坑
路線繪制完畢的時候，想要截圖，但是死活不能截取到完整的“起點”+“終點”圖片，即使在截圖之前將地圖的centerCoordinate設(shè)置成中點，然后設(shè)置2s延時后再截圖，也還是只能截取到以終點為中點的圖片。并不是設(shè)置center無效，地圖會閃一下中點的位置，然后還是回歸到終點的位置，然后截圖。但是！但是！當?shù)貓D加載后，我人為地拉動一下地圖，那么在截圖的時候，竟然可以設(shè)置中點成功，并截取到完整的圖片。這個問題糾結(jié)了一個禮拜。（問題看不懂的：我搜索了一下如何上傳視頻，但是貌似簡書的markdown不支持視頻，但是我又不想用回富文本，所以，只能用文字描述了。）
靈光一閃
今天突然想到將這個設(shè)置成no：_mapView.showsUserLocation = NO; 這樣的話，就需要自己實現(xiàn)定位圖片的一些功能，譬如箭頭圖標；設(shè)備運動方向變化的時候，箭頭要跟著指向前進的方向；還有就是隨著定位的變化而變化位置。
我猜想的是，百度地圖在我停止更新地點然后設(shè)置中點的時候，還會在某個回調(diào)中將當前位置設(shè)置成中點，但是拖動地圖打斷了它的這種回調(diào)。所以，我干脆就不讓它來幫我showUserLocation，我自己來顯示好了。這樣子一改，確實解決了問題。但是在模擬器上開車跑的時候(看本文“收獲”小節(jié))，結(jié)束定位來截圖的時候，還有可能會定位到當前位置，導(dǎo)致截圖不完整，但這個現(xiàn)象只出現(xiàn)了一次，然后無法重現(xiàn)，所以我暫時先不管了，畢竟我這個App是給用戶繪制走路路線的。
關(guān)鍵代碼
#pragma mark - update heading
-(void)BMKLocationManager:(BMKLocationManager *)manager didUpdateHeading:(CLHeading *)heading
{
//magneticHeading: 距離磁北方向的角度
//trueHeading: 真北
//headingAccuracy: 如果是負數(shù)，代表當前設(shè)備朝向不可用
if (heading.headingAccuracy < 0) {
return ;
}
if (!self.userLocation) {
self.userLocation = [[BMKUserLocation alloc] init];
}
self.userLocation.heading = heading;
[self.mapView updateLocationData:self.userLocation];
for (UIView *subView in self.arrowView.subviews) {
if ([subView isKindOfClass:[UIImageView class]] && subView.tag == 10000000) {
//角度，因為箭頭圖片向右方，所以逆時針轉(zhuǎn)90度
CLLocationDirection angle = heading.magneticHeading-90.f;
//順時針旋轉(zhuǎn)圖片（弧度）
subView.transform = CGAffineTransformMakeRotation(angle*M_PI/180.f);
}
}
}
#pragma mark - update location
-(void)BMKLocationManager:(BMKLocationManager *)manager didUpdateLocation:(BMKLocation *)location orError:(NSError *)error
{
if (error) {
NSLog(@"locError:{%ld - %@};", (long)error.code, error.localizedDescription);
}
if (!location) {
return ;
}
if (!self.userLocation) {
self.userLocation = [[BMKUserLocation alloc] init];
}
self.userLocation.location = location.location;
[self.mapView updateLocationData:self.userLocation];
//地圖放縮大小，4-21
self.mapView.zoomLevel = 21;
self.mapView.centerCoordinate = CLLocationCoordinate2DMake(self.userLocation.location.coordinate.latitude, self.userLocation.location.coordinate.longitude);
if (self.arrow) {
[self.mapView removeAnnotation:self.arrow];
}
BMKPointAnnotation *arrow = [[BMKPointAnnotation alloc] init];
arrow.coordinate = CLLocationCoordinate2DMake(self.userLocation.location.coordinate.latitude, self.userLocation.location.coordinate.longitude);
arrow.title = kArrowTitle;
[self.mapView addAnnotation:arrow];
self.arrow = arrow;
if(self.isStartTrace)
{
CGFloat distance = [self.userLocation.location distanceFromLocation:self.firstLocation.location];
if (distance < 10) {
return ;
}
CLLocationCoordinate2D coords[2] = {0};
coords[0].latitude = self.firstLocation.location.coordinate.latitude;
coords[0].longitude = self.firstLocation.location.coordinate.longitude;
coords[1].latitude = location.location.coordinate.latitude;
coords[1].longitude = location.location.coordinate.longitude;
//構(gòu)建分段顏色索引數(shù)組
BMKPolyline *polyline = [BMKPolyline polylineWithCoordinates:coords count:2];
[self.mapView addOverlay:polyline];
[self.points addObject:location];
self.firstLocation = [self.userLocation copy];
}
}
#pragma mark - 繪制軌跡點
-(void)drawTrackWithPoints:(NSArray *)points
{
NSLog(@"points: %@", points);
CLLocationCoordinate2D coors[points.count];
NSInteger cnt = 0;
for (size_t i = 0; i < points.count; i++) {
CLLocationCoordinate2D p = CLLocationCoordinate2DMake(((BMKLocation *)points[i]).location.coordinate.latitude, ((BMKLocation *)points[i]).location.coordinate.longitude);
coors[i] = p;
cnt++;
}
BMKPolyline *line = [BMKPolyline polylineWithCoordinates:coors count:cnt];
//起點annotation
BMKPointAnnotation *startAnnotation = [[BMKPointAnnotation alloc] init];
startAnnotation.coordinate = coors[0];
startAnnotation.title = kStartPositionTitle;
