iPhone開發之繪制地圖線路

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並導入MapKit.h頭文件。

新建一個基於視圖的工程，修改頭文件：

1. //
2. // CloViewController.h
3. // LocationMapTest
4. //
5. // Created by Cloay on 12-6-18.
6. // Copyright (c) 2012年 __MyCompanyName__. All rights reserved.
7. //
9. #import <UIKit/UIKit.h>
10. #import <MapKit/MapKit.h>
11. #import "CloMKAnnotation.h"
12. @interface CloViewController : UIViewController<CLLocationManagerDelegate, MKMapViewDelegate, UIActionSheetDelegate>{
13. MKMapView *cloMapView;
14. MKPolyline *routeLine;
15. }
17. @property (nonatomic, strong) NSMutableArray *locations;
18. @end

修改實現代碼，在.m中添加如下代碼：

1. //
2. // CloViewController.m
3. // LocationMapTest
4. //
5. // Created by Cloay on 12-6-18.
6. // Copyright (c) 2012年 __MyCompanyName__. All rights reserved.
7. //
9. #import "CloViewController.h"
11. @interface CloViewController ()
13. @end
15. @implementation CloViewController
16. @synthesize locations;
18. - (void)viewDidLoad
19. {
20. [super viewDidLoad];
21. // Do any additional setup after loading the view, typically from a nib.
22. cloMapView = [[MKMapView alloc] initWithFrame:[self.view bounds]];
23. [cloMapView setMapType:MKMapTypeHybrid]; //設置地圖類型 地圖/衛星/兩者結合
24. [cloMapView setShowSUSErLocation:YES]; //顯示當前位置
25. [cloMapView setDelegate:self];
27. CLLocationManager *locationManager = [[CLLocationManager alloc] init];
28. //設置CLLocationManager實例委托和精度
29. [locationManager setDelegate:self];
30. [locationManager setDesiredAccuracy:kCLLocationAccuracyBest];
31. //設置距離篩選器，表示至少移動100米才通知委托更新
32. [locationManager setDistanceFilter:100.f];
33. //啟動更新請求
34. // [locationManager startUpdatingLocation];
36. locations = [[NSMutableArray alloc] init];
37. float latitude = 39.8127; //維度
38. float longitude = 116.2967; //經度
39. for (int i = 0; i < 10; i++) {
41. [locations addObject:[NSString stringWithFormat:@"%f,%f", latitude + 0.01*i, longitude + 0.01*i]];
42. // NSLog(@"locations:%i",locations.count);
43. }
45. //地圖初始
46. CLLocationCoordinate2D coords;
47. coords.latitude = 39.9127;
48. coords.longitude = 116.3967;
49. float zoomlevel = 0.22;
50. MKCoordinateRegion region = MKCoordinateRegionMake(coords, MKCoordinateSpanMake(zoomlevel, zoomlevel));
51. [cloMapView setRegion:[cloMapView regionThatFits:region] animated:YES];
53. [cloMapView addOverlay:[self makePolylineWithLocations:locations]];
54. [self.view addSubview:cloMapView];
56. }
58. - (void)viewDidUnload
59. {
60. [super viewDidUnload];
61. // Release any retained subviews of the main view.
62. cloMapView = nil;
63. }
65. - (void)dealloc{
66. [cloMapView release];
67. [super dealloc];
68. }
70. - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
71. {
72. return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);
73. }
76. //顯示菜單選項
77. - (void)showActionSheet :(id)sender{
78. UIActionSheet * actionSheet = [[UIActionSheet alloc] initWithTitle:nil
79. delegate:self
80. cancelButtonTitle:@"取消"
81. destructiveButtonTitle:@"添加足跡"
82. otherButtonTitles:@"分享",@"詳細",@"刪除", nil];
83. [actionSheet setDelegate:self];
84. [actionSheet showInView:self.view];
85. [actionSheet release];
86. }
88. //根據坐標點生成線路
89. - (MKPolyline *)makePolylineWithLocations:(NSMutableArray *)newLocations{
90. MKMapPoint *pointArray = malloc(sizeof(CLLocationCoordinate2D)* newLocations.count);
91. for(int i = 0; i < newLocations.count; i++)
92. {
93. // break the string down even further to latitude and longitude fields.
