我在Xamarin Forms项目中创建了一个Android工具栏：
extension ViewController{
//------------------------------------------------
//MARK: Get CIImageProperyOrientation From UIImage
//------------------------------------------------
/// Converts A UIImageOrientation To A CGImagePropertyOrientation
///
/// - Parameter orientation: UIImageOrientation
/// - Returns: CGImagePropertyOrientation
func cgImagePropertyOrientation(_ orientation: UIImageOrientation) -> CGImagePropertyOrientation {
switch orientation {
case .up:
return .up
case .upMirrored:
return .upMirrored
case .down:
return .down
case .downMirrored:
return .downMirrored
case .leftMirrored:
return .leftMirrored
case .right:
return .right
case .rightMirrored:
return .rightMirrored
case .left:
return .left
}
}
//---------------------
//MARK: File Management
//---------------------
/// Returns The Documents Directory
///
/// - Returns: URL
func getDocumentsDirectory() -> URL {
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
let documentsDirectory = paths[0]
return documentsDirectory
}
}
extension ViewController: ARSCNViewDelegate{
func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
//1. If Out Target Image Has Been Detected Than Get The Corresponding Anchor
guard let currentImageAnchor = anchor as? ARImageAnchor else { return }
//2. Get The Targets Name
let name = currentImageAnchor.referenceImage.name!
//3. Get The Targets Width & Height
let width = currentImageAnchor.referenceImage.physicalSize.width
let height = currentImageAnchor.referenceImage.physicalSize.height
//4. Log The Reference Images Information
print("""
Image Name = \(name)
Image Width = \(width)
Image Height = \(height)
""")
//5. Create A Plane Geometry To Cover The ARImageAnchor
let planeNode = SCNNode()
let planeGeometry = SCNPlane(width: width, height: height)
planeGeometry.firstMaterial?.diffuse.contents = UIColor.white
planeNode.opacity = 0.25
planeNode.geometry = planeGeometry
//6. Rotate The PlaneNode To Horizontal
planeNode.eulerAngles.x = -.pi/2
//7. The Node Is Centered In The Anchor (0,0,0)
node.addChildNode(planeNode)
//8. Create AN SCNBox
let boxNode = SCNNode()
let boxGeometry = SCNBox(width: 0.1, height: 0.1, length: 0.1, chamferRadius: 0)
//9. Create A Different Colour For Each Face
let faceColours = [UIColor.red, UIColor.green, UIColor.blue, UIColor.cyan, UIColor.yellow, UIColor.gray]
var faceMaterials = [SCNMaterial]()
//10. Apply It To Each Face
for face in 0 ..< 5{
let material = SCNMaterial()
material.diffuse.contents = faceColours[face]
faceMaterials.append(material)
}
boxGeometry.materials = faceMaterials
boxNode.geometry = boxGeometry
//11. Set The Boxes Position To Be Placed On The Plane (node.x + box.height)
boxNode.position = SCNVector3(0 , 0.05, 0)
//12. Add The Box To The Node
node.addChildNode(boxNode)
}
}
class ViewController: UIViewController {
//1. Create A Reference To Our ARSCNView In Our Storyboard Which Displays The Camera Feed
@IBOutlet weak var augmentedRealityView: ARSCNView!
//2. Create Our ARWorld Tracking Configuration
let configuration = ARWorldTrackingConfiguration()
//3. Create Our Session
let augmentedRealitySession = ARSession()
//4. Create An Array To Store Our Reference Images
var customReferenceImages = [ARReferenceImage]()
//5. Create An Identifier So We Can Create A Unique Name For Each Image
var identifier = 0
//--------------------
//MARK: View LifeCycle
//--------------------
override func viewDidLoad() {
setupARSession()
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
//--------------------------------
//MARK: Creation Of Dynamic Images
//--------------------------------
/// Saves The Snapshot Of An ARSCNView
@IBAction func saveScreenShot(){
//1. Create A Snapshot Of The ARView
let screenShot = self.augmentedRealityView.snapshot()
//2. Convert It To A PNG
guard let imageData = UIImagePNGRepresentation(screenShot) else { return }
//3. Store The File In The Documents Directory
let fileURL = getDocumentsDirectory().appendingPathComponent("custom\(identifier).png")
//4. Write It To The Documents Directory & Increase The Identifier
do {
try imageData.write(to: fileURL)
identifier += 1
} catch {
print("Error Saving File")
}
//5. Load The Custom Images
loadCustomImages()
}
/// Loads Any Custom Images From The Documents Directory & Appends Them To A Custom [ARReferenceImage]
func loadCustomImages(){
//1. Get Reference To The NSFileManager
let fileManager = FileManager.default
//2. Get The URL Of The Documents Directory
let documentsDirectory = getDocumentsDirectory()
do {
//a. Get All Files In The Documents Directory
let fileURLs = try fileManager.contentsOfDirectory(at: documentsDirectory, includingPropertiesForKeys: nil)
//b. Loop Through Them And If The Path Contains Our Custom Prefix Then Convert To CGImage & Then ARReference Image
for file in fileURLs{
if file.lastPathComponent.hasPrefix("custom"){
if let arImage = UIImage(contentsOfFile: file.path), let arCGImage = arImage.cgImage{
/* Here You Will Need To Work Out The Pysical Widht Of The Image In Metres */
let widthInCM: CGFloat = CGFloat(arCGImage.width) / CGFloat(47)
let widthInMetres: CGFloat = widthInCM * 0.01
let arReferenceImage = ARReferenceImage(arCGImage,
orientation: cgImagePropertyOrientation(arImage.imageOrientation),
physicalWidth: widthInMetres)
arReferenceImage.name = file.lastPathComponent
customReferenceImages.append(arReferenceImage)
}
}
}
} catch {
print("Error Listing Files \(documentsDirectory.path): \(error.localizedDescription)")
}
//3. Set Our ARSession Configuration Detection Images
configuration.detectionImages = Set(customReferenceImages)
augmentedRealitySession.run(configuration, options: [.resetTracking, .removeExistingAnchors ])
}
//---------------
//MARK: ARSession
//---------------
/// Sets Up The ARSession
func setupARSession(){
//1. Set The AR Session
augmentedRealityView.session = augmentedRealitySession
//2. Conifgure The Type Of Plane Detection
configuration.planeDetection = []
//3. If In Debug Mode Show Statistics
#if DEBUG
augmentedRealityView.showsStatistics = true
#endif
//4. Run The Session
augmentedRealitySession.run(configuration, options: [.resetTracking, .removeExistingAnchors])
augmentedRealityView.delegate = self
}
}
通过执行以下操作，我可以轻松设置背景颜色和其他布局参数：
var toolbar = activity.LayoutInflater
.Inflate(FormsAppCompatActivity.ToolbarResource, null)
.JavaCast<Android.Support.V7.Widget.Toolbar>();
然而，我无法想出以编程方式设置字体大小的方法，因为设置它的方法是：
toolbar.LayoutParameters = new LayoutParams(LayoutParams.MatchParent, LayoutParams.WrapContent);
toolbar.SetBackgroundColor(backgroundColor.ToAndroid());
我不想用配置的资源设置它。我想用字体大小和/或其他样式属性动态设置它。我怎么能这样做？
答案 0 :(得分：0)
我不知道使用java是否是同样的事情。当我遇到这个问题时，我在我的 java 代码中添加了一个setSupportActionBar(toolbar);。结果是这样的：
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle(loggedUserName);
setSupportActionBar(toolbar);
工作得很好。