我实现了一个要在nav_graph中的片段之间传递的参数,但是当我尝试在原始片段中设置参数时,NavDirections找不到该参数。
请注意,在尝试传递参数之前,导航工作正常。
如果我执行“清洁项目”,则将丢失NavDirections。如果我进行重建,则会丢失参数。
Gradle:app
//Navigation
implementation "androidx.navigation:navigation-fragment-ktx:$nav_version"
implementation "androidx.navigation:navigation-ui-ktx:$nav_version"
apply plugin: "androidx.navigation.safeargs.kotlin"
nav_graph.xml
<fragment
android:id="@+id/destination_home"
android:name="com.android.joncb.flightlogbook.HomeFragment"
android:label="@string/lblHome"
tools:layout="@layout/fragment_home">
<action
android:id="@+id/action_home_to_fltHistory"
app:destination="@id/destination_fltHistory" />
<action
android:id="@+id/action_home_to_stats"
app:destination="@id/destination_statistics" />
<action
android:id="@+id/action_home_to_newFlight"
app:destination="@id/destination_newFlight" />
<action
android:id="@+id/action_home_to_fltDetails"
app:destination="@id/destination_fltDetails" />
<argument
android:name="fltData"
app:argType="string" />
</fragment>
并且在我的主片段中,出现错误“未解析的引用:fltData”
card_nextFlight.setOnClickListener {
val actionDetails = HomeFragmentDirections.actionHomeToFltDetails()
actionDetails.fltData ( flightData.toString())
Navigation.findNavController(it).navigate(actionDetails)
}
flightData是数据类
data class FlightDTO(
var airlineName: String, var faCode: String, var fltNo: String, var aircraft: String,
var depAP: String, var arrAP: String, var schedDep: String, var schedArr: String,
var date: String, var leg: Int = 0, var actDep: String = "", var actArr: String = "" ){
...
override fun toString(): String {
return "$airlineName $faCode $fltNo $aircraft $depAP $schedDep $arrAP $schedDep $date"
}
}
我想通过使类变为Parcelable来理想地传递该类,但是直到我可以传递一个字符串之前,沿着包裹线向下冒险是没有意义的。
您写的XML错误,请这样想:我构造XML属性的方式是所生成的代码在目标之间的接收方式某种...
因此基本上在nav_graph.xml中,您应该更改为:
<fragment
android:id="@+id/destination_home"
android:name="com.android.joncb.flightlogbook.HomeFragment"
android:label="@string/lblHome"
tools:layout="@layout/fragment_home">
<action
android:id="@+id/action_home_to_fltHistory"
app:destination="@id/destination_fltHistory" />
<action
android:id="@+id/action_home_to_stats"
app:destination="@id/destination_statistics" />
<action
android:id="@+id/action_home_to_newFlight"
app:destination="@id/destination_newFlight" />
<action
android:id="@+id/action_home_to_fltDetails"
app:destination="@id/destination_fltDetails">
<argument
android:name="fltData"
app:argType="string" />
</action>
</fragment>
并且在您的目的地,它应该看起来像:
<fragment
android:id="@+id/destination_fltDetails"
android:name="com.android.joncb.flightlogbook.FlightDetailsFragment"
android:label="@string/lblFlightDetails"
tools:layout="@layout/fragment_flight_details">
<argument
android:name="fltData"
app:argType="string" />
</fragment>
以及您的航班详细信息片段中的属性是通过使用:
private val args: FlightDetailsFragmentArgs by navArgs()
println(args.fltData) // prints the navigation data
UPDATE:
忘记在您的Home片段中提到OnClickListener看起来更像这样:
card_nextFlight.setOnClickListener {
val actionDetails = HomeFragmentDirections.actionHomeToFltDetails(flightData.toString())
Navigation.findNavController(it).navigate(actionDetails)
}
我没有传递数据类,而是创建了一个JSON字符串并传递了一个字符串
card_nextFlight.setOnClickListener {
val dataString = flightData.toJSONString()
val actionDetails = HomeFragmentDirections.actionHomeToFltDetails(dataString)
Navigation.findNavController(it).navigate(actionDetails)
}
要使其正常工作,我必须修改actionHomeToFltDetails函数以在HomeFragmentsDirections中接收字符串
fun actionHomeToFltDetails(fltData: String): NavDirections = ActionHomeToFltDetails(fltData)
}
我无法使用@Lucho方法来处理目标片段中的arg使其正常工作,因此恢复为捆绑管理,并将JSON字符串转换回数据类
const val ARG_PARAM1 = "fltData"
.
.
.
arguments?.let {
argFltData = it.getString(ARG_PARAM1)
Log.e("args","Passed Argument: $argFltData")
fltData = gson.fromJson(argFltData, FlightDTO::class.java)
}
再次感谢您的输入,我希望这会有助于戏剧中的其他人。