feat: 上传第三次安卓课程代码(2026年10月09日)

app/src/main/java/com/yanzitong/activitytest6117/FirstActivity.java

@@ -1,16 +1,20 @@
 package com.yanzitong.activitytest6117;
 
+import android.content.Intent;
 import android.os.Bundle;
 import android.util.Log;
+import android.view.ContextMenu;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.widget.Button;
+import android.widget.LinearLayout;
 import android.widget.Toast;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
+import androidx.appcompat.widget.PopupMenu;
 
 // 组合键：shift + enter
 public class FirstActivity extends AppCompatActivity {
@@ -20,6 +24,9 @@ public class FirstActivity extends AppCompatActivity {
     // 全局（成员）变量：m开头
     Button mFirstBtn1;
     Button mFirstBtn2;
+    LinearLayout mFirstLinearLayout;
+    Button mFirstBtn3;
+    Button mFirstBtn4;
 
     /**
      * 事件驱动机制
@@ -33,13 +40,40 @@ public class FirstActivity extends AppCompatActivity {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.first_layout);
         Log.d(TAG, "onCreate: 活动创建成功"); // 组合键2：alter + enter
+
+        mFirstBtn4 = findViewById(R.id.first_btn4);
+        mFirstBtn4.setOnClickListener(v -> {
+            // Activity之间的跳转——显式Intent
+            Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
+            startActivity(intent);
+        });
+
+        mFirstBtn3 = findViewById(R.id.first_btn3);
+        mFirstBtn3.setOnClickListener(v -> {
+            finish();
+        });
+
         mFirstBtn1 = findViewById(R.id.first_btn1);
         mFirstBtn1.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
                 Toast.makeText(FirstActivity.this, "6117严梓桐单击了按钮", Toast.LENGTH_SHORT).show();
+                PopupMenu popupMenu = new PopupMenu(FirstActivity.this, v);     // this, super
+                popupMenu.getMenuInflater().inflate(R.menu.main, popupMenu.getMenu());
+                popupMenu.setOnMenuItemClickListener(item -> {
+                    if (item.getItemId() == R.id.add_item) {
+                        Toast.makeText(FirstActivity.this, "单击了add按钮", Toast.LENGTH_SHORT).show();
+                    } else if (item.getItemId() == R.id.modify_item) {
+                        Toast.makeText(FirstActivity.this, "单击了modify按钮", Toast.LENGTH_SHORT).show();
+                    } else if (item.getItemId() == R.id.delete_item) {
+                        Toast.makeText(FirstActivity.this, "单击了delete按钮", Toast.LENGTH_SHORT).show();
+                    }
+                    return true;
+                });     // 箭头函数（lambda表达式）——接口[只能有一个抽象函数]
+                popupMenu.show();
             }
         });
+
         mFirstBtn2 = findViewById(R.id.first_btn2);
         mFirstBtn2.setOnClickListener(new View.OnClickListener() {
             @Override
@@ -48,8 +82,43 @@ public class FirstActivity extends AppCompatActivity {
                 Toast.makeText(FirstActivity.this, "我是严梓桐", Toast.LENGTH_SHORT).show();
             }
         });
+
+        mFirstLinearLayout = findViewById(R.id.first_linear_layout);
+        registerForContextMenu(mFirstLinearLayout);
     }
 
+    // 弹出式菜单——触发事件
+
+
+    // 上下文菜单
+    // ctrl + shift + "+ / -": 展开、折叠代码块
+    @Override
+    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
+        super.onCreateContextMenu(menu, v, menuInfo);
+        menu.setHeaderTitle("上下文菜单");
+        // 参数1：分组号，参数2：item编号，参数3：顺序编号
+        menu.add(1, 1, 1, "保存");
+        menu.add(1, 2, 2, "更改");
+        menu.add(1, 3, 3, "删除");
+    }
+
+    @Override
+    public boolean onContextItemSelected(@NonNull MenuItem item) {
+        if (item.getItemId() == 1) {
+            Toast.makeText(this, "人物简介——特长", Toast.LENGTH_SHORT).show();
+            Log.d(TAG, "onContextItemSelected: 人物简介——特长");
+        } else if (item.getItemId() == 2) {
+            Toast.makeText(this, "人物简介——战斗力", Toast.LENGTH_SHORT).show();
+            Log.d(TAG, "onContextItemSelected: 人物简介——战斗力");
+        } else if (item.getItemId() == 3) {
+            Toast.makeText(this, "人物简介——经典语录", Toast.LENGTH_SHORT).show();
+            Log.d(TAG, "onContextItemSelected: 人物简介——经典语录");
+        }
+
+        return super.onContextItemSelected(item);
+    }
+
+    // 选项菜单
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         getMenuInflater().inflate(R.menu.main, menu);
@@ -74,6 +143,7 @@ public class FirstActivity extends AppCompatActivity {
 
 /**
  * 添加一个按钮，id = first_btn2，完成单击事件：弹出Toast消息日志，内容自定义，带个人标识
+ * <p>
  * mFirstBtn2 = findViewById(R.id.first_btn2);
  * mFirstBtn2.setOnClickListener(new View.OnClickListener() {
  *