//終點annotation
BMKPointAnnotation *endAnnotation = [[BMKPointAnnotation alloc] init];
endAnnotation.coordinate = coors[cnt-1];
endAnnotation.title = kEndPositionTitle;
dispatch_async(MAIN_QUEUE, ^{
[self.mapView removeOverlays:self.mapView.overlays];
[self.mapView removeAnnotations:self.mapView.annotations];
[self mapViewFitForCoordinates:points];
[self.mapView addOverlay:line];
[self.mapView addAnnotation:startAnnotation];
[self.mapView addAnnotation:endAnnotation];
});
}
#pragma mark - 設(shè)置起點、終點和當前點樣式
-(BMKAnnotationView *)mapView:(BMKMapView *)mapView viewForAnnotation:(id<BMKAnnotation>)annotation
{
BMKAnnotationView *view = nil;
if ([annotation.title isEqualToString:kStartPositionTitle]) {
static NSString *startViewID = @"startAnnotationID";
view = [mapView dequeueReusableAnnotationViewWithIdentifier:startViewID];
if (view == nil) {
view = [[BMKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:startViewID];
UILabel *lbl = [self createLabel:@"始"];
[view addSubview:lbl];
}
}
else if([annotation.title isEqualToString:kEndPositionTitle]){
static NSString *endViewID = @"endAnnotationID";
view = [mapView dequeueReusableAnnotationViewWithIdentifier:endViewID];
if (view == nil) {
view = [[BMKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:endViewID];
UILabel *lbl = [self createLabel:@"終"];
[view addSubview:lbl];
}
}
else if([annotation.title isEqualToString:kArrowTitle]){
static NSString *runningArrowID = @"runningArrowAnnotationID";
view = [mapView dequeueReusableAnnotationViewWithIdentifier:runningArrowID];
if (view == nil) {
view = [[BMKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:runningArrowID];
view.frame = CGRectMake(0, 0, 22, 22);
view.draggable = NO;
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 22, 22)];
imageView.transform = CGAffineTransformMakeRotation((self.firstLocation.heading.magneticHeading-90.f)*M_PI/180.f);
imageView.image = [UIImage imageNamed:@"sportArrow.png"];
imageView.tag = 10000000;
[view addSubview:imageView];
}
self.arrowView = view;
}
return view;
}
-(UILabel *)createLabel:(NSString *)text
{
//label的frame x, y需要設(shè)置成-15，不然“始”會有一截沒有連線的
UILabel *lblStart = [[UILabel alloc] initWithFrame:CGRectMake(-15, -15, 30, 30)];
lblStart.backgroundColor = CSecondaryColor;
lblStart.font = [UIFont systemFontOfSize:14.0];
lblStart.textAlignment = NSTextAlignmentCenter;
lblStart.textColor = [UIColor whiteColor];
lblStart.layer.cornerRadius = 15;
lblStart.layer.borderWidth = 1;
lblStart.layer.masksToBounds = YES;
lblStart.layer.borderColor = [UIColor darkGrayColor].CGColor;
lblStart.text = text;
return lblStart;
}
-(void)mapViewFitForCoordinates:(NSArray *)points
{
double minLat = 90.0;
double maxLat = -90.0;
double minLon = 180.0;
double maxLon = -180.0;
for (size_t i = 0; i < points.count; i++) {
minLat = fmin(minLat, ((BMKLocation *)points[i]).location.coordinate.latitude);
maxLat = fmax(maxLat, ((BMKLocation *)points[i]).location.coordinate.latitude);
minLon = fmin(minLon, ((BMKLocation *)points[i]).location.coordinate.longitude);
maxLon = fmax(maxLon, ((BMKLocation *)points[i]).location.coordinate.longitude);
}
CLLocationCoordinate2D center = CLLocationCoordinate2DMake((minLat+maxLat)*0.5, (minLon+maxLon)*0.5);
BMKCoordinateSpan span;
span.latitudeDelta = 1.2 * ((maxLat-minLat)+0.01);
span.longitudeDelta = 1.2 * ((maxLon - minLon)+0.01);
BMKCoordinateRegion region;
region.center = center;
region.span = span;
[self.mapView setRegion:region animated:YES];
}
收獲
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使用百度地圖繪制路線，可以使用模擬器來進行模擬人的走動，或者車跑，或者自定義位置。
打開模擬器，去到導(dǎo)航欄，點擊Debug，如下圖，
模擬器模擬運動 我寫了NSMutableArray *overlays和annotations來存儲添加的層和線，原來mapview自己會保存，刪除的時候使用這個就OK了。
[self.mapView removeOverlays:self.mapView.overlays];
[self.mapView removeAnnotations:self.mapView.annotations];
