啊，

记得要与我和大家分享。

?下面是本次Demo运行后的效果图：

【转】android奇效之可伸缩View带互相挤压效果-初级篇

可以看到view被挤压的效果，点击短的view会慢慢长大。在短的view慢慢长大的同时，最长的view会慢慢缩小，而且每次动画结束后都

有一个最长的view 。我这里所说的view在本次Demo中是按钮，当然你也可以换成其他的控件，或者是ViewGroup的子类也行。

[java]

public?class?PinchActivity?extends?Activity?implements?View.OnClickListener?{??

????private?final?static?String?TAG?=?"MainActivity";??

??????

????//?屏幕宽度??

????private?int?screentWidth?=?0;??

??????

????//?View可伸展最长的宽度??

????private?int?maxWidth;??

??????

????//?View可伸展最小宽度??

????private?int?minWidth;??

??????

????//?当前点击的View??

????private?View?currentView;??

??????

????//?显示最长的那个View??

????private?View?preView;??

??????

????//?主布局ViewGroup??

????private?LinearLayout?mainContain;??

??????

????//?标识符?动画是否结束??

????private?boolean?animationIsEnd?=?true;??

??????

????//?变大操作??

????private?static?final?int?OPE_BIG?=?1;??

??????

????//?变小操作??

????private?static?final?int?OPE_SMALL?=?2;??

??????

????//?当前操作?-1表示无效操作??

????private?int?currentOpe?=?-1;??

??????

????//?前进的步伐距离??

????private?static?final?int?STEP?=?10;??

????@Override??

????protected?void?onCreate(Bundle?savedInstanceState)???

????{??

????????super.onCreate(savedInstanceState);??

??????????

????????setContentView(R.layout.activity_main);??

????????initCommonData();??

??????????

????????initViewData();??

??????????

????????measureWidth(screentWidth);???

????}??

????private?void?initViewData()?{??

????????mainContain?=?(LinearLayout)?this.findViewById(R.id.main_contain);??

????????View?child;??

????????int?childCount?=?mainContain.getChildCount();??

????????for?(int?i?=?0;?i?<?childCount;?i++)?{??

????????????child?=?mainContain.getChildAt(i);??

????????????child.setOnClickListener(this);??

????????}??

????}??

??????

????private?void?initCommonData()??

????{??

????????DisplayMetrics?metric?=?new?DisplayMetrics();??

????????getWindowManager().getDefaultDisplay().getMetrics(metric);??

????????screentWidth?=?metric.widthPixels;?//?屏幕宽度（像素）??

????}??

????private?void?setCurrentViewParams()?{??

????????if?(currentView?==?null)?{??

????????????return;??

????????}??

????????LayoutParams?params?=?currentView.getLayoutParams();??

????????if?(params?==?null)?{??

????????????return;??

????????}??

????????int?realWidth?=?params.width;??

????????int?nextWidth?=?0;??

????????if?(currentOpe?==?OPE_BIG)?{??

????????????nextWidth?=?realWidth?+?STEP;??

????????}?else?if?(currentOpe?==?OPE_SMALL)?{??

????????????nextWidth?=?realWidth?-?STEP;??

????????}??

????????if?(nextWidth?>?maxWidth)?{??

????????????nextWidth?=?maxWidth;??

????????}?else?if?(nextWidth?<?minWidth)?{??

????????????nextWidth?=?minWidth;??

????????}??

????????params.width?=?nextWidth;??

????????currentView.setLayoutParams(params);??

????????if?(nextWidth?==?maxWidth?||?nextWidth?==?minWidth)?{??

????????????animationIsEnd?=?true;??

????????????onOffClickable();??

????????????stopAnimation();??

????????????return;??

????????}??

????????mHandler.sendEmptyMessageDelayed(1,?20);??

????}??

????//?初始化宽度?测量max?min?长度??

????private?void?measureWidth(int?screenWidth)?{??

??????????

????????int?halfWidth?=?screenWidth?/?2;??

????????maxWidth?=?halfWidth?-?50;??

????????minWidth?=?(screenWidth?-?maxWidth)?/?(mainContain.getChildCount()?-?1);??

????????View?child;??

????????int?childCount?=?mainContain.getChildCount();??

????????for?(int?i?=?0;?i?<?childCount;?i++)?{??

????????????child?=?mainContain.getChildAt(i);??

????????????LayoutParams?params?=?child.getLayoutParams();??

????????????if?(i?==?0)?{??

????????????????preView?=?child;??

????????????????params.width?=?maxWidth;??

????????????}?else?{??

????????????????params.width?=?minWidth;??

????????????}??

????????????child.setLayoutParams(params);??

????????}??

????}??

????//?这里用handler更新界面??

????private?Handler?mHandler?=?new?Handler()?{??

????????@Override??

????????public?void?handleMessage(Message?msg)?{??

????????????if?(msg.what?==?1)?{??

????????????????setCurrentViewParams();??

????????????}???

????????}??

????};??

????//?停止动画??

????private?void?stopAnimation()?{??

????????currentOpe?=?-1;??

????????currentView?=?null;??

????}??

