Question

我在地图上为用户位置设置自定义图像，如下所示：

func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView? {

    if annotation.isEqual(mapView.userLocation) {

        let identifier = "User"

        var annotationView = mapView.dequeueReusableAnnotationViewWithIdentifier(identifier)

        if annotationView == nil{
            annotationView = CustomPointAnnotation(annotation: annotation, reuseIdentifier: identifier)
            annotationView!.canShowCallout = true

        } else {
            annotationView!.annotation = annotation
        }

        annotationView!.image = UIImage(named: userImage)

        return annotationView

    }
    return nil
}

我已经更改了图像属性，如何告诉地图更新MKAnnotationView？

Answer 1

我认为你想要删除注释然后重新添加它们，这将迫使地图更新。直接编辑现有注释不会强制重绘地图。

Answer 2

此解决方案适合我：

let userLocation = mapView.view(for: mapView.userLocation)
userLocation?.image = UIImage(named: "newImage")
userLocation?.isHidden = true
userLocation?.isHidden = false

Answer 3

我的答案之一-https://stackoverflow.com/a/57868438/7505665

我有类似的问题，我的情况下的解决方案是这段代码

import multiprocessing
import numpy as np
import pandas pd

size = 100000
cols = list('abcdefghijklmnopqrstuvwxyz')
n_core = muliprocessing.cpu_count()

def format_col(col):
    return col, ["%s_%d" % (col, n) for n in np.arange(size)]

with multiprocessing.Pool(n_core) as pool:
    result = {}
    for res in pool.map(format_col, cols):
        result[res[0]]=res[1]
        result.extend(res)
df = pd.DataFrame(result)

在MKMapView上更新用户位置的图像

3 个答案: