Question

我有一个在HoneyComb上运行良好的Android应用程序，但在ICS上运行不正常。我有谷歌地图，最重要的是我使用圆圈创建雷达效果（圆圈的半径不断增加给出一种水波效果。）代码如下：

class ShowRadar extends AsyncTask<Void, Void, RadarView>
        {

            private Context ctx;
            private int radius;
            private GeoPoint gp;
            private MapView mv;
            ShowRadar(Context ctxt, MapView mv, int radius, GeoPoint gp)
            {
                this.ctx = ctxt;
                this.radius = radius;
                this.gp = gp;
                this.mv = mv;
            }

            @Override
            protected RadarView doInBackground(Void... params) 
            {
                RadarView rdView = new RadarView(ctx, mv, gp, radius);
                LayoutParams lp = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
                rdView.setLayoutParams(lp);

                return rdView;
            }

            @Override
            protected void onPostExecute(RadarView result) {
                if(this.radius <= 10000)
                {
                    if(this.radius < 50)
                    {
                        this.radius += 50;
                    }
                    else if(this.radius < 100)
                    {
                        this.radius += 100;
                    }
                    else if(this.radius < 500)
                    {
                        this.radius += 500;
                    }
                    else
                    {
                        this.radius += 1000;
                    }
                }
                else
                    this.radius = 10;

                if(radarUpdated || radarCount > 1000)
                {
                    if(radarCount > 1000 && !radarUpdated)
                    {
                        Toast.makeText(mContext, "Delay in response, wait a while", Toast.LENGTH_SHORT).show();
                    }
                    radarCount = 0;
                    if (oldrd != null) {
                        rel.removeView(oldrd);
                        oldrd = null;
                    }

                }
                else
                {
                    radarCount++;

                    if(oldrd != null)
                    {
                        rel.removeView(oldrd);
                    }
                    oldrd = result;
                    rel.addView(result);

                    new ShowRadar(ctx, mv, this.radius, gp).execute();

                }
            }
        }
        new ShowRadar(mContext, mapView, 10, center).execute();

以下是RadarView的代码

  public class RadarView extends View {

private int circleRadius = 500;
private GeoPoint p;
public RadarView(Context context) {
 super(context);
 init();
}

public RadarView(Context context, MapView mv, GeoPoint pt, Integer radius)
{
    super(context);
    this.mapView = mv;
    this.p = pt;
    this.circleRadius = radius;
    init();
}

private void init(){
 paint = new Paint();
 paint.setColor(Color.GREEN);
 paint.setStrokeWidth(10);
 paint.setStyle(Paint.Style.STROKE);

}

@Override
protected void onDraw(Canvas canvas) {
 Projection projection = mapView.getProjection();
 Point pt = new Point();
 projection.toPixels(p, pt);

 float circleRadius = metersToRadius(this.circleRadius, mapView, (double)p.getLatitudeE6()/1E6);
 Paint circlePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
 circlePaint.setARGB(150, 12, 232, 91);
 circlePaint.setStyle(Style.STROKE);
 circlePaint.setStrokeWidth(10);
 if(canvas.isHardwareAccelerated())
 {
     mapView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
 }
 canvas.drawCircle((float)pt.x, (float)pt.y, circleRadius, circlePaint);

 super.onDraw(canvas);
}

 public static int metersToRadius(float meters, MapView map, double latitude) {
        return (int) (map.getProjection().metersToEquatorPixels(meters) * (1/ FloatMath.cos((float) Math.toRadians(latitude))));         
    }

}

我已经浏览了各种论坛，发现ICS默认激活了HardwareAcceleration，所以我在清单中添加了以下标记但没有帮助。任何人都可以告诉我这里出了什么问题。

 <application
    android:hardwareAccelerated="false"
    ....
</application>

Answer 1

我可以通过在android清单文件中将android：targetVersion更改为10来解决此问题。它不能使用API＆gt; = 11的原因是AsyncTask方法的行为发生了变化。看看Android AsyncTask not being called for minutes on ICS

Answer 2

Aspi Level中的AsycTask已经改变了执行机制，当你提到targetedSdk：10时，apk被编译为API级别10，因此dalvik机器将其视为。如果你想要更快的响应你使用以下API级别＆gt; 10

的程序

http://developer.android.com/reference/android/os/AsyncTask.html#executeOnExecutor(java.util.concurrent.Executor,Params...)

Answer 3

我对targetSDKVersion 13或更低版本有同样的问题。圆圈没有出现。

禁用视图硬件加速的解决方案。显然，drawCircle函数不适用于pre ICS上的accel。我将以下行添加到我的视图的init函数中：

setLayerType(View.LAYER_TYPE_SOFTWARE,null);

Android视图/画布drawCircle问题与ICS

3 个答案: