MyLocationOverlay - 自定义形象，但没影 [英] MyLocationOverlay - Custom image, but no shadow

问题描述

我有一个应用程序，它使用的自定义实现的 MyLocationOverlay 的

在我设置的时候已经指定它时使用的位图的财产，通过抽奖的重载的实现。

它工作得很好，用我的自定义图像，，但它不显示阴影 - 就像在自动完成的的 ItemizedOverlay 的

谁能帮助？

下面是（从有关code）我的类：

 公共类LocationOverlay：MyLocationOverlay
{
    ///＆所述;总结＆gt;位图用于指示当前的固定位置与所述; /总结＆gt;
    公共位图LocationMarker {搞定;组; }    ///＆LT;总结＆gt;如果已指定使用自定义标记位图。否则，则使用默认＆下; /总结＆gt;
    ///＆LT; PARAM NAME =画布＆GT;＆LT; /参数＆GT;
    ///＆LT; PARAM NAME =图形页面＆GT;＆LT; /参数＆GT;
    ///＆LT; PARAM NAME =影子＆GT;＆LT; /参数＆GT;
    ///＆LT; PARAM NAME =时，＆GT;＆LT; /参数＆GT;
    ///＆LT;＆回报GT;＆LT; /回报＆GT;
    公众覆盖布尔抽奖（帆布帆布，MapView类MapView类，布尔阴影，时长）
    {
        VAR drawShadow =阴影;        如果（LocationMarker = NULL＆放大器;！＆安培;！LastFix = NULL）
        {
            VAR screenPoint =新点（）;
            VAR的GeoPoint =新的GeoPoint（（INT）（LastFix.Latitude * 1E6），（INT）（LastFix.Longitude * 1E6））;
            mapView.Projection.ToPixels（GeoPoint对象，screenPoint）;
            canvas.DrawBitmap（LocationMarker，screenPoint.X，screenPoint.Y  -  32，NULL）;
            drawShadow = TRUE;
        }        base.Draw方法（画布，MapView类，drawShadow）;
        返回true;
    }
}
 

解决方案

明白了。您可以使用的 DrawAt 的自动绘制阴影。

所以，我的财产变成的绘制对象的正是如此：

 公众可绘制MarkerResource
{
    组
    {
        _locationMarker =价值;
        变种widthOffset = _locationMarker.IntrinsicWidth / 2;
        _locationMarker.SetBounds（-widthOffset，-_locationMarker.IntrinsicHeight，widthOffset，0）;
    }
}
 

和覆盖现在看起来是这样的：

 公共覆盖布尔抽奖（帆布帆布，MapView类MapView类，布尔阴影，时长）
{
    如果（LastFix == NULL）返回false;    如果（_locationMarker！= NULL）
    {
        VAR screenPoint =新点（）;
        VAR的GeoPoint =新的GeoPoint（（INT）（LastFix.Latitude * 1E6），（INT）（LastFix.Longitude * 1E6））;
        mapView.Projection.ToPixels（GeoPoint对象，screenPoint）;
        DrawAt（帆布，_locationMarker，screenPoint.X，screenPoint.Y，阴影）;
    }
    否则，如果（MyLocation！= NULL）DrawMyLocation（画布，MapView类，LastFix，MyLocation时）;    如果（IsCompassEnabled）DrawCompass（帆布，方向）;
    返回false;
}
 

完美的作品。

这现在也尊重使指南针，如果没有的<​​em>绘制对象的指定将借鉴使用默认的技术。

I have an application, which uses a custom implementation of MyLocationOverlay.

In the implementation I set a Bitmap property that is used when it has been specified, by an overload of Draw.

It works nicely, using my custom image, but it doesn't display a shadow - as is done automatically in an ItemizedOverlay.

Can anyone help?

Here is (the relevant code from) my class:

public class LocationOverlay: MyLocationOverlay
{
    /// <summary>Bitmap to use for indicating the current fixed location.</summary>
    public Bitmap LocationMarker { get; set; }

    /// <summary>Uses the custom marker bitmap if one has been specified. Otherwise, the default is used.</summary>
    /// <param name="canvas"></param>
    /// <param name="mapView"></param>
    /// <param name="shadow"></param>
    /// <param name="when"></param>
    /// <returns></returns>
    public override bool Draw(Canvas canvas, MapView mapView, bool shadow, long when)
    {
        var drawShadow = shadow;

        if (LocationMarker != null && LastFix != null)
        {
            var screenPoint = new Point();
            var geoPoint = new GeoPoint((int)(LastFix.Latitude * 1E6), (int)(LastFix.Longitude * 1E6));
            mapView.Projection.ToPixels(geoPoint, screenPoint);
            canvas.DrawBitmap(LocationMarker, screenPoint.X, screenPoint.Y - 32, null);
            drawShadow = true;
        }

        base.Draw(canvas, mapView, drawShadow);
        return true;
    }
}

解决方案

Got it. You can use DrawAt to draw the shadow automatically.

So my property becomes a Drawable thusly:

public Drawable MarkerResource
{
    set
    {
        _locationMarker = value;
        var widthOffset = _locationMarker.IntrinsicWidth / 2;
        _locationMarker.SetBounds(-widthOffset, -_locationMarker.IntrinsicHeight, widthOffset, 0);
    }
}

And the override now looks like this:

public override bool Draw(Canvas canvas, MapView mapView, bool shadow, long when)
{
    if (LastFix == null) return false;

    if (_locationMarker != null)
    {
        var screenPoint = new Point();
        var geoPoint = new GeoPoint((int)(LastFix.Latitude * 1E6), (int)(LastFix.Longitude * 1E6));
        mapView.Projection.ToPixels(geoPoint, screenPoint);
        DrawAt(canvas, _locationMarker, screenPoint.X, screenPoint.Y, shadow);
    }
    else if (MyLocation != null) DrawMyLocation(canvas, mapView, LastFix, MyLocation, when);

    if (IsCompassEnabled) DrawCompass(canvas, Orientation);
    return false;
}

Works perfectly.

This also now respects enabling the compass and will draw using the default technique if no Drawable is specified.

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