Java 在android中如何在谷歌地图上绘制网格？
我想创建一个类似于3字应用程序的网格。Java 在android中如何在谷歌地图上绘制网格？,java,android,google-maps,google-api,Java,Android,Google Maps,Google Api,我想创建一个类似于3字应用程序的网格。 一旦相机缩放到某个级别，网格就会显示出来，并随着用户的缩放进行缩放 我尝试了TileOverlay，并成功创建了一个网格。问题是网格在每次缩放时都会重新绘制自身。我希望网格不是重画，而是按照缩放级别缩放 然后我转到GroundOverlay并使用已经绘制的网格，我发现了两个问题：图像质量比原始图像差，并且像TileOverlay一样，它不随缩放而缩放 然后我尝试使用多边形绘制正方形，并使用（Map.getProjection（）.getVisibleRe
一旦相机缩放到某个级别，网格就会显示出来，并随着用户的缩放进行缩放 我尝试了
TileOverlayGroundOverlayTileOverlay（Map.getProjection（）.getVisibleRegion（））提前感谢。这是您可能已经尝试过的固定方法。总之，为每个网格大小创建形状（在本例中为小、中、大）；在主布局中创建视图，每个网格大小一个视图（所有可见性“消失”或一个可见）；创建一个类来扩展视图，以便可以平铺形状（我不知道如何在xml中设置平铺形状）；在此测试中，缩放侦听器在缩放<10（小）时更改“可见”视图；缩放=11（中等）；缩放>11（大） 首先是录音，然后是代码： 代码 形状
包装材料；
导入android.content.Context；
导入android.graphics.Bitmap；
导入android.graphics.Canvas；
导入android.graphics.Shader；
导入android.graphics.drawable.BitmapDrawable；
导入android.graphics.drawable.drawable；
导入android.util.AttributeSet；
导入android.view.view；
公共类GridView扩展了视图{
位图可绘制bm；
公共网格视图（上下文、属性集属性）{
超级（上下文，attrs）；
Drawable d=getBackground（）；
如果（d！=null）{
位图b=drawableToBitmap（d）；
bm=新的位图可绘制（getResources（），b）；
bm.setTileModeXY（Shader.TileMode.REPEAT，Shader.TileMode.REPEAT）；
}
}
@凌驾
受保护的void onDraw（画布）{
super.onDraw（帆布）；
bm.setBounds（canvas.getClipBounds（））；
绘画（画布）；
}
公共静态位图drawableToBitmap（可绘制）{
位图=空；
if（BitmapDrawable的可绘制实例）{
BitmapDrawable BitmapDrawable=（BitmapDrawable）drawable；
if（bitmapDrawable.getBitmap（）！=null）{
返回bitmapDrawable.getBitmap（）；
}
}
如果（drawable.getIntrinsicWidth（）确定，则此答案将演示绘制和移动网格的图形更新，以及使用w3w API对齐网格的尝试
因此，使用w3w的一个问题似乎是如何计算
由于算法显然是私有的，因此对于这个实现
“grid”restapi调用用于当前屏幕中心点（空闲时）和为候选参考点解析的json响应
在本例中，始终为“参考”网格单元绘制多边形
从w3w网格调用中获取
网格视图实现使用canvas.translate调用来正确对齐
并使用从参考点计算的偏移绘制栅格
由于使用SphereCalutil将距离映射到屏幕像素，因此这在任何纬度都有效
底部录音（低质量）
主要活动
在这里，w3w grid rest调用是在摄影机空闲时进行的，并将其放大到足够远的距离（无需在近距离缩放时保持重新对齐）和结果（附近网格单元的一个角点用作
参考点）输入栅格视图。绘制填充多边形以表示
参考网格单元
在相机移动时，使用相同的参考点，但使用当前屏幕位置来保持适当的偏移
public void what3words() {
// some initial default position
LatLng pt = new LatLng(38.547279, -121.461019);
mMap.setMapType(GoogleMap.MAP_TYPE_SATELLITE);
// move map to a coordinate
CameraUpdate cu = CameraUpdateFactory.newLatLng(pt);
mMap.moveCamera(cu);
cu = CameraUpdateFactory.zoomTo(14);
mMap.moveCamera(cu);
mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
@Override
public void onMapClick(LatLng latLng) {
mMap.addCircle(new CircleOptions().radius(4).strokeColor(Color.BLUE).center(latLng));
}
});
// while the camera is moving just move the grid (realign on idle)
mMap.setOnCameraMoveListener(new GoogleMap.OnCameraMoveListener() {
@Override
public void onCameraMove() {
((GridView) findViewById(R.id.grid_any)).setAlignment(
null, mMap.getProjection(), mMap.getProjection().getVisibleRegion());
}
});
// on idle fetch the grid using the screen center point
mMap.setOnCameraIdleListener(new GoogleMap.OnCameraIdleListener() {
@Override
public void onCameraIdle() {
Log.d(TAG,"idle");
final LatLng centerOfGridCell = mMap.getCameraPosition().target;
if (!gridSet || mMap.getCameraPosition().zoom < 10) {
getGrid(centerOfGridCell, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
Log.d(TAG, "reqpt: " + centerOfGridCell + " volley response: " + response);
try {
JSONObject jsonObject = new JSONObject(response);
JSONArray jsonArray = jsonObject.getJSONArray("lines");
JSONObject firstList = jsonArray.getJSONObject(1);
JSONObject firstPt = firstList.getJSONObject("start");
String lat = firstPt.getString("lat");
String lng = firstPt.getString("lng");
Log.d(TAG, "lat: " + lat + " lng: " + lng);
LatLng alignmentPt = new LatLng(Double.parseDouble(lat), Double.parseDouble(lng));
Projection p = mMap.getProjection();
VisibleRegion vr = p.getVisibleRegion();
((GridView) findViewById(R.id.grid_any)).setAlignment(alignmentPt, p, vr);
if (polygon != null) {
polygon.remove();
}
// take alignment point and draw 3 meter square polygon
LatLng pt1 = SphericalUtil.computeOffset(alignmentPt, 3, 90);
LatLng pt2 = SphericalUtil.computeOffset(pt1, 3, 180);
LatLng pt3 = SphericalUtil.computeOffset(pt2, 3, 270);
polygon = mMap.addPolygon(new PolygonOptions().add(alignmentPt,
pt1, pt2, pt3, alignmentPt)
.strokeColor(Color.BLUE).strokeWidth(4).fillColor(Color.BLUE));
} catch (Exception e) {
e.printStackTrace();
}
}
});
gridSet = true;
}
}
});
}
// Issue request to w3w - REMEMBER TO REPLACE **YOURKEY** ...
private void getGrid(LatLng pt, Response.Listener<String> listener) {
// something 9 meters to east
LatLng otherPt = SphericalUtil.computeOffset(pt, 6.0, 225);
String bboxStr = Double.toString(pt.latitude)+","+
Double.toString(pt.longitude)+","+
Double.toString(otherPt.latitude)+","+
Double.toString(otherPt.longitude);
RequestQueue rq = Volley.newRequestQueue(this);
String url = "https://api.what3words.com/v2/grid?bbox="+bboxStr+"&format=json&key=YOURKEY";
Log.d(TAG,"url="+url);
StringRequest req = new StringRequest(Request.Method.GET, url, listener, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "volley error: "+error);
}
});
rq.add(req);
}
public void what3words（）{
//一些初始默认位置
LatLng pt=新LatLng（38.547279，-121.461019）；
mMap.setMapType（GoogleMap.MAP_TYPE_卫星）；
//将地图移动到坐标
CameraUpdate cu=CameraUpdateFactory.newLatLng（pt）；
移动摄像机（cu）；
cu=CameraUpdateFactory.zoomTo（14）；
移动摄像机（cu）；
mMap.setOnMapClickListener（新的GoogleMap.OnMapClickListener（）{
@凌驾
公共无效的点击（LatLng LatLng）{
mMap.addCircle（新的CircleOptions（）.radius（4）、strokeColor（Color.BLUE）、center（latLng））；
}
});
//相机移动时，只需移动网格（空闲时重新对齐）
mMap.setOnCameraMoveListener（新的GoogleMap.OnCameraMoveListener（）{
@凌驾
关于CameraMove（）的公共无效{
（（GridView）findViewById（R.id.grid_any））.setAlignment(
