在检查并尝试实施至少8种不同的建议解决方案以在android studio 3.2.1中显示消息框/对话框/警报后，我注意到我无法找到以下任一建议的解决方案：
如何在GateKeeper.kt中显示字符串accountType的值？
这总结了我到目前为止的尝试：
package com.greyblocks.gatekeeper
import android.accounts.Account
import android.accounts.AccountManager
import android.app.Activity
import android.app.AlertDialog
import android.content.DialogInterface
import android.graphics.Color
import android.os.Build
import android.os.Bundle
import android.view.View
import android.widget.TextView
import android.widget.Toast
import java.io.File
import java.io.PrintWriter
import com.google.android.material.snackbar.Snackbar
//import android.support.design
//import com.greyblocks.gatekeepersample.MainActivity
import android.widget.AdapterView
import android.content.ContextWrapper
import android.widget.EditText
import android.util.Log
import com.google.android.material.R.id.title
import com.greyblocks.gatekeeper.R.id.info
@Suppress("unused")
open class GateKeeper(private val accountManager: AccountManager,
private val accountType: String) {
fun getCurrentAccount(): Account? {
val accounts = accountManager.getAccountsByType(accountType)
if (accounts.isNotEmpty()) {
return accounts[0]
}
return null
}
fun getAuthToken(): String? {
val account = getCurrentAccount()
return account?.let { accountManager.peekAuthToken(getCurrentAccount(), AccountAuthenticator.AUTHTOKEN_TYPE_FULL_ACCESS) }
}
fun enter(user: String, password: String?, authToken: String, userData: Bundle? = null) {
if (getCurrentAccount() != null) {
logout()
}
accountManager.addAccountExplicitly(Account(user, accountType), password, userData)
accountManager.setAuthToken(getCurrentAccount(), AccountAuthenticator.AUTHTOKEN_TYPE_FULL_ACCESS, authToken)
}
fun saveUserData(key: String, value: Long) {
accountManager.setUserData(getCurrentAccount(), key, value.toString())
}
fun saveUserData(key: String, value: Int) {
accountManager.setUserData(getCurrentAccount(), key, value.toString())
}
fun saveUserData(key: String, value: String) {
accountManager.setUserData(getCurrentAccount(), key, value)
}
fun getUserData(key: String, defaultData: String? = null): String? {
return accountManager.getUserData(getCurrentAccount(), key) ?: defaultData
}
fun getLong(key: String): Long {
return accountManager.getUserData(getCurrentAccount(), key)?.toLongOrNull() ?: 0L
}
fun getInt(key: String): Int {
return accountManager.getUserData(getCurrentAccount(), key)?.toIntOrNull() ?: 0
}
fun logout() {
//try to write something to screen:
print("Maximum of a or b is " );
Log.d("TAG", "message")
println("other message")
//info("London is the capital of Great Britain")
// debug(5) // .toString() method will be executed
// warn(null) // "null" will be printed
// toast("Hello, ${name.text}!")
fun print(message: Any?) {}
var message:String
message="D";
fun print(message: String) {}
//try to write something to file:
//writeToTxt(accountType); Crashes upon pressing logout
if (getCurrentAccount() != null) {
accountManager.invalidateAuthToken(accountType, getAuthToken())
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP_MR1) {
accountManager.removeAccountExplicitly(getCurrentAccount())
} else {
@Suppress("DEPRECATION")
accountManager.removeAccount(getCurrentAccount(), null, null)
}
}
}
@Suppress("MemberVisibilityCanBePrivate")
fun isLoggedIn(): Boolean {
return getAuthToken() != null
}
fun checkUserAuth(activity: Activity) {
if (!isLoggedIn()) {
accountManager.addAccount(accountType, AccountAuthenticator.AUTHTOKEN_TYPE_FULL_ACCESS, null, null, activity,
null, null)
activity.finish()
}
}
//Attempt 0: Can't find an import for alert
// fun messageBox(String inputString){
// alert("Testing alerts") {
// title = "Alert"
// yesButton { toast("Yess!!!") }
// noButton { }
// }.show()
// }
//Attempt 1: Problem: needs to be called from an object "this" which does not exist in this file.
