高德地图开发（二）加载瓦片数据

官方Demo中给我们提供了加载在线瓦片数据的功能。
我们在上一节的基础上进行演示。话不多说先上图。

布局文件如下：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
   >
    <com.amap.api.maps.MapView
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
     <Button
        android:id="@+id/btn_tile"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/tile_data"
        />
</RelativeLayout>

MainActivity中都是按照Demo写的，就不多说了。

package com.example.maptest;

import android.app.Activity;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

import com.amap.api.maps.AMap;
import com.amap.api.maps.MapView;
import com.amap.api.maps.model.TileOverlay;
import com.amap.api.maps.model.TileOverlayOptions;
import com.amap.api.maps.model.UrlTileProvider;

import java.net.URL;

public class MainActivity extends Activity implements View.OnClickListener {
    private MapView mMapView;
    private Button btn_tile;
    private AMap aMap;
    private TileOverlay mtileOverlay;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mMapView = (MapView) findViewById(R.id.map);
        btn_tile = (Button) findViewById(R.id.btn_tile);
        //在activity执行onCreate时执行mMapView.onCreate(savedInstanceState)，创建地图
        mMapView.onCreate(savedInstanceState);
        if (aMap == null) {
            aMap = mMapView.getMap();
        }
         //移动中心点到西安
        aMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(34.341568, 108.940174), 10));

        btn_tile.setOnClickListener(this);
    }


    @Override
    protected void onDestroy() {
        super.onDestroy();
        //在activity执行onDestroy时执行mMapView.onDestroy()，销毁地图
        mMapView.onDestroy();
    }

    @Override
    protected void onResume() {
        super.onResume();
        //在activity执行onResume时执行mMapView.onResume ()，重新绘制加载地图
        mMapView.onResume();
    }

    @Override
    protected void onPause() {
        super.onPause();
        //在activity执行onPause时执行mMapView.onPause ()，暂停地图的绘制
        mMapView.onPause();
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        //在activity执行onSaveInstanceState时执行mMapView.onSaveInstanceState (outState)，
        //保存地图当前的状态
        mMapView.onSaveInstanceState(outState);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.btn_tile:
                if (mtileOverlay != null){
                    mtileOverlay.remove();
                }
                //在线瓦片数据
                useOMCMap();
                break;
        }
    }

    /**
     * 加载在线瓦片数据
     */
    private void useOMCMap() {
        final String url = "http://tile.opencyclemap.org/cycle/%d/%d/%d.png";
        TileOverlayOptions tileOverlayOptions = 
        new TileOverlayOptions().tileProvider(new UrlTileProvider(256, 256) {

            @Override
            public URL getTileUrl(int x, int y, int zoom) {
                try {
                    return new URL(String.format(url, zoom, x, y));
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return null;
            }
        });
        tileOverlayOptions.diskCacheEnabled(true)
                .diskCacheDir("/storage/emulated/0/amap/OMCcache")
                .diskCacheSize(100000)
                .memoryCacheEnabled(true)
                .memCacheSize(100000)
                .zIndex(-9999);
        mtileOverlay = aMap.addTileOverlay(tileOverlayOptions);
    }
}

官方介绍的是在线加载瓦片数据。下面我们来学习一下如何加载离线瓦片数据。
首先需要离线tiles文件，有兴趣的可以下载尝试。

tiles离线瓦片数据

然后将其复制到手机的根目录下。
和加载在线瓦片数据比较相似，只是路径变成了本地路径。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
   >
    <com.amap.api.maps.MapView
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
    <Button
        android:id="@+id/btn_tile"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/tile_data"
        />
    <Button
        android:layout_below="@+id/btn_tile"
        android:id="@+id/btn_offline_tile"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/offline_tile"
        />
    <Button
        android:layout_below="@+id/btn_offline_tile"
        android:id="@+id/btn_clear"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/clear"
        />
</RelativeLayout>

