AlertDialog.Builder altBx = new AlertDialog.Builder(this);
    altBx.setTitle("My dialog box");
    altBx.setMessage("Welcome, Please Enter your name");
    altBx.setIcon(R.drawable.logo);

    altBx.setPositiveButton("Ok", new DialogInterface.OnClickListener()
    {
      public void onClick(DialogInterface dialog, int which)
      {
          if(edt.getText().toString().length()!=0)
          {
              // Show any message
          }
          else 
          {

          }
      }
    });
    altBx.setNeutralButton("Cancel", new DialogInterface.OnClickListener()
    {
      public void onClick(DialogInterface dialog, int which)
      {
          //show any message
      }

    });
  altBx.show();  

Kotlin在Android::

    override fun onBackPressed() {
        confirmToCancel()
    }

    private fun confirmToCancel() {
        AlertDialog.Builder(this)
            .setTitle("Title")
            .setMessage("Do you want to cancel?")
            .setCancelable(false)
            .setPositiveButton("Yes") {
                dialog: DialogInterface, _: Int ->
                dialog.dismiss()
                // for sending data to previous activity use
                // setResult(response code, data)
                finish()
            }
            .setNegativeButton("No") {
                dialog: DialogInterface, _: Int ->
                dialog.dismiss()
            }
            .show()
    } 

Steve H的回答是正确的，但这里有更多的信息:对话框之所以以这种方式工作，是因为Android中的对话框是异步的(当对话框显示时，执行不会停止)。因此，您必须使用回调来处理用户的选择。

在关于Android和。net的区别(因为它涉及到对话框)的更长的讨论中，看看这个问题: 对话框/ alertdialog:如何在对话框启动时“阻止执行”(. net风格)

你可以在Kotlin中轻松完成:

 alert("Testing alerts") {
    title = "Alert"
    yesButton { toast("Yess!!!") }
    noButton { }
}.show()

芬兰湾的科特林的实现。

你可以像这样创建一个简单的函数:

fun dialogYesOrNo(
        activity: Activity,
        title: String,
        message: String,
        listener: DialogInterface.OnClickListener
    ) {
        val builder = AlertDialog.Builder(activity)
        builder.setPositiveButton("Yes", DialogInterface.OnClickListener { dialog, id ->
            dialog.dismiss()
            listener.onClick(dialog, id)
        })
        builder.setNegativeButton("No", null)
        val alert = builder.create()
        alert.setTitle(title)
        alert.setMessage(message)
        alert.show()
    }

像这样叫它:

dialogYesOrNo(
  this,
  "Question",
  "Would you like to eat?",
  DialogInterface.OnClickListener { dialog, id ->
    // do whatever you need to do when user presses "Yes"
  }
})

AlertDialog.Builder altBx = new AlertDialog.Builder(this);
    altBx.setTitle("My dialog box");
    altBx.setMessage("Welcome, Please Enter your name");
    altBx.setIcon(R.drawable.logo);

    altBx.setPositiveButton("Ok", new DialogInterface.OnClickListener()
    {
      public void onClick(DialogInterface dialog, int which)
      {
          if(edt.getText().toString().length()!=0)
          {
              // Show any message
          }
          else 
          {

          }
      }
    });
    altBx.setNeutralButton("Cancel", new DialogInterface.OnClickListener()
    {
      public void onClick(DialogInterface dialog, int which)
      {
          //show any message
      }

    });
  altBx.show();