null，mMap.getProjection（），mMap.getProjection（）.getVisibleRegion（）；
}
});
//空闲时，使用屏幕中心点提取网格
mMap.setonCameraideListener（新的GoogleMap.onCameraideListener（）{
@凌驾
公共无效OnCameradile（）{
Log.d（标记为“空闲”）；
最终LatLng centerOfGridCell=mMap.getCameraPosition（）.target；
如果（！gridSet | | mMap.getCameraPosition（）.zoom<10）{
getGrid（centerOfGridCell，new Response.Listener（））{
@凌驾
公众在
<RelativeLayout android:layout_height="match_parent" android:layout_width="match_parent"
xmlns:android="http://schemas.android.com/apk/res/android">
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:map="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="stuff.MapsActivity" />
<stuff.GridView
android:id="@+id/grid_small"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/grid_square_small"
android:visibility="visible"/>
<stuff.GridView
android:id="@+id/grid_medium"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/grid_square_medium"
android:visibility="gone"/>
<stuff.GridView
android:id="@+id/grid_large"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/grid_square_large"
android:visibility="gone"/>
</RelativeLayout>
package stuff;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Shader;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.View;
public class GridView extends View {
BitmapDrawable bm;
public GridView(Context context, AttributeSet attrs) {
super(context, attrs);
Drawable d= getBackground();
if (d != null) {
Bitmap b = drawableToBitmap(d);
bm = new BitmapDrawable(getResources(), b);
bm.setTileModeXY(Shader.TileMode.REPEAT, Shader.TileMode.REPEAT);
}
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
bm.setBounds(canvas.getClipBounds());
bm.draw(canvas);
}
public static Bitmap drawableToBitmap (Drawable drawable) {
Bitmap bitmap = null;
if (drawable instanceof BitmapDrawable) {
BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
if(bitmapDrawable.getBitmap() != null) {
return bitmapDrawable.getBitmap();
}
}
if(drawable.getIntrinsicWidth() <= 0 || drawable.getIntrinsicHeight() <= 0) {
bitmap = Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888); // Single color bitmap will be created of 1x1 pixel
} else {
bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
}
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
drawable.draw(canvas);
return bitmap;
}
}
int lastZoom = -1;
public void gridTest() {
mMap.setOnCameraMoveListener(new GoogleMap.OnCameraMoveListener() {
@Override
public void onCameraMove() {
int zoomInt = (int) mMap.getCameraPosition().zoom;
if (lastZoom == -1) {
lastZoom = zoomInt;
return;
}
Log.d(TAG, "zoom= "+zoomInt);
if (zoomInt < 10) {
findViewById(R.id.grid_small).setVisibility(View.VISIBLE);
findViewById(R.id.grid_medium).setVisibility(View.GONE);
findViewById(R.id.grid_large).setVisibility(View.GONE);
} else if (zoomInt < 11) {
