如何在每次用户更改位置时使用toast进行通知

Question

每当用户更改位置时，我想通知用户。我在onLocationChanged中插入了吐司，但是toast.makeText上的makeText上有一条红线。它说

The method makeText(Context, CharSequence, int) in the type Toast is not applicable for the arguments (CurrentLocationOverlay, String, int)

然后我从

Toast.makeText(this,"Your current speed is :" +gps.getSpeed, Toast.LENGTH_SHORT).show()

to Toast.makeText(getBaseContext(),"Your current speed is :" +gps.getSpeed, Toast.LENGTH_SHORT).show().

然后它告诉我创建getBaseContext()方法。我甚至把它改成了getApplicationContext()。还是一样的答案。甚至把它改成了类名还是一样的

公共类CurrentLocationOverlay扩展MyLocationOverlay {

GPSTracker gps;

  @Override
  public synchronized void onLocationChanged(Location location) {
    super.onLocationChanged(location);
    Toast.makeText(this,"Your current speed is :" +gps.getSpeed(), 
              Toast.LENGTH_SHORT).show();


    // only move to new position if enabled and we are in an border-area
    if (mc != null && centerOnCurrentLocation && inZoomActiveArea(currentPoint)) {
      mc.animateTo(getMyLocation());

    }}
  }

Answer 1

我很确定getApplicationContext和getBaseContext可以在类扩展Activity时使用。

是否有可能扩展Activity并实现MyLocationOverlay?

Answer 2

特定的方法需要扩展Activity，然后才能实现getApplicationContect