Vẽ đa giác trên bản đồ

Ví dụ này vẽ các đa giác có nhiều hình dạng và màu sắc khác nhau trên bản đồ.

Để biết thêm thông tin, hãy xem tài liệu này.

Bắt đầu

Bạn phải định cấu hình môi trường phát triển thì mới dùng thử được mã mẫu này. Để biết thêm thông tin, hãy xem SDK Maps dành cho mẫu Android.

Xem mã

Kotlin



override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.polygon_demo)

    fillHueBar = findViewById<SeekBar>(R.id.fillHueSeekBar).apply {
        max = MAX_HUE_DEGREES
        progress = MAX_HUE_DEGREES / 2
    }

    fillAlphaBar = findViewById<SeekBar>(R.id.fillAlphaSeekBar).apply {
        max = MAX_ALPHA
        progress = MAX_ALPHA / 2
    }

    strokeWidthBar = findViewById<SeekBar>(R.id.strokeWidthSeekBar).apply {
        max = MAX_WIDTH_PX
        progress = MAX_WIDTH_PX / 3
    }

    strokeHueBar = findViewById<SeekBar>(R.id.strokeHueSeekBar).apply {
        max = MAX_HUE_DEGREES
        progress = 0
    }

    strokeAlphaBar = findViewById<SeekBar>(R.id.strokeAlphaSeekBar).apply {
        max = MAX_ALPHA
        progress = MAX_ALPHA
    }

    strokeJointTypeSpinner = findViewById<Spinner>(R.id.strokeJointTypeSpinner).apply {
        adapter = ArrayAdapter(
                this@PolygonDemoActivity, android.R.layout.simple_spinner_item,
                getResourceStrings(jointTypeNameResourceIds))
    }

    strokePatternSpinner = findViewById<Spinner>(R.id.strokePatternSpinner).apply {
        adapter = ArrayAdapter(
                this@PolygonDemoActivity, android.R.layout.simple_spinner_item,
                getResourceStrings(patternTypeNameResourceIds))
    }

    clickabilityCheckbox = findViewById(R.id.toggleClickability)

    val mapFragment = supportFragmentManager.findFragmentById(R.id.map) as SupportMapFragment
    mapFragment.getMapAsync(this)
}

override fun onMapReady(googleMap: GoogleMap) {

    // return early if the map was not initialised properly
    googleMap ?: return

    val fillColorArgb = Color.HSVToColor(
            fillAlphaBar.progress, floatArrayOf(fillHueBar.progress.toFloat(), 1f, 1f))
    val strokeColorArgb = Color.HSVToColor(
            strokeAlphaBar.progress, floatArrayOf(strokeHueBar.progress.toFloat(), 1f, 1f))

    with(googleMap) {
        // Override the default content description on the view, for accessibility mode.
        setContentDescription(getString(R.string.polygon_demo_description))
        // Move the googleMap so that it is centered on the mutable polygon.
        moveCamera(CameraUpdateFactory.newLatLngZoom(center, 4f))

        // Create a rectangle with two rectangular holes.
        mutablePolygon = addPolygon(PolygonOptions().apply {
            addAll(createRectangle(center, 5.0, 5.0))
            addHole(createRectangle(LatLng(-22.0, 128.0), 1.0, 1.0))
            addHole(createRectangle(LatLng(-18.0, 133.0), 0.5, 1.5))
            fillColor(fillColorArgb)
            strokeColor(strokeColorArgb)
            strokeWidth(strokeWidthBar.progress.toFloat())
            clickable(clickabilityCheckbox.isChecked)
        })

        // Add a listener for polygon clicks that changes the clicked polygon's stroke color.
        setOnPolygonClickListener { polygon ->
            // Flip the red, green and blue components of the polygon's stroke color.
            polygon.strokeColor = polygon.strokeColor xor 0x00ffffff
        }
    }

    // set listeners on seekBars
    arrayOf(fillHueBar, fillAlphaBar, strokeWidthBar, strokeHueBar, strokeAlphaBar).map {
        it.setOnSeekBarChangeListener(this)
    }

    // set listeners on spinners
    arrayOf(strokeJointTypeSpinner, strokePatternSpinner).map {
        it.onItemSelectedListener = this
    }

    // set line pattern and joint type based on current spinner position
    with(mutablePolygon) {
        strokeJointType = getSelectedJointType(strokeJointTypeSpinner.selectedItemPosition)
        strokePattern = getSelectedPattern(strokePatternSpinner.selectedItemPosition)
    }

}

      

Java


public class PolygonDemoActivity extends AppCompatActivity
        implements OnSeekBarChangeListener, OnItemSelectedListener, OnMapReadyCallback {

    private static final LatLng CENTER = new LatLng(-20, 130);
    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 PATTERN_DASH_LENGTH_PX = 50;
    private static final int PATTERN_GAP_LENGTH_PX = 10;
    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 Polygon mutablePolygon;
    private SeekBar fillHueBar;
    private SeekBar fillAlphaBar;
    private SeekBar strokeWidthBar;
    private SeekBar strokeHueBar;
    private SeekBar strokeAlphaBar;
    private Spinner strokeJointTypeSpinner;
    private Spinner strokePatternSpinner;
    private CheckBox clickabilityCheckbox;

    // These are the options for polygon stroke joints and patterns. We use their
    // string resource IDs as identifiers.