findViewById(R.id.grid_small).setVisibility(View.GONE);
findViewById(R.id.grid_medium).setVisibility(View.VISIBLE);
findViewById(R.id.grid_large).setVisibility(View.GONE);
} else {
findViewById(R.id.grid_small).setVisibility(View.GONE);
findViewById(R.id.grid_medium).setVisibility(View.GONE);
findViewById(R.id.grid_large).setVisibility(View.VISIBLE);
}
lastZoom = zoomInt;
}
});
}
public void what3words() {
// some initial default position
LatLng pt = new LatLng(38.547279, -121.461019);
mMap.setMapType(GoogleMap.MAP_TYPE_SATELLITE);
// move map to a coordinate
CameraUpdate cu = CameraUpdateFactory.newLatLng(pt);
mMap.moveCamera(cu);
cu = CameraUpdateFactory.zoomTo(14);
mMap.moveCamera(cu);
mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
@Override
public void onMapClick(LatLng latLng) {
mMap.addCircle(new CircleOptions().radius(4).strokeColor(Color.BLUE).center(latLng));
}
});
// while the camera is moving just move the grid (realign on idle)
mMap.setOnCameraMoveListener(new GoogleMap.OnCameraMoveListener() {
@Override
public void onCameraMove() {
((GridView) findViewById(R.id.grid_any)).setAlignment(
null, mMap.getProjection(), mMap.getProjection().getVisibleRegion());
}
});
// on idle fetch the grid using the screen center point
mMap.setOnCameraIdleListener(new GoogleMap.OnCameraIdleListener() {
@Override
public void onCameraIdle() {
Log.d(TAG,"idle");
final LatLng centerOfGridCell = mMap.getCameraPosition().target;
if (!gridSet || mMap.getCameraPosition().zoom < 10) {
getGrid(centerOfGridCell, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
Log.d(TAG, "reqpt: " + centerOfGridCell + " volley response: " + response);
try {
JSONObject jsonObject = new JSONObject(response);
JSONArray jsonArray = jsonObject.getJSONArray("lines");
JSONObject firstList = jsonArray.getJSONObject(1);
JSONObject firstPt = firstList.getJSONObject("start");
String lat = firstPt.getString("lat");
String lng = firstPt.getString("lng");
Log.d(TAG, "lat: " + lat + " lng: " + lng);
LatLng alignmentPt = new LatLng(Double.parseDouble(lat), Double.parseDouble(lng));
Projection p = mMap.getProjection();
VisibleRegion vr = p.getVisibleRegion();
((GridView) findViewById(R.id.grid_any)).setAlignment(alignmentPt, p, vr);
if (polygon != null) {
polygon.remove();
}
// take alignment point and draw 3 meter square polygon
LatLng pt1 = SphericalUtil.computeOffset(alignmentPt, 3, 90);
LatLng pt2 = SphericalUtil.computeOffset(pt1, 3, 180);
LatLng pt3 = SphericalUtil.computeOffset(pt2, 3, 270);
polygon = mMap.addPolygon(new PolygonOptions().add(alignmentPt,
pt1, pt2, pt3, alignmentPt)
.strokeColor(Color.BLUE).strokeWidth(4).fillColor(Color.BLUE));
} catch (Exception e) {
e.printStackTrace();
}
}
});
gridSet = true;
}
}
});
}
// Issue request to w3w - REMEMBER TO REPLACE **YOURKEY** ...
