地圖應用經常會涉及到線路的繪制問題，ios下可以使用MKMapView進行地圖開發，使用

MKOverlayView進行線路的繪制。

使用MKMapView添加MKMap.framework 和CoreLocation.framework并導入

MapKit.h頭文件。

新建一個基于視圖的工程，修改頭文件：

//
//  CloViewController.h
//  LocationMapTest
//
//  Created by Cloay on 12-6-18.
//  Copyright (c) 2012年 MyCompanyName. All rights reserved.
//

import <UIKIT uikit.h="">
import <MAPKIT mapkit.h="">
import "CloMKAnnotation.h"
@interface CloViewController : UIViewController<CLLOCATIONMANAGERDELEGATE, uiactionsheetdelegate="" mkmapviewdelegate,="">{
    MKMapView cloMapView;
    MKPolyline routeLine;
}
@property (nonatomic, strong)  NSMutableArray *locations;
@end</CLLOCATIONMANAGERDELEGATE,></mapkit></uikit></pre>

修改實現代碼，在.m中添加如下代碼： 

//
//  CloViewController.m
//  LocationMapTest
//
//  Created by Cloay on 12-6-18.
//  Copyright (c) 2012年 MyCompanyName. All rights reserved.
//

import "CloViewController.h"
@interface CloViewController ()
@end
@implementation CloViewController
@synthesize locations;

(void)viewDidLoad
{
  [super viewDidLoad];
  // Do any additional setup after loading the view, typically from a nib.
  cloMapView = [[MKMapView alloc] initWithFrame:[self.view bounds]];
  [cloMapView setMapType:MKMapTypeHybrid];  //設置地圖類型 地圖/衛星/兩者結合
  [cloMapView setShowsUserLocation:YES];      //顯示當前位置
  [cloMapView setDelegate:self];
CLLocationManager *locationManager = [[CLLocationManager alloc] init];
  //設置CLLocationManager實例委托和精度
  [locationManager setDelegate:self];
  [locationManager setDesiredAccuracy:kCLLocationAccuracyBest];
  //設置距離篩選器，表示至少移動100米才通知委托更新
  [locationManager setDistanceFilter:100.f];
  //啟動更新請求
//    [locationManager startUpdatingLocation];
locations = [[NSMutableArray alloc] init];
  float latitude = 39.8127;    //維度
  float longitude = 116.2967;  //經度
  for (int i = 0; i < 10; i++) {

  [locations addObject:[NSString stringWithFormat:@"%f,%f", latitude + 0.01*i, longitude + 0.01*i]];

//            NSLog(@"locations:%i",locations.count);
  }
//地圖初始
  CLLocationCoordinate2D coords;
  coords.latitude = 39.9127;
  coords.longitude = 116.3967;
  float zoomlevel = 0.22;
  MKCoordinateRegion region = MKCoordinateRegionMake(coords, MKCoordinateSpanMake(zoomlevel, zoomlevel));
  [cloMapView setRegion:[cloMapView regionThatFits:region] animated:YES];
[cloMapView addOverlay:[self makePolylineWithLocations:locations]];
  [self.view addSubview:cloMapView];


}

(void)viewDidUnload
{
  [super viewDidUnload];
  // Release any retained subviews of the main view.
  cloMapView = nil;
}

(void)dealloc{
  [cloMapView release];
  [super dealloc];
}

(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
  return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
}


//顯示菜單選項

(void)showActionSheet :(id)sender{
  UIActionSheet * actionSheet = [[UIActionSheet alloc] initWithTitle:nil 
                                                        delegate:self 
                                               cancelButtonTitle:@"取消"
                                          destructiveButtonTitle:@"添加足跡"
                                               otherButtonTitles:@"分享",@"詳細",@"刪除", nil];

  [actionSheet setDelegate:self];
  [actionSheet showInView:self.view];
  [actionSheet release];
}

//根據坐標點生成線路

(MKPolyline )makePolylineWithLocations:(NSMutableArray )newLocations{
  MKMapPoint pointArray = malloc(sizeof(CLLocationCoordinate2D) newLocations.count);
  for(int i = 0; i < newLocations.count; i++)

