iOS MKMapView縮放以顯示所有標記

我正在使用MKMapView並在地圖上繪製了幾個點。我已經使用了MKCoordinateRegion和MKCoordinateSpan圍繞其中一點實現縮放等 - 但這不是我想要的...iOS MKMapView縮放以顯示所有標記

我正在嘗試使用類似於JavaScript縮放功能的內容。所以我的所有觀點都應該對用戶可見。（在英國將會有大約10個點）我想把它們全部展示出來，或者如果大部分都在倫敦地區，放大到那裏。

有沒有辦法以編程方式解決這個問題？

來源

2010-08-08 Matt Facer

當然。您想要在註釋中找到最大和最小的緯度和經度值（您可以通過迭代map.annotations來完成），然後設置地圖以顯示所有這些值。

// pad our map by 10% around the farthest annotations 
#define MAP_PADDING 1.1 

// we'll make sure that our minimum vertical span is about a kilometer 
// there are ~111km to a degree of latitude. regionThatFits will take care of 
// longitude, which is more complicated, anyway. 
#define MINIMUM_VISIBLE_LATITUDE 0.01 

MKCoordinateRegion region; 
region.center.latitude = (minLatitude + maxLatitude)/2; 
region.center.longitude = (minLongitude + maxLongitude)/2; 

region.span.latitudeDelta = (maxLatitude - minLatitude) * MAP_PADDING; 

region.span.latitudeDelta = (region.span.latitudeDelta < MINIMUM_VISIBLE_LATITUDE) 
    ? MINIMUM_VISIBLE_LATITUDE 
    : region.span.latitudeDelta; 

region.span.longitudeDelta = (maxLongitude - minLongitude) * MAP_PADDING; 

MKCoordinateRegion scaledRegion = [map regionThatFits:region]; 
[map setRegion:scaledRegion animated:YES];

來源

2010-08-10 20:31:50

這是考慮到了，你是疊加到地圖上標註享有高度的改善（這樣註釋的頂部不會被切斷時，它的座標偏移量是在底部例）。或者進一步推廣，允許您以像素爲單位指定填充，而不是以百分比形式填充。它需要一個兩階段的過程來查找註釋的界限，然後進一步增加界限以考慮您的貼圖填充。

- (void) zoomToAnnotationsBounds:(NSArray *)annotations { 

CLLocationDegrees minLatitude = DBL_MAX; 
CLLocationDegrees maxLatitude = -DBL_MAX; 
CLLocationDegrees minLongitude = DBL_MAX; 
CLLocationDegrees maxLongitude = -DBL_MAX; 

for (MyAnnotation *annotation in annotations) { 
      double annotationLat = annotation.coordinate.latitude; 
      double annotationLong = annotation.coordinate.longitude; 
    minLatitude = fmin(annotationLat, minLatitude); 
    maxLatitude = fmax(annotationLat, maxLatitude); 
    minLongitude = fmin(annotationLong, minLongitude); 
    maxLongitude = fmax(annotationLong, maxLongitude); 
} 

    // See function below 
[self setMapRegionForMinLat:minLatitude minLong:minLongitude maxLat:maxLatitude maxLong:maxLongitude]; 

// If your markers were 40 in height and 20 in width, this would zoom the map to fit them perfectly. Note that there is a bug in mkmapview's set region which means it will snap the map to the nearest whole zoom level, so you will rarely get a perfect fit. But this will ensure a minimum padding. 
UIEdgeInsets mapPadding = UIEdgeInsetsMake(40.0, 10.0, 0.0, 10.0); 
CLLocationCoordinate2D relativeFromCoord = [self.mapView convertPoint:CGPointMake(0, 0) toCoordinateFromView:self.mapView]; 

// Calculate the additional lat/long required at the current zoom level to add the padding 
CLLocationCoordinate2D topCoord = [self.mapView convertPoint:CGPointMake(0, mapPadding.top) toCoordinateFromView:self.mapView]; 
CLLocationCoordinate2D rightCoord = [self.mapView convertPoint:CGPointMake(0, mapPadding.right) toCoordinateFromView:self.mapView]; 
CLLocationCoordinate2D bottomCoord = [self.mapView convertPoint:CGPointMake(0, mapPadding.bottom) toCoordinateFromView:self.mapView]; 
CLLocationCoordinate2D leftCoord = [self.mapView convertPoint:CGPointMake(0, mapPadding.left) toCoordinateFromView:self.mapView]; 

double latitudeSpanToBeAddedToTop = relativeFromCoord.latitude - topCoord.latitude; 
double longitudeSpanToBeAddedToRight = relativeFromCoord.latitude - rightCoord.latitude; 
double latitudeSpanToBeAddedToBottom = relativeFromCoord.latitude - bottomCoord.latitude; 
double longitudeSpanToBeAddedToLeft = relativeFromCoord.latitude - leftCoord.latitude; 

maxLatitude = maxLatitude + latitudeSpanToBeAddedToTop; 
minLatitude = minLatitude - latitudeSpanToBeAddedToBottom; 

maxLongitude = maxLongitude + longitudeSpanToBeAddedToRight; 
minLongitude = minLongitude - longitudeSpanToBeAddedToLeft; 

