Question

以下是MainActivity onCreate方法中的AlertDialog：

import kotlinx.android.synthetic.main.dialog.*

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        fab.setOnClickListener { view ->
            AlertDialog.Builder(this@MainActivity)
                    .setView(LayoutInflater.from(this@MainActivity).inflate(R.layout.dialog, null))
                    .setPositiveButton("OK") {dialog, i ->
                        Toast.makeText(
                                this@MainActivity, dialogEditText.text, Toast.LENGTH_SHORT)
                                .show()
                        dialog.dismiss()
                    }.show()
        }
    }
}

这是对话框布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <EditText
        android:id="@+id/dialogEditText"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">
    </EditText>
</RelativeLayout>

然而，最后，我收到了这个错误：

java.lang.IllegalStateException：dialogEditText不能为null

但我填写了输入......这里有什么问题？

Answer 1

这是我找到的解决方案。谢谢你的帮助！

    val view = LayoutInflater.from(this@MainActivity).inflate(R.layout.dialog, null)
    AlertDialog.Builder(this@MainActivity)
            .setView(view)
            .setPositiveButton("OK") {dialog, i ->
                Toast.makeText(
                        this@MainActivity, view.dialogEditText.text, Toast.LENGTH_SHORT)
                        .show()
                dialog.dismiss()
            }.show()

Answer 2

 import kotlinx.android.synthetic.main.dialog.*
    val dialogBuilder = AlertDialog.Builder(this)
        val inflater = this.layoutInflater
        val dialogView = inflater.inflate(R.layout.dialog, null)
        dialogBuilder.setView(dialogView)
        val editText = dialogView.findViewById<View>(R.id.dialogEditText) as EditText
        dialogBuilder.setTitle("Your Dialog")
        dialogBuilder.setPositiveButton("OK", DialogInterface.OnClickListener { dialog, whichButton ->
           Toast.makeText(this@MainActivity, editText.text.toString(), Toast.LENGTH_SHORT)
                                    .show() 
                                     dialog.dismiss()

        })
        val b = dialogBuilder.create()
        b.show()

为什么从自定义对话框EditText返回null？

2 个答案: