android - Kotlin中使用AlertDialog输入错误密码时如何返回输入界面？

Question

我希望在启动APP时能打开一个密码输入对话框。

如果我输入正确的密码，对话框将关闭并显示主 UI。

如果我输入错误密码，对话框将保持打开状态并要求用户再次输入。

我该怎么做？谢谢!

目前无论密码输入正确还是错误，对话框都是关闭的。

  override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.layout_main)      
        showInputPasswordDialog()
    }  


    private fun showInputPasswordDialog {    
        val editText = EditText(this)
        val inputDialog = AlertDialog.Builder(this)
        inputDialog.setTitle("Input")
                   .setView(editText)
                   .setCancelable(false)
                   .setNegativeButton("Cancel", DialogInterface.OnClickListener { dialog, which ->
                           finish();
                   })

        inputDialog.setPositiveButton("OK",
                DialogInterface.OnClickListener { dialog, which ->
                    val password= editText.text.toString()
                    if (password=="aa"){
                        //close the dialog
                    }else{
                        toast("Password error")
                        //Return for input again
                    }
                }).show()
    }

Answer 1

如果您在 alertDialog.onShowlistener 中处理正按钮的 onclick 监听器，那么您可以避免对话框关闭流程。请在下面找到修改后的代码。

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.layout_main)      
        showInputPasswordDialog()
    }  


    private fun showInputPasswordDialog {    
        val editText = EditText(this)
        val inputDialog = AlertDialog.Builder(this)
        inputDialog.setTitle("Input")
                   .setView(editText)
                   .setCancelable(false)
                   .setNegativeButton("Cancel", DialogInterface.OnClickListener { dialog, which ->
                           finish();
                   })

        inputDialog.setPositiveButton("OK",null)

       // modified code starts here
        val mAlertDialog = inputDialog.create()

        mAlertDialog.setOnShowListener(DialogInterface.OnShowListener {
        val b = mAlertDialog.getButton(AlertDialog.BUTTON_POSITIVE)
        b.setOnClickListener(View.OnClickListener {

          val password= editText.text.toString()
                if (password=="aa"){
                    mAlertDialog.dismiss();
                    //close the dialog
                }else{
                    toast("Password error")
                    //Return for input again
                }

        })
    })

    mAlertDialog.show() 

    }

引用:How to prevent a dialog from closing when a button is clicked