  {

  // break the string down even further to latitude and longitude fields.   
  NSString* currentPointString = [newLocations objectAtIndex:i];  
  NSArray* latLonArr = [currentPointString componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@","]];
  CLLocationDegrees latitude  = [[latLonArr objectAtIndex:0] doubleValue];  
  //        NSLog(@"latitude-> %f", latitude);
  CLLocationDegrees longitude = [[latLonArr objectAtIndex:1] doubleValue];  
  CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(latitude, longitude);  
  //        NSLog(@"point-> %f", point.x);

  if (i == 0 || i == locations.count - 1) {//這里只添加起點和終點作為測試
      CloMKAnnotation *ann = [[CloMKAnnotation alloc] init];
      [ann setCoordinate:coordinate];
      [ann setTitle:[NSString stringWithFormat:@"緯度:%f", latitude]];
      [ann setSubtitle:[NSString stringWithFormat:@"經度:%f", longitude]];
      [cloMapView addAnnotation:ann];
  }
  pointArray[i] = MKMapPointForCoordinate(coordinate);

}
routeLine = [MKPolyline polylineWithPoints:pointArray count:newLocations.count];
  free(pointArray);
  return routeLine;
}
#pragma mark-
#pragma CLLocationManager delegate method
//位置變化后會調用

(void)locationManager:(CLLocationManager )manager didUpdateToLocation:(CLLocation )newLocation fromLocation:(CLLocation *)oldLocation{
  //可在此處更新用戶位置信息
//    cloMapView.userLocation
  NSLog(@"oldLocation:%@", [oldLocation description]);
  NSLog(@"newLocation:%@", [newLocation description]);
  NSLog(@"distance:%@", [newLocation distanceFromLocation:oldLocation]);
  //位置變化添加新位置點
  [locations addObject:[NSString stringWithFormat:@"%f,%f", newLocation.coordinate.latitude, newLocation.coordinate.longitude]];
  //刪除進線路，更新新軌跡
  [cloMapView removeOverlay:routeLine];
  [cloMapView addOverlay:[self makePolylineWithLocations:locations]];

}
pragma MKMapView delegate method
//添加坐標點大頭針

(MKAnnotationView )mapView:(MKMapView )mapView viewForAnnotation:(id)annotation{
  if (![annotation isKindOfClass:[CloMKAnnotation class]]) {

  return nil;

}
  static NSString identifier = @"Annotation";
  MKPinAnnotationView pinAnnotationView = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
  if (pinAnnotationView == nil) {

  pinAnnotationView = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier] autorelease];

}
  pinAnnotationView.animatesDrop = YES;
  pinAnnotationView.canShowCallout = YES;
  pinAnnotationView.draggable = YES;
  UIButton *detailBtn = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
  [detailBtn addTarget:self action:@selector(showActionSheet:) forControlEvents:UIControlEventTouchUpInside];
  pinAnnotationView.rightCalloutAccessoryView = detailBtn;
return pinAnnotationView;
}

(void)mapView:(MKMapView )mapView annotationView:(MKAnnotationView )view didChangeDragState:(MKAnnotationViewDragState)newState fromOldState:(MKAnnotationViewDragState)oldState{


}
//畫線

(MKOverlayView )mapView:(MKMapView )mapView viewForOverlay:(id)overlay{
  NSLog(@"return overLayView...");
  if ([overlay isKindOfClass:[MKPolyline class]]) {
  MKPolylineView *routeLineView = [[[MKPolylineView alloc] initWithPolyline:routeLine] autorelease];
  routeLineView.strokeColor = [UIColor blueColor];
  routeLineView.lineWidth = 3;
  return routeLineView;

  }
  return nil;
}

@end</mkoverlay></mkannotation></pre>

這里主要是為了測試，初始時 locations坐標點自定義的，實際中是根據用戶的位置動態生成的一系列坐標點。具體可在 


- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
函數中實現，如上代碼。 

另外用戶的實時位置可用

cloMapView.userLocation = newLocation進行設置，然后顯示在地圖上。


效果圖如下： 


 


轉自：http://blog.csdn.net/shang_515/article/details/7676456