这篇文章主要为大家详细介绍了wpf中自定义gridlengthanimation的相关资料，具有一定的参考价值，感兴趣的小伙伴们可以参考一下
需求
我们想在编辑一个列表中某一个条目时，将编辑的详情内容也放置当前面，比如右侧。
可以通过将一个grid,分成两个cloumn,动态调整两个cloumn的width，就可以实现这个需求。
我们知道，clomun的width是个，而默认的动画没有这样子的。我们就需要自己实现这样一人动画。
设计
我们从animation的类图上看到
我们可以从需求
我们想在编辑一个列表中某一个条目时，将编辑的详情内容也放置当前面，比如右侧。
可以通过将一个grid,分成两个cloumn,动态调整两个cloumn的width，就可以实现这个需求。
我们知道，clomun的width是个gridlength，而默认的动画没有这样子的。我们就需要自己实现这样一人动画。
设计
我们从animation的类图上看到animationtimeline继承，重写其getcurrentvalue
public class gridlengthanimation : animationtimeline
{
/// <summary>
/// returns the type of object to animate
/// </summary>
public override type targetpropertytype => typeof(gridlength);
/// <summary>
/// creates an instance of the animation object
/// </summary>
/// <returns>returns the instance of the gridlengthanimation</returns>
protected override system.windows.freezable createinstancecore()
{
return new gridlengthanimation();
}
/// <summary>
/// dependency property for the from property
/// </summary>
public static readonly dependencyproperty fromproperty = dependencyproperty.register("from", typeof(gridlength),
typeof(gridlengthanimation));
/// <summary>
/// clr wrapper for the from depenendency property
/// </summary>
public gridlength from
{
get
{
return (gridlength)getvalue(gridlengthanimation.fromproperty);
}
set
{
setvalue(gridlengthanimation.fromproperty, value);
}
}
/// <summary>
/// dependency property for the to property
/// </summary>
public static readonly dependencyproperty toproperty = dependencyproperty.register("to", typeof(gridlength),
typeof(gridlengthanimation));
/// <summary>
/// clr wrapper for the to property
/// </summary>
public gridlength to
{
get
{
return (gridlength)getvalue(gridlengthanimation.toproperty);
}
set
{
setvalue(gridlengthanimation.toproperty, value);
}
}
/// <summary>
/// animates the grid let set
/// </summary>
/// <param name="defaultoriginvalue">the original value to animate</param>
/// <param name="defaultdestinationvalue">the final value</param>
/// <param name="animationclock">the animation clock (timer)</param>
/// <returns>returns the new grid length to set</returns>
public override object getcurrentvalue(object defaultoriginvalue,
object defaultdestinationvalue, animationclock animationclock)
{
double fromval = ((gridlength)getvalue(gridlengthanimation.fromproperty)).value;
double toval = ((gridlength)getvalue(gridlengthanimation.toproperty)).value;
if (fromval > toval)
return new gridlength((1 - animationclock.currentprogress.value) * (fromval - toval) + toval, gridunittype.star);
else
return new gridlength(animationclock.currentprogress.value * (toval - fromval) + fromval, gridunittype.star);
}
如上所示，我们仿着默认动画实现了from,to,同时将其属性定义为gridlength,当动画执行时，我们重写了getcurrentvalue,使其根据from/to属性相关联。
优化
通过以上代码，我们实现了在gridlength变化时，实现动画。但是，试用后我们发现，动画，有点太线性。这个时候，怎么办？
可以通过引入easingfunction来实现。我们知道easingfunction其实就是一个与时间t有关的时间函数f(t).通过时间函数的处理，我们使动画过渡不要那么线性。
/// <summary>
/// the <see cref="easingfunction" /> dependency property's name.
/// </summary>
public const string easingfunctionpropertyname = "easingfunction";
/// <summary>
/// gets or sets the value of the <see cref="easingfunction" />
/// property. this is a dependency property.
/// </summary>
public ieasingfunction easingfunction
{
get
{
return (ieasingfunction)getvalue(easingfunctionproperty);
}
set
{
setvalue(easingfunctionproperty, value);
}
}
/// <summary>
/// identifies the <see cref="easingfunction" /> dependency property.
/// </summary>
public static readonly dependencyproperty easingfunctionproperty = dependencyproperty.register(
easingfunctionpropertyname,
typeof(ieasingfunction),
typeof(gridlengthanimation),
new uipropertymetadata(null));
对应的，还要重写getcurrentvalue函数。
public override object getcurrentvalue(object defaultoriginvalue,
object defaultdestinationvalue, animationclock animationclock)
{
double fromval = ((gridlength)getvalue(fromproperty)).value;
double toval = ((gridlength)getvalue(toproperty)).value;
//check that from was set from the caller
//if (fromval == 1)
// //set the from as the actual value
// fromval = ((gridlength)defaultdestinationvalue).value;
double progress = animationclock.currentprogress.value;
ieasingfunction easingfunction = easingfunction;
if (easingfunction != null)
{
progress = easingfunction.ease(progress);
}
if (fromval > toval)
return new gridlength((1 - progress) * (fromval - toval) + toval, gridunittype.star);
return new gridlength(progress * (toval - fromval) + fromval, gridunittype.star);
}
使用
<anim:gridlengthanimation storyboard.targetproperty="width" from="0" to="*" duration="0:0:0.5"/>
【相关推荐】
1. asp.net免费视频教程
2. c# winform中实现快捷键自定义设置实例，_php教程
3. 分享微信公众号开发自定义菜单实例教程
以上就是wpf中自定义gridlengthanimation的实例教程的详细内容。