如何通过不同按钮结合提交按钮打开对应Fragment？

没问题，这个需求实现起来很清晰，我给你一步步拆解实现思路和代码示例，保证能快速搞定：

我们需要一个变量来记录用户之前点击的是Button 1还是Button 2，然后在点击Submit按钮时，根据这个变量的值来决定加载哪个Fragment。同时可以给选中的按钮加个视觉反馈，让用户清楚自己的选择。

1. 编写Activity布局 #

首先在你的Activity布局里添加三个按钮和一个Fragment容器（用来承载后续的Fragment）：

<!-- activity_main.xml -->
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp">

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button 1"/>

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button 2"/>

    <Button
        android:id="@+id/buttonSubmit"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Submit"/>

    <!-- Fragment容器，用来显示Fragment1或Fragment2 -->
    <FrameLayout
        android:id="@+id/fragmentContainer"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"/>
</LinearLayout>

2. 实现Activity逻辑（Kotlin版本） #

在你的Activity中定义变量记录选中状态，处理按钮点击事件，并封装Fragment切换方法：

class MainActivity : AppCompatActivity() {
    // 记录用户选中的按钮，null表示未选择
    private var selectedButton: Int? = null

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

        // Button 1点击事件：标记选中状态+视觉反馈
        button1.setOnClickListener {
            selectedButton = 1
            updateButtonSelectionUI(true, false)
        }

        // Button 2点击事件：标记选中状态+视觉反馈
        button2.setOnClickListener {
            selectedButton = 2
            updateButtonSelectionUI(false, true)
        }

        // Submit按钮点击事件：根据选中状态加载对应Fragment
        buttonSubmit.setOnClickListener {
            when(selectedButton) {
                1 -> loadTargetFragment(Fragment1())
                2 -> loadTargetFragment(Fragment2())
                else -> {
                    // 未选择时提示用户
                    Toast.makeText(this, "请先选择Button 1或Button 2哦", Toast.LENGTH_SHORT).show()
                }
            }
        }
    }

    // 更新按钮选中状态的UI
    private fun updateButtonSelectionUI(isButton1Selected: Boolean, isButton2Selected: Boolean) {
        val selectedColor = ContextCompat.getColor(this, R.color.selected_button)
        val defaultColor = ContextCompat.getColor(this, R.color.default_button)
        
        button1.setBackgroundColor(if (isButton1Selected) selectedColor else defaultColor)
        button2.setBackgroundColor(if (isButton2Selected) selectedColor else defaultColor)
    }

    // 封装Fragment切换方法
    private fun loadTargetFragment(fragment: Fragment) {
        supportFragmentManager.beginTransaction()
            .replace(R.id.fragmentContainer, fragment)
            .commit()
    }

    // 保存屏幕旋转等状态变化时的选中状态
    override fun onSaveInstanceState(outState: Bundle) {
        super.onSaveInstanceState(outState)
        outState.putInt("selectedButton", selectedButton ?: -1)
    }

    // 恢复状态
    override fun onRestoreInstanceState(savedInstanceState: Bundle) {
        super.onRestoreInstanceState(savedInstanceState)
        val savedValue = savedInstanceState.getInt("selectedButton")
        selectedButton = if (savedValue != -1) savedValue else null
        // 恢复UI状态
        updateButtonSelectionUI(selectedButton == 1, selectedButton == 2)
    }
}

3. 创建Fragment类 #

创建Fragment1和Fragment2的基础类，比如：

// Fragment1.kt
class Fragment1 : Fragment() {
    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        return inflater.inflate(R.layout.fragment1, container, false)
    }
}

// Fragment2.kt
class Fragment2 : Fragment() {
    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        return inflater.inflate(R.layout.fragment2, container, false)
    }
}

对应的fragment1.xml和fragment2.xml可以根据你的需求编写布局内容。

4. Java版本参考 #

如果用Java开发，核心逻辑完全一致，只是语法不同：

public class MainActivity extends AppCompatActivity {
    private Integer selectedButton = null;

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

        Button button1 = findViewById(R.id.button1);
        Button button2 = findViewById(R.id.button2);
        Button buttonSubmit = findViewById(R.id.buttonSubmit);

        button1.setOnClickListener(v -> {
            selectedButton = 1;
            updateButtonSelectionUI(true, false);
        });

        button2.setOnClickListener(v -> {
            selectedButton = 2;
            updateButtonSelectionUI(false, true);
        });

        buttonSubmit.setOnClickListener(v -> {
            if (selectedButton == 1) {
                loadTargetFragment(new Fragment1());
            } else if (selectedButton == 2) {
                loadTargetFragment(new Fragment2());
            } else {
                Toast.makeText(MainActivity.this, "请先选择Button 1或Button 2", Toast.LENGTH_SHORT).show();
            }
        });
    }

    private void updateButtonSelectionUI(boolean isButton1Selected, boolean isButton2Selected) {
        int selectedColor = ContextCompat.getColor(this, R.color.selected_button);
        int defaultColor = ContextCompat.getColor(this, R.color.default_button);
        
        findViewById(R.id.button1).setBackgroundColor(isButton1Selected ? selectedColor : defaultColor);
        findViewById(R.id.button2).setBackgroundColor(isButton2Selected ? selectedColor : defaultColor);
    }

    private void loadTargetFragment(Fragment fragment) {
        getSupportFragmentManager().beginTransaction()
                .replace(R.id.fragmentContainer, fragment)
                .commit();
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt("selectedButton", selectedButton != null ? selectedButton : -1);
    }

    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);
        int savedValue = savedInstanceState.getInt("selectedButton");
        selectedButton = savedValue != -1 ? savedValue : null;
        updateButtonSelectionUI(selectedButton == 1, selectedButton == 2);
    }
}

• 记得在colors.xml里定义selected_button和default_button的颜色值，比如：

<color name="selected_button">#2196F3</color>
<color name="default_button">#E0E0E0</color>

• 如果需要添加Fragment的切换动画，可以在beginTransaction()后调用setCustomAnimations()方法实现。

内容的提问来源于stack exchange，提问作者Shiva