点击按钮跳转新布局显示ListView时应用崩溃问题求助

你的应用崩溃核心原因是布局文件与Activity的绑定完全搞反，导致代码中找不到目标控件触发空指针异常，和Android Studio配置无关。以下是具体问题点和修正方案：

问题点 #

1. MainActivity绑定了activity_main.xml，但该布局仅包含ListView，无按钮控件，代码中findViewById(R.id.button)会返回null，触发空指针
2. ListViewActivity绑定了activity_listview.xml，但该布局仅包含按钮，无ListView控件，代码中findViewById(R.id.listView)返回null，调用setAdapter时直接崩溃
3. MainActivity中findViewById(R.id.main)同样会空指针，因为原activity_main.xml没有该ID的布局容器

修正后的代码 #

1. 修正MainActivity对应的布局 activity_main.xml #

该布局需包含触发跳转的按钮：

<?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:id="@+id/main"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="显示列表"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:layout_marginTop="26dp"/>

</androidx.constraintlayout.widget.ConstraintLayout>

2. 修正ListViewActivity对应的布局 activity_listview.xml #

该布局需包含显示列表的ListView：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</RelativeLayout>

3. 确认MainActivity代码（无需修改，布局修正后即可正常运行） #

package fr.yodrack.simplelistview;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
            Insets systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom);
            return insets;
        });

        Button button = findViewById(R.id.button);
        button.setOnClickListener(v -> {
            Intent intent = new Intent(MainActivity.this, ListViewActivity.class);
            startActivity(intent);
        });
    }
}

4. 确认ListViewActivity代码（无需修改，布局修正后即可正常运行） #

package fr.yodrack.simplelistview;

import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import androidx.appcompat.app.AppCompatActivity;
import java.util.ArrayList;

public class ListViewActivity extends AppCompatActivity {

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

        ArrayList<String> dataList = new ArrayList<>();
        dataList.add("Élément 1");
        dataList.add("Élément 2");
        dataList.add("Élément 3");

        ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, dataList);

        ListView listView = findViewById(R.id.listView);
        listView.setAdapter(adapter);
    }
}

5. 检查AndroidManifest.xml #

确保已注册ListViewActivity：

<activity
    android:name=".ListViewActivity"
    android:exported="false" />

内容的提问来源于stack exchange，提问作者yodrack