下例会在地图上添加和配置多段线，例如在地图上表示导航路线。
如需了解详情，请参阅相关文档。
开始使用
您必须先配置开发环境，然后才能试用该示例代码。如需了解详情，请参阅 Maps SDK for Android 代码示例。
查看代码
Kotlin
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.polyline_demo)
hueBar = findViewById<SeekBar>(R.id.hueSeekBar).apply {
max = MAX_HUE_DEGREES
progress = 0
}
alphaBar = findViewById<SeekBar>(R.id.alphaSeekBar).apply {
max = MAX_ALPHA
progress = MAX_ALPHA
}
widthBar = findViewById<SeekBar>(R.id.widthSeekBar).apply {
max = MAX_WIDTH_PX
progress = MAX_WIDTH_PX / 2
}
startCapSpinner = findViewById<Spinner>(R.id.startCapSpinner).apply {
adapter = ArrayAdapter(this@PolylineDemoActivity,
android.R.layout.simple_spinner_item,
getResourceStrings(capTypeNameResourceIds))
}
endCapSpinner = findViewById<Spinner>(R.id.endCapSpinner).apply {
adapter = ArrayAdapter(this@PolylineDemoActivity,
android.R.layout.simple_spinner_item,
getResourceStrings(capTypeNameResourceIds))
}
jointTypeSpinner = findViewById<Spinner>(R.id.jointTypeSpinner).apply {
adapter = ArrayAdapter(this@PolylineDemoActivity,
android.R.layout.simple_spinner_item,
getResourceStrings(jointTypeNameResourceIds))
}
patternSpinner = findViewById<Spinner>(R.id.patternSpinner).apply {
adapter = ArrayAdapter(
this@PolylineDemoActivity, android.R.layout.simple_spinner_item,
getResourceStrings(patternTypeNameResourceIds))
}
clickabilityCheckbox = findViewById<CheckBox>(R.id.toggleClickability)
val mapFragment = supportFragmentManager.findFragmentById(R.id.map) as SupportMapFragment
mapFragment.getMapAsync(this)
}
override fun onMapReady(googleMap: GoogleMap) {
googleMap
with(googleMap) {
// Override the default content description on the view, for accessibility mode.
setContentDescription(getString(R.string.polyline_demo_description))
// A geodesic polyline that goes around the world.
addPolyline(PolylineOptions().apply {
add(lhrLatLng, aklLatLng, laxLatLng, jfkLatLng, lhrLatLng)
width(INITIAL_STROKE_WIDTH_PX.toFloat())
color(Color.BLUE)
geodesic(true)
clickable(clickabilityCheckbox.isChecked)
})
// Move the googleMap so that it is centered on the mutable polyline.
moveCamera(CameraUpdateFactory.newLatLngZoom(melbourneLatLng, 3f))
// Add a listener for polyline clicks that changes the clicked polyline's color.
setOnPolylineClickListener { polyline ->
// Flip the values of the red, green and blue components of the polyline's color.
polyline.color = polyline.color xor 0x00ffffff
}
}
// A simple polyline across Australia. This polyline will be mutable.
mutablePolyline = googleMap.addPolyline(PolylineOptions().apply{
color(Color.HSVToColor(
alphaBar.progress, floatArrayOf(hueBar.progress.toFloat(), 1f, 1f)))
width(widthBar.progress.toFloat())
clickable(clickabilityCheckbox.isChecked)
add(melbourneLatLng, adelaideLatLng, perthLatLng, darwinLatLng)
})
arrayOf(hueBar, alphaBar, widthBar).map {
it.setOnSeekBarChangeListener(this)
}
arrayOf(startCapSpinner, endCapSpinner, jointTypeSpinner, patternSpinner).map {
it.onItemSelectedListener = this
}
with(mutablePolyline) {
startCap = getSelectedCap(startCapSpinner.selectedItemPosition) ?: ButtCap()
endCap = getSelectedCap(endCapSpinner.selectedItemPosition) ?: ButtCap()
jointType = getSelectedJointType(jointTypeSpinner.selectedItemPosition)
pattern = getSelectedPattern(patternSpinner.selectedItemPosition)
}
clickabilityCheckbox.setOnClickListener {
view -> mutablePolyline.isClickable = (view as CheckBox).isChecked
}
}
Java
public class PolylineDemoActivity extends AppCompatActivity
implements OnSeekBarChangeListener, OnItemSelectedListener, OnMapReadyCallback {
// City locations for mutable polyline.