    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.polygon_demo);

        fillHueBar = findViewById(R.id.fillHueSeekBar);
        fillHueBar.setMax(MAX_HUE_DEGREES);
        fillHueBar.setProgress(MAX_HUE_DEGREES / 2);

        fillAlphaBar = findViewById(R.id.fillAlphaSeekBar);
        fillAlphaBar.setMax(MAX_ALPHA);
        fillAlphaBar.setProgress(MAX_ALPHA / 2);

        strokeWidthBar = findViewById(R.id.strokeWidthSeekBar);
        strokeWidthBar.setMax(MAX_WIDTH_PX);
        strokeWidthBar.setProgress(MAX_WIDTH_PX / 3);

        strokeHueBar = findViewById(R.id.strokeHueSeekBar);
        strokeHueBar.setMax(MAX_HUE_DEGREES);
        strokeHueBar.setProgress(0);

        strokeAlphaBar = findViewById(R.id.strokeAlphaSeekBar);
        strokeAlphaBar.setMax(MAX_ALPHA);
        strokeAlphaBar.setProgress(MAX_ALPHA);

        strokeJointTypeSpinner = findViewById(R.id.strokeJointTypeSpinner);
        strokeJointTypeSpinner.setAdapter(new ArrayAdapter<>(
                this, android.R.layout.simple_spinner_item,
                getResourceStrings(JOINT_TYPE_NAME_RESOURCE_IDS)));

        strokePatternSpinner = findViewById(R.id.strokePatternSpinner);
        strokePatternSpinner.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.polygon_demo_description));

        int fillColorArgb = Color.HSVToColor(
                fillAlphaBar.getProgress(), new float[]{fillHueBar.getProgress(), 1, 1});
        int strokeColorArgb = Color.HSVToColor(
                strokeAlphaBar.getProgress(), new float[]{strokeHueBar.getProgress(), 1, 1});

        // Create a rectangle with two rectangular holes.
        mutablePolygon = map.addPolygon(new PolygonOptions()
                .addAll(createRectangle(CENTER, 5, 5))
                .addHole(createRectangle(new LatLng(-22, 128), 1, 1))
                .addHole(createRectangle(new LatLng(-18, 133), 0.5, 1.5))
                .fillColor(fillColorArgb)
                .strokeColor(strokeColorArgb)
                .strokeWidth(strokeWidthBar.getProgress())
                .clickable(clickabilityCheckbox.isChecked()));

        fillHueBar.setOnSeekBarChangeListener(this);
        fillAlphaBar.setOnSeekBarChangeListener(this);

        strokeWidthBar.setOnSeekBarChangeListener(this);
        strokeHueBar.setOnSeekBarChangeListener(this);
        strokeAlphaBar.setOnSeekBarChangeListener(this);

        strokeJointTypeSpinner.setOnItemSelectedListener(this);
        strokePatternSpinner.setOnItemSelectedListener(this);

        mutablePolygon.setStrokeJointType(getSelectedJointType(strokeJointTypeSpinner.getSelectedItemPosition()));
        mutablePolygon.setStrokePattern(getSelectedPattern(strokePatternSpinner.getSelectedItemPosition()));

        // Move the map so that it is centered on the mutable polygon.
        map.moveCamera(CameraUpdateFactory.newLatLngZoom(CENTER, 4));

        // Add a listener for polygon clicks that changes the clicked polygon's stroke color.
        map.setOnPolygonClickListener(new GoogleMap.OnPolygonClickListener() {
            @Override
            public void onPolygonClick(Polygon polygon) {
                // Flip the red, green and blue components of the polygon's stroke color.
                polygon.setStrokeColor(polygon.getStrokeColor() ^ 0x00ffffff);
            }
        });
    }

}

      

Sao chép và chạy mẫu

Bạn cần có Git để chạy mẫu này trên máy. Lệnh sau đây sẽ sao chép mẫu kho lưu trữ ứng dụng.

git clone git@github.com:googlemaps-samples/android-samples.git

Nhập dự án mẫu vào Android Studio:

  1. Trong Android Studio, chọn File > (Tệp >) Mới > Nhập dự án.
  2. Chuyển đến vị trí bạn đã lưu kho lưu trữ rồi chọn thư mục dự án cho Kotlin hoặc Java:

    • Kotlin: PATH-REPO/android-samples/ApiDemos/kotlin
    • Java: PATH-REPO/android-samples/ApiDemos/java
  3. Chọn Open (Mở). Android Studio sẽ tạo dự án của bạn bằng bản dựng Gradle .
  4. Tạo một tệp secrets.properties trống trong cùng thư mục với tệp local.properties của dự án. Để biết thêm thông tin, hãy xem phần Thêm khoá API vào dự án.
  5. Thêm chuỗi sau vào secrets.properties, thay thế YOUR_API_KEY bằng giá trị của khoá API của bạn:

    MAPS_API_KEY=YOUR_API_KEY
  6. Chạy ứng dụng.