94. NSString* currentPointString = [newLocations objectAtIndex:i];
95. NSArray* latLonArr = [currentPointString componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@","]];
96. CLLocationDegrees latitude = [[latLonArr objectAtIndex:0] doubleValue];
97. // NSLog(@"latitude-> %f", latitude);
98. CLLocationDegrees longitude = [[latLonArr objectAtIndex:1] doubleValue];
99. CLLocationCoordinate2D coordinate = CLLocationCoordinate2DMake(latitude, longitude);
100. // NSLog(@"point-> %f", point.x);
102. if (i == 0 || i == locations.count - 1) {//這裡只添加起點和終點作為測試
103. CloMKAnnotation *ann = [[CloMKAnnotation alloc] init];
104. [ann setCoordinate:coordinate];
105. [ann setTitle:[NSString stringWithFormat:@"緯度:%f", latitude]];
106. [ann setSubtitle:[NSString stringWithFormat:@"經度:%f", longitude]];
107. [cloMapView addAnnotation:ann];
108. }
109. pointArray[i] = MKMapPointForCoordinate(coordinate);
110. }
112. routeLine = [MKPolyline polylineWithPoints:pointArray count:newLocations.count];
113. free(pointArray);
114. return routeLine;
115. }
116. #pragma mark-
117. #pragma CLLocationManager delegate method
118. //位置變化後會調用
119. - (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation{
120. //可在此處更新用戶位置信息
121. // cloMapView.userLocation
122. NSLog(@"oldLocation:%@", [oldLocation description]);
123. NSLog(@"newLocation:%@", [newLocation description]);
124. NSLog(@"distance:%@", [newLocation distanceFromLocation:oldLocation]);
125. //位置變化添加新位置點
126. [locations addObject:[NSString stringWithFormat:@"%f,%f", newLocation.coordinate.latitude, newLocation.coordinate.longitude]];
127. //刪除進線路，更新新軌跡
128. [cloMapView removeOverlay:routeLine];
129. [cloMapView addOverlay:[self makePolylineWithLocations:locations]];
131. }
133. #pragma MKMapView delegate method
134. //添加坐標點大頭針
135. - (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation{
136. if (![annotation isKindOfClass:[CloMKAnnotation class]]) {
137. return nil;
138. }
139. static NSString *identifier = @"Annotation";
140. MKPinAnnotationView *pinAnnotationView = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
141. if (pinAnnotationView == nil) {
142. pinAnnotationView = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier] autorelease];
143. }
144. pinAnnotationView.animatesDrop = YES;
145. pinAnnotationView.canShowCallout = YES;
146. pinAnnotationView.draggable = YES;
147. UIButton *detailBtn = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
148. [detailBtn addTarget:self action:@selector(showActionSheet:) forControlEvents:UIControlEventTouchUpInside];
149. pinAnnotationView.rightCalloutAccessoryView = detailBtn;
151. return pinAnnotationView;
152. }
154. - (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view didChangeDragState:(MKAnnotationViewDragState)newState fromOldState:(MKAnnotationViewDragState)oldState{
156. }
158. //畫線
159. - (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id<MKOverlay>)overlay{
160. NSLog(@"return overLayView...");
161. if ([overlay isKindOfClass:[MKPolyline class]]) {
162. MKPolylineView *routeLineView = [[[MKPolylineView alloc] initWithPolyline:routeLine] autorelease];
163. routeLineView.strokeColor = [UIColor blueColor];
164. routeLineView.lineWidth = 3;
165. return routeLineView;
166. }
167. return nil;
168. }
170. @end

這裡主要是為了測試，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

1. - (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

1. cloMapView.userLocation = newLocation進行設置，然後顯示在地圖上。

效果圖如下：