private static final LatLng ADELAIDE = new LatLng(-34.92873, 138.59995);
private static final LatLng DARWIN = new LatLng(-12.4258647, 130.7932231);
private static final LatLng MELBOURNE = new LatLng(-37.81319, 144.96298);
private static final LatLng PERTH = new LatLng(-31.95285, 115.85734);
// Airport locations for geodesic polyline.
private static final LatLng AKL = new LatLng(-37.006254, 174.783018);
private static final LatLng JFK = new LatLng(40.641051, -73.777485);
private static final LatLng LAX = new LatLng(33.936524, -118.377686);
private static final LatLng LHR = new LatLng(51.471547, -0.460052);
private static final int MAX_WIDTH_PX = 100;
private static final int MAX_HUE_DEGREES = 360;
private static final int MAX_ALPHA = 255;
private static final int CUSTOM_CAP_IMAGE_REF_WIDTH_PX = 50;
private static final int INITIAL_STROKE_WIDTH_PX = 5;
private static final int PATTERN_DASH_LENGTH_PX = 50;
private static final int PATTERN_GAP_LENGTH_PX = 20;
private static final Dot DOT = new Dot();
private static final Dash DASH = new Dash(PATTERN_DASH_LENGTH_PX);
private static final Gap GAP = new Gap(PATTERN_GAP_LENGTH_PX);
private static final List<PatternItem> PATTERN_DOTTED = Arrays.asList(DOT, GAP);
private static final List<PatternItem> PATTERN_DASHED = Arrays.asList(DASH, GAP);
private static final List<PatternItem> PATTERN_MIXED = Arrays.asList(DOT, GAP, DOT, DASH, GAP);
private Polyline mutablePolyline;
private SeekBar hueBar;
private SeekBar alphaBar;
private SeekBar widthBar;
private Spinner startCapSpinner;
private Spinner endCapSpinner;
private Spinner jointTypeSpinner;
private Spinner patternSpinner;
private CheckBox clickabilityCheckbox;
// These are the options for polyline caps, joints and patterns. We use their
// string resource IDs as identifiers.
private static final int[] CAP_TYPE_NAME_RESOURCE_IDS = {
R.string.cap_butt, // Default
R.string.cap_round,
R.string.cap_square,
R.string.cap_image,
};
private static final int[] JOINT_TYPE_NAME_RESOURCE_IDS = {
R.string.joint_type_default, // Default
R.string.joint_type_bevel,
R.string.joint_type_round,
};
private static final int[] PATTERN_TYPE_NAME_RESOURCE_IDS = {
R.string.pattern_solid, // Default
R.string.pattern_dashed,
R.string.pattern_dotted,
R.string.pattern_mixed,
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.polyline_demo);
hueBar = findViewById(R.id.hueSeekBar);
hueBar.setMax(MAX_HUE_DEGREES);
hueBar.setProgress(0);
alphaBar = findViewById(R.id.alphaSeekBar);
alphaBar.setMax(MAX_ALPHA);
alphaBar.setProgress(MAX_ALPHA);
widthBar = findViewById(R.id.widthSeekBar);
widthBar.setMax(MAX_WIDTH_PX);
widthBar.setProgress(MAX_WIDTH_PX / 2);
startCapSpinner = findViewById(R.id.startCapSpinner);
startCapSpinner.setAdapter(new ArrayAdapter<>(
this, android.R.layout.simple_spinner_item,
getResourceStrings(CAP_TYPE_NAME_RESOURCE_IDS)));
endCapSpinner = findViewById(R.id.endCapSpinner);
endCapSpinner.setAdapter(new ArrayAdapter<>(
this, android.R.layout.simple_spinner_item,
getResourceStrings(CAP_TYPE_NAME_RESOURCE_IDS)));
jointTypeSpinner = findViewById(R.id.jointTypeSpinner);
jointTypeSpinner.setAdapter(new ArrayAdapter<>(
this, android.R.layout.simple_spinner_item,
getResourceStrings(JOINT_TYPE_NAME_RESOURCE_IDS)));
patternSpinner = findViewById(R.id.patternSpinner);
patternSpinner.setAdapter(new ArrayAdapter<>(
this, android.R.layout.simple_spinner_item,
getResourceStrings(PATTERN_TYPE_NAME_RESOURCE_IDS)));
clickabilityCheckbox = findViewById(R.id.toggleClickability);
SupportMapFragment mapFragment =
(SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
@Override
public void onMapReady(GoogleMap map) {
// Override the default content description on the view, for accessibility mode.