private void getGrid(LatLng pt, Response.Listener<String> listener) {
// something 9 meters to east
LatLng otherPt = SphericalUtil.computeOffset(pt, 6.0, 225);
String bboxStr = Double.toString(pt.latitude)+","+
Double.toString(pt.longitude)+","+
Double.toString(otherPt.latitude)+","+
Double.toString(otherPt.longitude);
RequestQueue rq = Volley.newRequestQueue(this);
String url = "https://api.what3words.com/v2/grid?bbox="+bboxStr+"&format=json&key=YOURKEY";
Log.d(TAG,"url="+url);
StringRequest req = new StringRequest(Request.Method.GET, url, listener, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "volley error: "+error);
}
});
rq.add(req);
}
public class GridView extends View {
private static final String TAG = GridView.class.getSimpleName();
BitmapDrawable bm;
Bitmap bitmap;
GradientDrawable gd;
int offsetX = 0;
int offsetY = 0;
private int width = 16;
public GridView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public void setWidth(int w) {
width = w;
render();
invalidate();
}
private void render() {
setShape();
if (gd != null) {
bitmap = drawableToBitmap(gd);
bm = new BitmapDrawable(getResources(), bitmap);
bm.setTileModeXY(Shader.TileMode.REPEAT, Shader.TileMode.REPEAT);
bm.setBounds(0, 0, width, width);
}
}
Point startPt;
LatLng savedAlignmentPt;
public void setAlignment(LatLng alignmentPt, Projection p, VisibleRegion vr) {
if (alignmentPt == null) {
alignmentPt = savedAlignmentPt;
}
if (alignmentPt == null) {
return;
}
// the alignment point is the a corner of a grid square "near" the center of the screen
savedAlignmentPt = alignmentPt;
// compute how many screen pixels are in 3 meters using alignment point
startPt = p.toScreenLocation(alignmentPt);
LatLng upperRight = SphericalUtil.computeOffset(alignmentPt, 3, 90);
Point upperRtPt = p.toScreenLocation(upperRight);
int pixelsOf3meters = upperRtPt.x - startPt.x;
// don't draw grid if too small
if (pixelsOf3meters < 16) {
return;
}
setWidth(pixelsOf3meters);
// startPt is screen location of alignment point
offsetX = (pixelsOf3meters - (startPt.x % pixelsOf3meters));
offsetY = (pixelsOf3meters - (startPt.y % pixelsOf3meters));
invalidate();
}
private void setShape() {
int left, right, top, bottom;
gd = new GradientDrawable();
gd.setShape(GradientDrawable.RECTANGLE);
gd.setSize(width, width);
gd.setStroke(2, Color.argb(0xff, 0xcc, 0x22, 0x22));
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Rect rect = canvas.getClipBounds();
final int cWidth = canvas.getWidth();
final int cHeight = canvas.getHeight();
if (bm == null) {
return;
}
final Rect bmRect = bm.getBounds();
if (bmRect.width() <= 8 || bmRect.height() <= 8) {
return;
}
final int iterX = iterations(cWidth, -offsetX, bmRect.width());
final int iterY = iterations(cHeight, -offsetY, bmRect.height());
canvas.translate(-offsetX, -offsetY);
for (int x = 0; x < iterX; x++) {
for (int y = 0; y < iterY; y++) {
bm.draw(canvas);
canvas.translate(.0F, bmRect.height());
}
canvas.translate(bmRect.width(), -bmRect.height() * iterY);
}
}
private static int iterations(int total, int start, int side) {
final int diff = total - start;
final int base = diff / side;
return base + (diff % side > 0 ? 1 : 0);
}
public static Bitmap drawableToBitmap (Drawable drawable) {
Bitmap bitmap = null;
if (drawable instanceof BitmapDrawable) {
BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
if(bitmapDrawable.getBitmap() != null) {
return bitmapDrawable.getBitmap();
}
}
if(drawable.getIntrinsicWidth() <= 0 || drawable.getIntrinsicHeight() <= 0) {
bitmap = Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888); // Single color bitmap will be created of 1x1 pixel
} else {
bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
}
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
drawable.draw(canvas);
return bitmap;
}
}
// plot each point as a circle
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject startPt = jsonArray.getJSONObject(i).getJSONObject("start");
JSONObject endPt = jsonArray.getJSONObject(i).getJSONObject("end");
LatLng start = new LatLng(Double.parseDouble(startPt.getString("lat")), Double.parseDouble(startPt.getString("lng")));
LatLng end = new LatLng(Double.parseDouble(endPt.getString("lat")), Double.parseDouble(endPt.getString("lng")));
int c = colors[(i % colors.length)];
mMap.addCircle(new CircleOptions().center(start).strokeColor(c).fillColor(c).radius(1));
mMap.addCircle(new CircleOptions().center(end).strokeColor(Color.BLACK).fillColor(c).radius(1).strokeWidth(2));
Log.d(TAG, "d = "+SphericalUtil.computeDistanceBetween(start,end));
}
mMap.addCircle(new CircleOptions().center(centerOfGridCell).strokeColor(Color.WHITE).radius(1).strokeWidth(4));