// fun showNormalAlert(v: View){
// val dialog = AlertDialog.Builder(this).setTitle("Kotlin Study").setMessage("Alert Dialog")
// .setPositiveButton("Confirm", { dialog, i ->
// val applicationContext=null;
// Toast.makeText(applicationContext, "Hello Friends", Toast.LENGTH_LONG).show()
// })
// .setNegativeButton("Cancel", { dialog, i -> })
// dialog.show()
// }
//Attempt 2: Can't find somefile.txt
// fun writeToTxt(input: String) {
// File("somefile.txt").printWriter().use { out ->
// out.println("${input}, ${"text1"}")
//
// }
// }
//Attempt 3: can't find file.txt
fun writeToTxt(input: String) {
PrintWriter("file.txt").use {
for (i in 1..5) {
println(i)
}
}
}
//Attempt 4: Do not know yet how to create a parentview in the middle of this code
// fun writeToTxt(input: String) {
// Snackbar.make(parentView, "The string = ", Snackbar.LENGTH_LONG).show()
// }
//Attempt 5: Don't yet know how to import the design
// fun onSNACK(view: View){
// //Snackbar(view)
// val snackbar = Snackbar.make(view, "Replace with your own action",
// Snackbar.LENGTH_LONG).setAction("Action", null)
// snackbar.setActionTextColor(Color.BLUE)
// val snackbarView = snackbar.view
// snackbarView.setBackgroundColor(Color.LTGRAY)
// val textView =
// snackbarView.findViewById(android.support.design.R.id.snackbar_text) as TextView
// textView.setTextColor(Color.BLUE)
// textView.textSize = 28f
// snackbar.show()
// }
//Attempt 6: Don't yet know how to generate the AdapterView<*>
// fun showPopup(parent: AdapterView<*>, view: View,
// position: Int, rowId: Long) {
// val result: String;
// val context = ContextWrapper(null)
// val dialog = AlertDialog.Builder(ContextWrapper(null)).show()
// val adb = AlertDialog.Builder(context)
//
// adb.setTitle("List")
// adb.setMessage(" selected Item is=" + parent.getItemAtPosition(position))
// adb.setPositiveButton("Ok", null)
// adb.show()
// Snackbar.make(view, "Invalid username or password", Snackbar.LENGTH_LONG).show()
// }
//Attempt 7: Crashes App upon opening
// @Throws(Exception::class)
// fun shouldSetView() {
// val context = ContextWrapper(null)
// val builder = AlertDialog.Builder(context)
// val view = EditText(context)
// builder.setView(view)
//
// val alert = builder.create()
// //shadowOf(alert).getView()
// view as View
// }
//Attempt 8: Can't import inflate
// fun showNewNameDialog() {
// val dialogBuilder = AlertDialog.Builder(this)
// val inflater = this.layoutInflater
// val dialogView = inflater.inflate(R.layout.custom_dialog, null)
// dialogBuilder.setView(dialogView)
//
// val editText = dialogView.findViewById<View>(R.id.editTextName) as EditText
//
// dialogBuilder.setTitle("Custom dialog")
// dialogBuilder.setMessage("Enter Name Below")
// dialogBuilder.setPositiveButton("Save", { dialog, whichButton ->
// //do something with edt.getText().toString();
//
// // Add Name in list
// nameList.add(editText.text.toString())
// // Handler code here.
// val intent = Intent(this, NewKitListActivity::class.java)
// startActivity(intent);
//
// })
// dialogBuilder.setNegativeButton("Cancel", { dialog, whichButton ->
// //pass
// })
// val b = dialogBuilder.create()
// b.show()
// }
}
出于完整性考虑：我在MainActivity中找到了gatekeepersample/java/com.greyblocks.gatekeepersample/MainActivity.kt。我已经能够在gatekeeper/res/layout/activity_main.xml的布局中添加一个按钮，并且在该按钮内部，我可以显示警报对话框。但是，我的问题仍然是如何在MainActivity外部显示警报对话框而不修改布局。评论建议通过“服务”来做到这一点。我正在调查。