百度地图之自定义绘制功能(一)

package com.home;  
  
import android.app.Activity;  
import android.os.Bundle;  
import android.view.View;  
import android.view.View.OnClickListener;  
import android.widget.Button;  
  
import com.baidu.mapapi.map.Geometry;  
import com.baidu.mapapi.map.Graphic;  
import com.baidu.mapapi.map.GraphicsOverlay;  
import com.baidu.mapapi.map.MapView;  
import com.baidu.mapapi.map.Symbol;  
import com.baidu.mapapi.map.TextItem;  
import com.baidu.mapapi.map.TextOverlay;  
import com.baidu.platform.comapi.basestruct.GeoPoint;  
  
/** 
 * 此demo用来展示如何在地图上用GraphicsOverlay添加点、线、多边形、圆 同时展示如何在地图上用TextOverlay添加文字 
 *  
 */  
public class GeometryActivity extends Activity implements OnClickListener {  
  
    // 地图相关  
    private MapView mMapView = null;  
  
    private Button resetBtn = null;  
    private Button clearBtn = null;  
  
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_geometry);  
        CharSequence titleLable = "自定义绘制功能";  
        setTitle(titleLable);  
  
        // 初始化地图  
        mMapView = (MapView) findViewById(R.id.bmapView);  
        mMapView.getController().setZoom(12.5f);  
        mMapView.getController().enableClick(true);  
  
        // UI初始化  
        clearBtn = (Button) findViewById(R.id.btn_clear);  
        resetBtn = (Button) findViewById(R.id.btn_reset);  
        clearBtn.setOnClickListener(this);  
        resetBtn.setOnClickListener(this);  
        resetBtn.setEnabled(false);  
  
        // 界面加载时添加绘制图层  
        addCustomElementsDemo();  
    }  
  
    @Override  
    public void onClick(View v) {  
        if (v == clearBtn) {  
            clearClick();  
            clear





Btn.setEnabled(false);  
            resetBtn.setEnabled(true);  
        }  
        if (v == resetBtn) {  
            resetClick();  
            clearBtn.setEnabled(true);  
            resetBtn.setEnabled(false);  
        }  
    }  
  
    /** 
     * 清除所有图层 
     */  
    public void clearClick() {  
        mMapView.getOverlays().clear();  
    }  
  
    /** 
     * 添加绘制元素 
     */  
    public void resetClick() {  
        addCustomElementsDemo();  
    }  
  
    /** 
     * 添加点、线、多边形、圆、文字 
     */  
    public void addCustomElementsDemo() {  
        GraphicsOverlay graphicsOverlay = new GraphicsOverlay(mMapView);  
        mMapView.getOverlays().add(graphicsOverlay);  
        // 添加点  
        graphicsOverlay.setData(drawPoint());  
        // 添加折线  
        graphicsOverlay.setData(drawLine());  
        // 添加多边形  
        graphicsOverlay.setData(drawPolygon());  
        // 添加圆  
        graphicsOverlay.setData(drawCircle());  
        // 绘制文字  
        TextOverlay textOverlay = new TextOverlay(mMapView);  
        mMapView.getOverlays().add(textOverlay);  
        textOverlay.addText(drawText());  
        // 执行地图刷新使生效  
        mMapView.refresh();  
    }  
  
    /** 
     * 绘制折线，该折线状态随地图状态变化 
     *  
     * @return 折线对象 
     */  
    public Graphic drawLine() {  
        double mLat = 39.97923;  
        double mLon = 116.357428;  
  
        int lat = (int) (mLat * 1E6);  
        int lon = (int) (mLon * 1E6);  
        GeoPoint pt1 = new GeoPoint(lat, lon);  
  
        mLat = 39.94923;  
        mLon = 116.397428;  
        lat = (int) (mLat * 1E6);  
        lon = (int) (mLon * 1E6);  
        GeoPoint pt2 = new GeoPoint(lat, lon);  
        mLat = 39.97923;  
        mLon = 116.437428;  
        lat = (int) (mLat * 1E6);  
        lon = (int) (mLon * 1E6);  
        GeoPoint pt3 = new GeoPoint(lat, lon);  
  
        // 构建线  
        Geometry lineGeometry = new Geometry();  
        // 设定折线点坐标  
        GeoPoint[] linePoints = new GeoPoint[3];  
        linePoints[0] = pt1;  
        linePoints[1] = pt2;  
        linePoin