????private?void?startAnimation()?{??

????????if?(currentView?==?null?||?currentOpe?==?-1)?{??

????????????Log.d(TAG,?"无效动画");??

????????????return;??

????????}??

??????????

????????animationIsEnd?=?false;??

????????onOffClickable();??

????????mHandler.sendEmptyMessage(1);??

????}??

????@Override??

????public?void?onClick(View?v)?{??

??????????

????????int?id?=?v.getId();??

??????????

????????switch?(id)?{??

??????????

????????case?R.id.btnOne:??

????????????currentView?=?mainContain.getChildAt(0);??

????????????break;??

????????case?R.id.btnTwo:??

????????????currentView?=?mainContain.getChildAt(1);??

????????????break;??

????????case?R.id.btnThree:??

????????????currentView?=?mainContain.getChildAt(2);??

????????????break;??

????????case?R.id.btnFour:??

????????????currentView?=?mainContain.getChildAt(3);??

????????????break;??

????????}??

????????Log.i(TAG,?((Button)?currentView).getText().toString()?+?"?click");??

??????????

????????if?(currentView?!=?null?&&?animationIsEnd)?{??

??????????????

????????????int?currentViewWidth?=?currentView.getWidth();??

??????????????

????????????if?(currentViewWidth?==?maxWidth)?{??

????????????????currentOpe?=?OPE_SMALL;??

????????????}?else?{??

????????????????currentOpe?=?OPE_BIG;??

????????????}??

??????????????

????????????clickEvent(currentView);??

??????????????

????????????startAnimation();??

????????}??

????}??

????private?void?clickEvent(View?view)?{??

????????View?child;??

????????int?childCount?=?mainContain.getChildCount();??

????????for?(int?i?=?0;?i?<?childCount;?i++)?{??

????????????child?=?mainContain.getChildAt(i);??

????????????if?(preView?==?child)?{??

????????????????LinearLayout.LayoutParams?params?=?(android.widget.LinearLayout.LayoutParams)?child??

????????????????????????.getLayoutParams();??

????????????????params.weight?=?1.0f;??

????????????????child.setLayoutParams(params);??

????????????}?else?{??

????????????????LinearLayout.LayoutParams?params?=?(android.widget.LinearLayout.LayoutParams)?child??

????????????????????????.getLayoutParams();??

????????????????params.weight?=?0.0f;??

????????????????params.width?=?minWidth;??

????????????????child.setLayoutParams(params);??

????????????}??

????????}??

????????preView?=?view;??

????????printWeight();??

????}??

????private?void?printWeight()?{??

????????View?child;??

????????int?childCount?=?mainContain.getChildCount();??

????????for?(int?i?=?0;?i?<?childCount;?i++)?{??

????????????child?=?mainContain.getChildAt(i);??

????????????LinearLayout.LayoutParams?params?=?(android.widget.LinearLayout.LayoutParams)?child??

????????????????????.getLayoutParams();??

????????????Log.i("mm1",?((Button)?child).getText()?+?":?"?+?params.weight);??

????????}??

????}??

??????

????//???

????private?void?onOffClickable()??

????{??

????????View?child;??

????????boolean?clickable?=?animationIsEnd;??

????????int?childCount?=?mainContain.getChildCount();??

????????for?(int?i?=?0;?i?<?childCount;?i++)?{??

????????????child?=?mainContain.getChildAt(i);??

????????????child.setClickable(clickable);??

????????}??

????}??

}??

改变控件的宽度或者高度：

?1.获取参数类 ?LayoutParams params =??View.getLayoutParams() ?

?2.[java]

LinearLayout.LayoutParams?params?=?(android.widget.LinearLayout.LayoutParams)?child.getLayoutParams();??

child是一个Button ，在XML中它的父控件是LinearLayout，所以我这里有上面的强转，?LinearLayout.LayoutParams 不仅有设置控件宽度和高度的属性，还有一个本次Demo重点用到的一个属性android:layout_weight?，想必大家在开发中用到这个属性的不在少数吧！

android:layout_weight

Indicates how much of the extra space in the LinearLayout will be allocated to the view associated with these LayoutParams. Specify 0 if the view should not be stretched. Otherwise the extra pixels will be pro-rated among all views whose weight is greater than 0.

大概意思是View根据比例享用多余空间。这个比例就是你设置的这个值的大小，如果你设置它的值为0的话，就等于你没设置这个值，不等于零的话，就按你设的比例来瓜分LinearLayout中的多余空间。具体用法有不懂的请去seach。

最后说一些本次Demo中主要有以下三点不足：

1. 特效动画死板，变化速度死板；

2. 特效动画不能设置动画时间，如遇到高分辨率的机型，动画时间会变长。

3. view只能水平伸缩，不能竖直伸缩。

以上三点不足将在下篇为大家解决。

好了，上述就是本次特效讲解的全部内容，有什么地方说的有误的，欢迎您指正！欢迎拍砖！欢迎留言，如对你有帮助，请不要吝惜你手中的鼠标左键，点赞一个！【转】android奇效之可伸缩View带互相挤压效果-初级篇

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