map.setContentDescription(getString(R.string.polyline_demo_description));
// A geodesic polyline that goes around the world.
map.addPolyline(new PolylineOptions()
.add(LHR, AKL, LAX, JFK, LHR)
.width(INITIAL_STROKE_WIDTH_PX)
.color(Color.BLUE)
.geodesic(true)
.clickable(clickabilityCheckbox.isChecked()));
// A simple polyline across Australia. This polyline will be mutable.
int color = Color.HSVToColor(
alphaBar.getProgress(), new float[]{hueBar.getProgress(), 1, 1});
mutablePolyline = map.addPolyline(new PolylineOptions()
.color(color)
.width(widthBar.getProgress())
.clickable(clickabilityCheckbox.isChecked())
.add(MELBOURNE, ADELAIDE, PERTH, DARWIN));
hueBar.setOnSeekBarChangeListener(this);
alphaBar.setOnSeekBarChangeListener(this);
widthBar.setOnSeekBarChangeListener(this);
startCapSpinner.setOnItemSelectedListener(this);
endCapSpinner.setOnItemSelectedListener(this);
jointTypeSpinner.setOnItemSelectedListener(this);
patternSpinner.setOnItemSelectedListener(this);
mutablePolyline.setStartCap(getSelectedCap(startCapSpinner.getSelectedItemPosition()));
mutablePolyline.setEndCap(getSelectedCap(endCapSpinner.getSelectedItemPosition()));
mutablePolyline.setJointType(getSelectedJointType(jointTypeSpinner.getSelectedItemPosition()));
mutablePolyline.setPattern(getSelectedPattern(patternSpinner.getSelectedItemPosition()));
// Move the map so that it is centered on the mutable polyline.
map.moveCamera(CameraUpdateFactory.newLatLngZoom(MELBOURNE, 3));
// Add a listener for polyline clicks that changes the clicked polyline's color.
map.setOnPolylineClickListener(new GoogleMap.OnPolylineClickListener() {
@Override
public void onPolylineClick(Polyline polyline) {
// Flip the values of the red, green and blue components of the polyline's color.
polyline.setColor(polyline.getColor() ^ 0x00ffffff);
}
});
}
}
克隆并运行示例
您必须拥有 Git，才能在本地运行此示例。以下命令会克隆示例应用代码库。
git clone git@github.com:googlemaps-samples/android-samples.git
将示例项目导入到 Android Studio：
- 在 Android Studio 中，依次选择 File > New > Import Project。
前往代码库的保存位置并选择 Kotlin 或 Java 的项目目录：
- Kotlin：
PATH-REPO/android-samples/ApiDemos/kotlin - Java：
PATH-REPO/android-samples/ApiDemos/java
- Kotlin：
- 选择 Open。Android Studio 会使用 Gradle 构建工具来构建您的项目。
- 在项目的
local.properties文件所在的同一目录中，创建一个空白secrets.properties文件。如需了解详情，请参阅将您的 API 密钥添加到项目中。 在
secrets.properties中添加以下字符串，并将 YOUR_API_KEY 替换为您的 API 密钥的值：MAPS_API_KEY=YOUR_API_KEY- 运行应用。