Question

我想根据路线方向旋转标记图像。我使用Map box SDK实现了地图。坐标＆amp;方向是通过webservice获取的。我试过imageForMarker，但它没有用。实施如下

func mapView(_ mapView: MGLMapView, imageFor annotation: MGLAnnotation) -> MGLAnnotationImage? {

    let img = imageRotatedByDegrees(oldImage: UIImage(named: "car")!, deg: CGFloat(self.bearing))

    return MGLAnnotationImage(image: img, reuseIdentifier: "car")
}
func imageRotatedByDegrees(oldImage: UIImage, deg degrees: CGFloat) -> UIImage
{
    let size = oldImage.size

    UIGraphicsBeginImageContext(size)

    let bitmap: CGContext = UIGraphicsGetCurrentContext()!
    //Move the origin to the middle of the image so we will rotate and scale around the center.
    bitmap.translateBy(x: size.width / 2, y: size.height / 2)
    //Rotate the image context
    bitmap.rotate(by: (degrees * CGFloat(Double.pi / 180)))
    //Now, draw the rotated/scaled image into the context
    bitmap.scaleBy(x: 1.0, y: -1.0)

    let origin = CGPoint(x: -size.width / 2, y: -size.width / 2)

    bitmap.draw(oldImage.cgImage!, in: CGRect(origin: origin, size: size))

    let newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()
    return newImage
}

Answer 1

尝试使用自定义重用标识符，如下所示：

import tensorflow as tf
sess = tf.InteractiveSession()
text0 = """/a/b/c_d/f_g_h_2017"""
text1 = """/a/b/c\_d/f\_g\_h\_2017"""
text2 = """/a/b/c\\_d/f\\_g\\_h\\_2017"""

summary_op0 = tf.summary.text('text', tf.convert_to_tensor(text0))
summary_op1 = tf.summary.text('text', tf.convert_to_tensor(text1))
summary_op2 = tf.summary.text('text', tf.convert_to_tensor(text2))
summary_op = tf.summary.merge([summary_op0, summary_op1, summary_op2])
summary_writer = tf.summary.FileWriter('/tmp/tensorboard', sess.graph)
summary = sess.run(summary_op)
summary_writer.add_summary(summary, 0)
summary_writer.flush()
summary_writer.close()

Answer 2

看来正确的方法是使用带注释的MGLSymbolStyleLayer，而不是直接添加注释并使用mapview委托方法：https://www.mapbox.com/ios-sdk/api/3.6.2/Classes/MGLSymbolStyleLayer.html#/c:objc(cs)MGLSymbolStyleLayer(py)iconRotation

您可以使用iconRotation属性，该属性取得度数。

这很不幸，因为我的用例有几个相同的图像但是标题不同，所以我必须为每个图像添加一个图层。

如何在Mapbox 3.6中旋转汽车标记图像？

2 个答案: