在视图存根中的按钮上设置 setOnClickListener

Question

我正在为我的登录屏幕创建一个视图存根，但是我有一个问题。当我尝试在 viewstub_login.kt 文件中的登录按钮上设置 setOnClickListener 时，按钮操作不会执行。我需要更改 Kotlin 文件的扩展名，还是需要将 setOnClickListener 放入 onStart() 函数中？谢谢！

viewstub_login.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#BF090909">

    <androidx.cardview.widget.CardView
        android:id="@+id/loginCardView"
        android:layout_width="0dp"
        android:layout_height="300dp"
        android:layout_marginStart="24dp"
        android:layout_marginEnd="24dp"
        app:cardBackgroundColor="@color/main_purple"
        app:cardCornerRadius="8dp"
        app:cardElevation="5dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <ImageView
                android:id="@+id/logoLoginImageView"
                android:layout_width="90dp"
                android:layout_height="35dp"
                android:layout_marginTop="12dp"
                android:contentDescription="@string/login_logo_image"
                android:scaleType="fitXY"
                android:src="@drawable/skedaddle_services_"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent" />

            <com.google.android.material.textfield.TextInputLayout
                android:id="@+id/emailTextInputLayout"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginStart="24dp"
                android:layout_marginTop="12dp"
                android:layout_marginEnd="24dp"
                android:textColorHint="@color/white"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/logoLoginImageView">

                <com.google.android.material.textfield.TextInputEditText
                    android:id="@+id/emailInputTextView"
                    android:layout_width="match_parent"
                    android:layout_height="48dp"
                    android:background="@drawable/textview_underlinr"
                    android:drawableStart="@drawable/outline_mail_white_24"
                    android:drawablePadding="5dp"
                    android:hint="@string/e_mail"
                    android:textColor="@color/white"
                    android:textColorHint="@color/white" />
            </com.google.android.material.textfield.TextInputLayout>

            <com.google.android.material.textfield.TextInputLayout
                android:id="@+id/passwordTextInputLayout"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginStart="24dp"
                android:layout_marginTop="12dp"
                android:layout_marginEnd="24dp"
                android:hint="@string/password"
                android:textColorHint="@color/white"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/emailTextInputLayout"
                app:passwordToggleEnabled="true"
                app:passwordToggleTint="@color/white">

                <com.google.android.material.textfield.TextInputEditText
                    android:id="@+id/passwordTextInputView"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:background="@drawable/textview_underlinr"
                    android:drawableStart="@drawable/outline_lock_white_24"
                    android:drawablePadding="5dp"
                    android:hint="@string/password"
                    android:inputType="textPassword"
                    android:textColor="@color/white"
                    android:textColorHint="@color/white" />
            </com.google.android.material.textfield.TextInputLayout>

            <Button
                android:id="@+id/forgotPasswordButton"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginStart="24dp"
                android:layout_marginEnd="24dp"
                android:background="@android:color/transparent"
                android:text="@string/forgot_password"
                android:textAlignment="textEnd"
                android:textAllCaps="false"
                android:textColor="@color/white"
                android:textSize="12sp"
                android:textStyle="italic"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/passwordTextInputLayout" />

            <Button
                android:id="@+id/cancelButton"
                android:layout_width="120dp"
                android:layout_height="48dp"
                android:background="@color/black"
                android:text="@android:string/cancel"
                android:textAllCaps="false"
                android:textColor="@color/white"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toStartOf="@+id/secondLoginButton"
                app:layout_constraintHorizontal_bias="0.5"
                app:layout_constraintHorizontal_chainStyle="packed"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/forgotPasswordButton" />

            <Button
                android:id="@+id/secondLoginButton"
                android:layout_width="120dp"
                android:layout_height="48dp"
                android:layout_marginStart="32dp"
                android:background="@color/main_teal"
                android:text="@string/log_in"
                android:textAllCaps="false"
                android:textColor="#FFFFFF"
                app:layout_constraintBottom_toBottomOf="@+id/cancelButton"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintHorizontal_bias="0.5"
                app:layout_constraintStart_toEndOf="@+id/cancelButton"
                app:layout_constraintTop_toTopOf="@+id/cancelButton"
                tools:ignore="TextContrastCheck" />

        </androidx.constraintlayout.widget.ConstraintLayout>
    </androidx.cardview.widget.CardView>
</androidx.constraintlayout.widget.ConstraintLayout>

viewstub_login.kt

class LoginViewStub : AppCompatActivity() {

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

        val emailTextView = findViewById<TextInputEditText>(R.id.emailInputTextView)
        val passwordTextView = findViewById<TextInputEditText>(R.id.passwordTextInputView)
        val forgetPasswordButton = findViewById<Button>(R.id.forgotPasswordButton)
        val loginButton = findViewById<Button>(R.id.secondLoginButton)
        val cancelButton = findViewById<Button>(R.id.cancelButton)

        val emailText = emailTextView.text
        val passwordText = passwordTextView.text

        loginButton.setOnClickListener {
            if (emailText.isEmpty(emailTextView.text) || passwordText.isEmpty(passwordTextView.text)) {
                val dialogBuilder = AlertDialog.Builder(this)
                dialogBuilder.setMessage("Please fill out all fields.").setCancelable(false).setPositiveButton("Okay", DialogInterface.OnClickListener {
                    dialog, id -> finish()
                }).setNegativeButton("Cancel", DialogInterface.OnClickListener {
                    dialog, id -> dialog.cancel()
                })

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

        cancelButton.setOnClickListener {

        }

        forgetPasswordButton.setOnClickListener {

        }
    }

}

private fun Boolean.isEmpty(str: CharSequence?): Boolean {
    return str == null || str.length == 0
}

Answer 1

点击侦听器是正确的，但在块内部，您的代码不正确因为 emailText 和 passwordText 不为空，正如您在上面定义的那样，因此 if 条件返回 false 并且您的代码只是通过它

在视图存根中的按钮上设置 setOnClickListener

Setting setOnClickListener on a Button in a View Stub

android

viewstub

android-button

kotlin