MainActivity代码

package com.example.maptest;

import android.app.Activity;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

import com.amap.api.maps.AMap;
import com.amap.api.maps.MapView;
import com.amap.api.maps.model.TileOverlay;
import com.amap.api.maps.model.TileOverlayOptions;
import com.amap.api.maps.model.UrlTileProvider;

import java.net.URL;

public class MainActivity extends Activity implements View.OnClickListener {
    private MapView mMapView;
    private Button btn_tile;
    private Button btn_offline_tile;
    private Button btn_clear;
    private AMap aMap;
    private TileOverlay mtileOverlay;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mMapView = (MapView) findViewById(R.id.map);
        btn_tile = (Button) findViewById(R.id.btn_tile);
        btn_offline_tile = (Button) findViewById(R.id.btn_offline_tile);
        btn_clear = (Button) findViewById(R.id.btn_clear);
        //在activity执行onCreate时执行mMapView.onCreate(savedInstanceState)，创建地图
        mMapView.onCreate(savedInstanceState);
        if (aMap == null) {
            aMap = mMapView.getMap();
        }
         //移动中心点到西安
        aMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(34.341568, 108.940174), 10));

        btn_tile.setOnClickListener(this);
        btn_offline_tile.setOnClickListener(this);
        btn_clear.setOnClickListener(this);
    }


    @Override
    protected void onDestroy() {
        super.onDestroy();
        //在activity执行onDestroy时执行mMapView.onDestroy()，销毁地图
        mMapView.onDestroy();
    }

    @Override
    protected void onResume() {
        super.onResume();
        //在activity执行onResume时执行mMapView.onResume ()，重新绘制加载地图
        mMapView.onResume();
    }

    @Override
    protected void onPause() {
        super.onPause();
        //在activity执行onPause时执行mMapView.onPause ()，暂停地图的绘制
        mMapView.onPause();
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        //在activity执行onSaveInstanceState时执行mMapView.onSaveInstanceState (outState)，
        //保存地图当前的状态
        mMapView.onSaveInstanceState(outState);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.btn_tile:
                if (mtileOverlay != null){
                    mtileOverlay.remove();
                }
                //在线瓦片数据
                useOMCMap();
                break;
            case R.id.btn_offline_tile:
                if (mtileOverlay != null){
                    mtileOverlay.remove();
                }
                //离线瓦片数据
                useOfflineTile();
                break;
            case R.id.btn_clear:
                //清除所有瓦片
                if (mtileOverlay != null){
                    mtileOverlay.remove();
                }
                break;

        }
    }

    /**
     * 加载在线瓦片数据
     */
    private void useOMCMap() {
        final String url = "http://tile.opencyclemap.org/cycle/%d/%d/%d.png";
        TileOverlayOptions tileOverlayOptions = 
        new TileOverlayOptions().tileProvider(new UrlTileProvider(256, 256) {

            @Override
            public URL getTileUrl(int x, int y, int zoom) {
                try {
                    return new URL(String.format(url, zoom, x, y));
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return null;
            }
        });
        tileOverlayOptions.diskCacheEnabled(true)
                .diskCacheDir("/storage/emulated/0/amap/OMCcache")
                .diskCacheSize(100000)
                .memoryCacheEnabled(true)
                .memCacheSize(100000)
                .zIndex(-9999);
        mtileOverlay = aMap.addTileOverlay(tileOverlayOptions);
    }

    /**
     * 加载离线瓦片数据
     */
    private void useOfflineTile() {
        final String url = "file:///storage/emulated/0/tiles/tiles/%d/%d/%d.jpg";
        TileOverlayOptions tileOverlayOptions = 
        new TileOverlayOptions().tileProvider(new UrlTileProvider(256, 256) {

            @Override
            public URL getTileUrl(int x, int y, int zoom) {
                try {
                    return new URL(String.format(url, zoom, x, y));
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return null;
            }
        });
        tileOverlayOptions.diskCacheEnabled(true)
                .diskCacheDir("/storage/emulated/0/amap/tilecache")
                .diskCacheSize(100000)
                .memoryCacheEnabled(true)
                .memCacheSize(100000)
                .zIndex(-9999);
        mtileOverlay = aMap.addTileOverlay(tileOverlayOptions);
    }


}