Pelabelan Sederhana

Pelabelan Sederhana menentukan bagaimana fitur harus diberi label.

Opsi yang didukung adalah:

Properti	Deskripsi
LabelAttribute	Menentukan nama atribut yang akan digunakan sebagai sumber label.
LabelExpression	Memberikan cara untuk menyesuaikan dan memformat teks label. Menggantikan LabelAttribute
FontFamily	Menentukan keluarga font yang akan digunakan untuk merender teks. Defaultnya adalah nilai yang bergantung pada sistem.
FontStyle	Gaya yang diterapkan ke teks. - FontStyle.Regular - teks biasa. - FontStyle.Bold - teks tebal. - FontStyle.Italic - teks miring. - FontStyle.Underine - teks bergaris bawah. - FontStyle.StrikeOut - teks dengan garis tengah.
FontSize	Menentukan ukuran teks.
FontColor	Menentukan warna teks.
HaloSize	Menentukan ukuran halo (atau garis luar) di sekitar teks.
HaloColor	Menentukan warna halo di sekitar teks.
GeometryExpression	Ekspresi geometri yang akan digunakan untuk mengubah geometri sebelum meneruskannya ke mesin pelabelan.
MultipartMode	Menentukan perilaku rendering untuk geometri multipart. - MultipartMode.All - tempatkan label di dekat setiap bagian dari geometri. - MultipartMode.Any - tempatkan satu label di dekat bagian mana pun dari geometri. - MultipartMode.Largest - tempatkan label di dekat bagian terbesar dari geometri.
Placement	Menentukan bagaimana label ditempatkan relatif terhadap geometri. - PointLabelPlacement - menempatkan label di dekat tengah geometri. - LineLabelPlacement - menempatkan label di sepanjang geometri atau perimeternya.
Priority	Menentukan prioritas label jika terjadi tumpang tindih dengan label lain. Label dengan prioritas lebih rendah tidak dirender. Defaultnya adalah 1000.

Contoh

Contoh Pelabelan Titik

Secara default, SimpleLabeling menggambar teks di atas titik:

	// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
	using (var map = new Map(500, 200))
	{
	var symbol = new SimpleMarker
	{
	FillColor = Color.LightGray,
	StrokeStyle = StrokeStyle.None
	};

	var labeling = new SimpleLabeling(labelAttribute: "name");

	map.Add(VectorLayer.Open(dataDir + "points.geojson", Drivers.GeoJson), symbol, labeling);
	map.Padding = 50;
	map.Render(dataDir + "points_labeling_out.svg", Renderers.Svg);
	}

view raw Examples-CSharp-Rendering-LabelMap-PointsLabeling.cs hosted with ❤ by GitHub

Berikut cara menata gaya font:

	// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
	using (var map = new Map(500, 200))
	{
	var symbol = new SimpleMarker
	{
	FillColor = Color.LightGray,
	StrokeStyle = StrokeStyle.None
	};

	var labeling = new SimpleLabeling(labelAttribute: "name")
	{
	HaloSize = 2,
	HaloColor = Color.LightGray,
	FontSize = 15,
	FontStyle = FontStyle.Italic,
	};

	map.Add(VectorLayer.Open(dataDir + "points.geojson", Drivers.GeoJson), symbol, labeling);
	map.Padding = 50;
	map.Render(dataDir + "points_labeling_styled_out.svg", Renderers.Svg);
	}

view raw Examples-CSharp-Rendering-LabelMap-PointsLabelingStyled.cs hosted with ❤ by GitHub

Untuk mengontrol posisi teks relatif terhadap fitur titik, properti penempatan harus diatur:

	// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
	using (var map = new Map(500, 200))
	{
	var symbol = new SimpleMarker
	{
	FillColor = Color.LightGray,
	StrokeStyle = StrokeStyle.None
	};

	var labeling = new SimpleLabeling(labelAttribute: "name")
	{
	HaloSize = 1,
	Placement = new PointLabelPlacement
	{
	VerticalAnchorPoint = VerticalAnchor.Bottom,
	HorizontalAnchorPoint = HorizontalAnchor.Left,
	HorizontalOffset = 2,
	VerticalOffset = 2,
	Rotation = 10,
	}
	};

	map.Add(VectorLayer.Open(dataDir + "points.geojson", Drivers.GeoJson), symbol, labeling);
	map.Padding = 50;
	map.Render(dataDir + "points_labeling_placed_out.svg", Renderers.Svg);
	}

view raw Examples-CSharp-Rendering-LabelMap-PointsLabelingPlaced.cs hosted with ❤ by GitHub

Untuk skenario yang lebih maju, Anda mungkin ingin memilih pelabelan yang berbeda untuk fitur. Berikut cara melakukannya:

	// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
	using (var map = new Map(500, 200))
	{
	var symbolizer = new SimpleMarker {FillColor = Color.LightGray, StrokeStyle = StrokeStyle.None};

	var labeling = new RuleBasedLabeling();
	// Set labeling to be used for small cities.
	labeling.Add(f => f.GetValue<int>("population") <= 2500, new SimpleLabeling("name")
	{
	FontStyle = FontStyle.Italic,
	HaloSize = 1,
	FontSize = 10,
	FontColor = Color.Green,
	Priority = 1,
	Placement = new PointLabelPlacement
	{
	VerticalAnchorPoint = VerticalAnchor.Bottom,
	HorizontalAnchorPoint = HorizontalAnchor.Center,
	}
	});
	// Set labeling to be used for all other cities.
	labeling.AddElseRule(new SimpleLabeling("name")
	{
	HaloSize = 1,
	FontSize = 15,
	FontColor = Color.Red,
	Priority = 2,
	Placement = new PointLabelPlacement
	{
	VerticalAnchorPoint = VerticalAnchor.Bottom,
	HorizontalAnchorPoint = HorizontalAnchor.Center,
	}
	});

	map.Add(VectorLayer.Open(dataDir + "points.geojson", Drivers.GeoJson), symbolizer, labeling);
	map.Padding = 40;
	map.Render(dataDir + "rule_based_labeling_out.svg", Renderers.Svg);
	}

view raw Examples-CSharp-Rendering-LabelMap-RuleBasedLabeling.cs hosted with ❤ by GitHub

Contoh Pelabelan Garis

Secara default, SimpleLabeling menggambar label di dekat tengah garis:

	// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
	using (var map = new Map(1000, 634))
	{
	var symbolizer = new SimpleLine { Width = 1.5, Color = Color.FromArgb(0xAE, 0xD9, 0xFD) };

	var labeling = new SimpleLabeling(labelAttribute: "name");

	map.Add(VectorLayer.Open(dataDir + "lines.geojson", Drivers.GeoJson), symbolizer, labeling);
	map.Padding = 50;
	map.Render(dataDir + "lines_labeling_out.svg", Renderers.Svg);
	}

view raw Examples-CSharp-Rendering-LabelMap-LinesLabeling.cs hosted with ❤ by GitHub

Untuk memutar label agar sejajar dengan garis, LineLabelPlacement dengan LineLabelAlignment.Parallel dapat digunakan:

	// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
	using (var map = new Map(1000, 634))
	{
	var symbolizer = new SimpleLine { Width = 1.5, Color = Color.FromArgb(0xAE, 0xD9, 0xFD) };

	var labeling = new SimpleLabeling(labelAttribute: "name")
	{
	HaloSize = 1,
	Placement = new LineLabelPlacement
	{
	Alignment = LineLabelAlignment.Parallel,
	}
	};

	map.Add(VectorLayer.Open(dataDir + "lines.geojson", Drivers.GeoJson), symbolizer, labeling);
	map.Padding = 50;
	map.Render(dataDir + "lines_labeling_parallel_out.svg", Renderers.Svg);
	}

view raw Examples-CSharp-Rendering-LabelMap-LinesLabelingParallel.cs hosted with ❤ by GitHub

