Swift “我怎样才能解决问题?”;源文件中的编辑器占位符";?
问题出在这部分:Swift “我怎样才能解决问题?”;源文件中的编辑器占位符";?,swift,xcode,swiftui,Swift,Xcode,Swiftui,问题出在这部分: struct CircleView: View { var imageName: String init(_ imageName: String) { self.imageName = imageName } var body: some View { Image(imageName) .resizable() .frame(width: 100, height: 100
struct CircleView: View {
var imageName: String
init(_ imageName: String) {
self.imageName = imageName
}
var body: some View {
Image(imageName)
.resizable()
.frame(width: 100, height: 100)
.clipShape(Circle())
.overlay(
Circle().stroke(Color.gray, lineWidth: 3))
.shadow(radius: 10)
}
}
struct CircleView_Previews: PreviewProvider {
static var previews: some View {
CircleView()
}
}
XCode建议:
struct CircleView: View {
var imageName: String
init(_ imageName: String) {
self.imageName = imageName
}
var body: some View {
Image(imageName)
.resizable()
.frame(width: 100, height: 100)
.clipShape(Circle())
.overlay(
Circle().stroke(Color.gray, lineWidth: 3))
.shadow(radius: 10)
}
}
struct CircleView_Previews: PreviewProvider {
static var previews: some View {
CircleView()
}
}
调用中缺少参数#1的参数
插入“”(到CircleView()中)
在我这样做之后:
struct CircleView: View {
var imageName: String
init(_ imageName: String) {
self.imageName = imageName
}
var body: some View {
Image(imageName)
.resizable()
.frame(width: 100, height: 100)
.clipShape(Circle())
.overlay(
Circle().stroke(Color.gray, lineWidth: 3))
.shadow(radius: 10)
}
}
struct CircleView_Previews: PreviewProvider {
static var previews: some View {
CircleView()
}
}
“源文件中的编辑器占位符”出现
如何修复它?给出预期的类型,在本例中为
字符串
,该字符串对应于圆圈视图
初始化中的参数imageName
struct CircleView_Previews: PreviewProvider {
static var previews: some View {
CircleView()
}
}
结构
CircleView
具有以下初始值设定项:
struct CircleView_Previews: PreviewProvider {
static var previews: some View {
CircleView("MyImageName")
}
}
因此,在创建新的CircleView结构时,必须提供类型为String
的imageName
init(_ imageName: String) {
self.imageName = imageName
}
在将回车指向()
并单击Esc
按钮后,始终可以检查所有可用的初始值设定项及其参数名称