我试图在自定义 View 中绘制一些用于测试的东西,该 View 已添加到 GoogleMaps FragmentActivity。但不知何故,当我在模拟器中运行它时,我的 CustomView 似乎没有绘图。我尝试使用新的 RelativeLayout 和 MapLayout。有任何想法吗 ?我做错了什么?
这是我的主要 GoogleMaps FragmentActivity 代码,从 Android 模板自动生成:
public class GoogleMaps extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.google_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
//RelativeLayout relativeLayout = new RelativeLayout(this);
//relativeLayout.addView(new SpriteLayer(this));
MapView map = new MapView(this);
map.addView(new SpriteLayer(this));
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
// Add a marker in Sydney and move the camera
LatLng sydney = new LatLng(-34, 151);
mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
}
}
那是我的 CustomView 代码:
public class SpriteLayer extends View {
Paint paint = new Paint();
public SpriteLayer(Context context) {
super(context);
setWillNotDraw(false);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int desiredWidth = 100;
int desiredHeight = 100;
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int width;
int height;
//Measure Width
if (widthMode == MeasureSpec.EXACTLY) {
//Must be this size
width = widthSize;
} else if (widthMode == MeasureSpec.AT_MOST) {
//Can't be bigger than...
width = Math.min(desiredWidth, widthSize);
} else {
//Be whatever you want
width = desiredWidth;
}
//Measure Height
if (heightMode == MeasureSpec.EXACTLY) {
//Must be this size
height = heightSize;
} else if (heightMode == MeasureSpec.AT_MOST) {
//Can't be bigger than...
height = Math.min(desiredHeight, heightSize);
} else {
//Be whatever you want
height = desiredHeight;
}
//MUST CALL THIS
setMeasuredDimension(width, height);
}
@Override
public void onDraw(Canvas canvas) {
paint.setColor(Color.GREEN);
Rect rect = new Rect(20, 56, 200, 112);
canvas.drawRect(rect, paint );
Log.println(Log.ERROR,"Test ","One");
}
}
目前我只看到带有标记的标准 map ,仍然没有矩形 :(
最佳答案
您需要测量所需的 View 大小。你只是在传递你收到的东西,这可能是 0。
另一种选择是使用 MATCH_PARENT 设置 LayoutParams,但我不确定这是否可行。
你正在尝试做的是高级的,你应该在尝试之前阅读一些教程。
这里有更多信息:https://developer.android.com/training/custom-views/custom-drawing.html
关于java - Android/Java - 未显示 Google Maps FragmentActivity 上的自定义 View ,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/42163321/