Jika Anda ingin teks mengikuti garis secara tepat, LineLabelPlacement dengan LineLabelAlignment.Curved dapat digunakan:

	// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
	using (var map = new Map(1000, 634))
	{
	var symbolizer = new SimpleLine { Width = 1.5, Color = Color.FromArgb(0xAE, 0xD9, 0xFD) };

	var labeling = new SimpleLabeling(labelAttribute: "name")
	{
	HaloSize = 1,
	Placement = new LineLabelPlacement
	{
	Alignment = LineLabelAlignment.Curved,
	}
	};

	map.Add(VectorLayer.Open(dataDir + "lines.geojson", Drivers.GeoJson), symbolizer, labeling);
	map.Padding = 50;
	map.Render(dataDir + "lines_labeling_curved_out.svg", Renderers.Svg);
	}

view raw Examples-CSharp-Rendering-LabelMap-LinesLabelingCurved.cs hosted with ❤ by GitHub

Jika Anda tidak ingin teks tumpang tindih dengan garis, gunakan LineLabelPlacement.Offset:

	// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
	using (var map = new Map(1000, 634))
	{
	var symbolizer = new SimpleLine { Width = 1.5, Color = Color.FromArgb(0xAE, 0xD9, 0xFD) };

	var labeling = new SimpleLabeling(labelAttribute: "name")
	{
	HaloSize = 1,
	Placement = new LineLabelPlacement
	{
	Alignment = LineLabelAlignment.Curved,
	Offset = 5,
	}
	};

	map.Add(VectorLayer.Open(dataDir + "lines.geojson", Drivers.GeoJson), symbolizer, labeling);
	map.Padding = 50;
	map.Render(dataDir + "lines_labeling_curved_offset_out.svg", Renderers.Svg);
	}

view raw Examples-CSharp-Rendering-LabelMap-LinesLabelingCurvedWithOffset.cs hosted with ❤ by GitHub

Untuk skenario yang lebih maju, Anda mungkin ingin menyesuaikan gaya label secara dinamis berdasarkan nilai atribut fitur. Berikut cara melakukannya:

	// For complete examples and data files, please go to https://github.com/aspose-gis/Aspose.GIS-for-.NET
	using (var map = new Map(1000, 634))
	{
	var lineSymbolizer = new SimpleLine { Width = 1.5, Color = Color.FromArgb(0xae, 0xd9, 0xfd) };
	lineSymbolizer.FeatureBasedConfiguration = (feature, symbolizer) =>
	{
	if (feature.GetValue<string>("NAM") == "UNK")
	{
	symbolizer.Width = 1;
	symbolizer.Style = StrokeStyle.Dash;
	}
	};


	var lineLabeling = new SimpleLabeling(labelAttribute: "name")
	{
	HaloSize = 1,
	Placement = new LineLabelPlacement
	{
	Alignment = LineLabelAlignment.Parallel,
	},
	FontSize = 20,
	FeatureBasedConfiguration = (feature, labeling) =>
	{
	if (feature.GetValue<string>("NAM") == "UNK")
	{
	// change labeling properties for some features.
	labeling.FontStyle = FontStyle.Italic;
	labeling.FontSize = 10;
	labeling.Priority = -1;

	var placement = (LineLabelPlacement) labeling.Placement;
	placement.Alignment = LineLabelAlignment.Curved;
	placement.Offset = 5;
	}
	}
	};

	map.Add(VectorLayer.Open(dataDir + "lines.geojson", Drivers.GeoJson), lineSymbolizer, lineLabeling);
	map.Padding = 50;
	map.Render(dataDir + "lines_labeling_feature_based_out.svg", Renderers.Svg);
	}

view raw Examples-CSharp-Rendering-LabelMap-LinesLabelingFeatureBased.cs hosted with ❤ by GitHub

Pelabelan Berbasis Aturan