update2

@@ -14,6 +14,7 @@ import android.view.MenuItem;
 import com.esri.android.map.LocationDisplayManager;
 import com.esri.android.map.MapView;
 import com.esri.android.map.event.OnStatusChangedListener;
+import com.esri.android.map.event.OnZoomListener;
 import com.esri.android.runtime.ArcGISRuntime;
 import com.esri.core.geometry.Point;
 import com.pashanhoo.landsurvey.layers.tianditu.TDTTileinfo;
@@ -118,6 +119,20 @@ public class MainActivity extends AppCompatActivity {
                 }
             }
         });
+        mapView.setOnZoomListener(new OnZoomListener() {
+            @Override
+            public void preAction(float v, float v1, double v2) {
+            }
+
+            @Override
+            public void postAction(float v, float v1, double v2) {
+                Log.i("map", String.valueOf(TDTTileinfo.getCurrentLevel(mapView.getResolution())));
+                int level = TDTTileinfo.getCurrentLevel(mapView.getResolution());
+                if(level > 7 || level < 10){
+                    t_local.clearTiles();
+                }
+            }
+        });
 
         // GPS
         locationDisplayManager =  mapView.getLocationDisplayManager();

@@ -141,4 +141,13 @@ public class TDTTileinfo {
     public static int getTileHeight() {
         return tileHeight;
     }
+
+    public static int getCurrentLevel(double resolution){
+        for(int i=0; i< res4490.length;i++){
+            if((res4490[i] -resolution)<0.001){
+                return i;
+            }
+        }
+        return 0;
+    }
 }

@@ -78,7 +78,7 @@ public class TianDiTuLocalTiledMapServiceLayer extends TiledServiceLayer {
     private byte[] getOfflineCacheDB(int level, int col, int row) throws Exception {
 
         byte[] result = null;
-        Log.i("local", level + ":"+ col + ":" + row);
+//        Log.i("local", level + ":"+ col + ":" + row);
 //        row = (int) (Math.pow(2, level) - col - row);
         String sql = "select * from " + this.layername + " where TILELEVEL = " + level + " and TILECOL = " + col + " and TILEROW = " + row;