很久没有关注DeepEarth的更新进展了，昨晚上CodePlex看发现DeepEarth已经更新到Silverlight 4版本了，并且做了许多的改变，主要包括如下：
Added SL4 branch folders.
Added upgraded SL4 GeoAPI, NetTopologySuite.
Added SL4 Silverlight toolkit library dlls (April 2010).
Upgraded DeepEarth MapControl to Silverlight 4
Upgraded all DeepEarth TileProviders to Silverlight 4
Upgrade DeepEarth MapControl to use Silverlight 4 inbuilt MouseWheel Events
Create new LocationBase class to replace the PointBase class, and uses Latitude & Longitude
Enable Hardware Acceleration for the MapControl
Upgraded the core controls (navigation, coordinates etc) to Silverlight 4 & integrate with map project.
Fixed Styles for controls and C# code to allow Styles/Templates to display correctly at design time in both VS2010 & Blend 4 RC
Remove the dependicy/referance to NetopologySuite Project and include the relevant parts in our code, upgraded to SL4 code.
Provide an example of a separate control that is a separate project interacting with the map = eg, layer control.
Tested everything works in Out of Browser Mode (OOB)
DeepEarth从Silverlight 3升级到了Silverlight 4，在几何框架中并通过新创建的LocationBase类替换了原来在Silverlight版本中的PointBase基类，并使用了经度（Longitude）和纬度(Latitude)替换了旧版本PointBase中使用的X,Y。
/// The Latitude coordinate of the point
/// </summary>
public double Longitude
{
get { return Point.X; }
set
{
_Point.X = value;
Point = _Point;
}
}
/// <summary>
/// The Longitude coordinate of the point
/// </summary>
public double Latitude
{
get { return Point.Y; }
set
{
_Point.Y = value;
Point = _Point;
}
}
同时还为MapControl启用了硬件加速的支持，另外还优化了DeepEarth的内置控件，升级到Silverlighg 4后我们可以在VS2010或是Blend4中设计更佳美观、炫丽的UI效果。
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