[self setMapRegionForMinLat:minLatitude minLong:minLongitude maxLat:maxLatitude maxLong:maxLongitude]; 
} 

-(void) setMapRegionForMinLat:(double)minLatitude minLong:(double)minLongitude maxLat:(double)maxLatitude maxLong:(double)maxLongitude { 

    MKCoordinateRegion region; 
    region.center.latitude = (minLatitude + maxLatitude)/2; 
    region.center.longitude = (minLongitude + maxLongitude)/2; 
    region.span.latitudeDelta = (maxLatitude - minLatitude); 
    region.span.longitudeDelta = (maxLongitude - minLongitude); 

    // MKMapView BUG: this snaps to the nearest whole zoom level, which is wrong- it doesn't respect the exact region you asked for. See http://stackoverflow.com/questions/1383296/why-mkmapview-region-is-different-than-requested 
    [self.mapView setRegion:region animated:YES]; 
}

來源

2011-02-26 11:02:52 Willster

如果只針對iOS的7個或更多，你現在可以使用：

- (void)showAnnotations:(NSArray *)annotations 
       animated:(BOOL)animated

來源

2013-12-04 09:04:45

所有完美的工作代碼修改的答案。

//Zooming the ploted Area 
- (void)zoomToAnnotationsBounds:(NSArray *)latLongArray { 
     __block CLLocationDegrees minLatitude = DBL_MAX; 
     __block CLLocationDegrees maxLatitude = -DBL_MAX; 
     __block CLLocationDegrees minLongitude = DBL_MAX; 
     __block CLLocationDegrees maxLongitude = -DBL_MAX; 

     [latLongArray enumerateObjectsUsingBlock:^(NSString *latLongObj, NSUInteger latLongIdx, BOOL *stop) { 
      latLongObj = [latLongArray objectAtIndex:latLongIdx]; 
      NSArray *latLongPoint = [latLongObj componentsSeparatedByString:@","]; 

      double annotationLat = [[latLongPoint objectAtIndex:0] doubleValue]; 
      double annotationLong = [[latLongPoint objectAtIndex:1] doubleValue]; 
      minLatitude = fmin(annotationLat, minLatitude); 
      maxLatitude = fmax(annotationLat, maxLatitude); 
      minLongitude = fmin(annotationLong, minLongitude); 
      maxLongitude = fmax(annotationLong, maxLongitude); 
     }]; 

     [self setMapRegionForMinLat:minLatitude minLong:minLongitude maxLat:maxLatitude maxLong:maxLongitude]; 
} 


-(void) setMapRegionForMinLat:(double)minLatitude minLong:(double)minLongitude maxLat:(double)maxLatitude maxLong:(double)maxLongitude { 

    // pad our map by 10% around the farthest annotations 

    // we'll make sure that our minimum vertical span is about a kilometer 
    // there are ~111km to a degree of latitude. regionThatFits will take care of 
    // longitude, which is more complicated, anyway. 

    MKCoordinateRegion region; 
    region.center.latitude = (minLatitude + maxLatitude)/2; 
    region.center.longitude = (minLongitude + maxLongitude)/2; 

    region.span.latitudeDelta = (maxLatitude - minLatitude) * MAP_PADDING; 

    region.span.latitudeDelta = (region.span.latitudeDelta < MINIMUM_VISIBLE_LATITUDE) 
    ? MINIMUM_VISIBLE_LATITUDE 
    : region.span.latitudeDelta; 

    region.span.longitudeDelta = (maxLongitude - minLongitude) * MAP_PADDING; 

    MKCoordinateRegion scaledRegion = [regionsMapView regionThatFits:region]; 
    [regionsMapView setRegion:scaledRegion animated:YES]; 

}

來源

2014-08-25 12:24:25

這是一個古老的問題，我知道你可能不需要任何幫助。但是我只是把它放在那裏，因爲任何正在尋找方法的人現在都可以使用MKMapView以上的新方法。它既乾淨又容易。

宣言

SWIFT
func showAnnotations(_ annotations: [AnyObject]!, 
      animated animated: Bool) 
Objective-C的
- (void)showAnnotations:(NSArray *)annotations 
       animated:(BOOL)animated 
參數

註解要在地圖上是可見的註釋。如果您希望地圖區域更改爲動畫，則爲動畫;如果您想讓地圖立即顯示新區域，則爲NO，否則爲無動畫。

討論

調用此方法更新該區域屬性的值和可能的其它屬性來反映新的地圖區域。

來源

2015-02-26 04:38:03 Matt

iOS MKMapView縮放以顯示所有標記

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