Android Studio Firebase 应用程序错误？

Question

按照有关 android 开发的教程，我遇到了错误，当我尝试创建 EditTextTitle 和 EditTextDescription 变量时遇到了几个错误。 此外，当我尝试在 saveNote 方法中传递 (View v) 参数时，会出现相同的错误，下面是我的 XML 文件和 Java 主代码：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
    android:padding="16dp"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/edit_text_title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Title"
        android:inputType="text"/>

    <EditText
        android:id="@+id/edit_text_description"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="Description"
        android:inputType="text"/>

    <button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Save"
        android:onClick="saveNote"/>


</LinearLayout>

主要活动：

package com.example.firestoreapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

import com.google.firebase.firestore.FirebaseFirestore;

public class MainActivity extends AppCompatActivity {
    //constants, variables that cannot change essentially
    //logt shortcut
    private static final String TAG = "MainActivity";
    //title
    //description
    private static final String KEY_TITLE = "title";
    private static final String KEY_DESCRIPTION = "description";

    //idk why this is not working
    private EditText editTextTitle;
    private EditText editTextDescription;

    //reference for firebase database
    private FirebaseFirestore db = FirebaseFirestore.getInstance();


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //
        editTextTitle = findViewById(R.id.edit_text_title);
        editTextDescription = findViewById(R.id.edit_text_description);
    }

    public void saveNote (View v) {
        String title = editTextTitle.getText().toString();
        String description = editTextDescription.getText().toString();
    }

}

Answer 1

您的布局中的button元素标签应更改为Button ，如下所示。

<Button
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="Save"
    android:onClick="saveNote"/>