feat: 上传第四次安卓课程代码(2026年10月16日)

.idea/deploymentTargetSelector.xml

@@ -13,17 +13,6 @@
         </DropdownSelection>
         <DialogSelection />
       </SelectionState>
-      <SelectionState runConfigName="FirstActivity">
-        <option name="selectionMode" value="DROPDOWN" />
-        <DropdownSelection timestamp="2026-09-18T02:12:50.815210100Z">
-          <Target type="DEFAULT_BOOT">
-            <handle>
-              <DeviceId pluginId="LocalEmulator" identifier="path=C:\Users\stu\.android\avd\MyPhone35.avd" />
-            </handle>
-          </Target>
-        </DropdownSelection>
-        <DialogSelection />
-      </SelectionState>
     </selectionStates>
   </component>
 </project>

.idea/gradle.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="GradleMigrationSettings" migrationVersion="1" />
   <component name="GradleSettings">
     <option name="linkedExternalProjectsSettings">
       <GradleProjectSettings>

.idea/misc.xml

@@ -4,7 +4,7 @@
     <option name="optimizeImportsOnTheFly" value="true" />
   </component>
   <component name="ExternalStorageConfigurationManager" enabled="true" />
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" project-jdk-name="jbr-21" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_21" default="true" project-jdk-name="jbr-21" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">

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

@@ -11,6 +11,10 @@ import android.widget.Button;
 import android.widget.LinearLayout;
 import android.widget.Toast;
 
+import androidx.activity.result.ActivityResult;
+import androidx.activity.result.ActivityResultCallback;
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.activity.result.contract.ActivityResultContracts;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
@@ -20,6 +24,9 @@ import androidx.appcompat.widget.PopupMenu;
 public class FirstActivity extends AppCompatActivity {
     private static final String TAG = "FirstActivity";
 
+    // step1: 定义contract启动器类对象，初始化放在Activity生命周期的初始阶段
+    ActivityResultLauncher mActivityResultLauncher;
+
     // 先声明（变量命名：小驼峰）再使用
     // 全局（成员）变量：m开头
     Button mFirstBtn1;
@@ -41,11 +48,27 @@ public class FirstActivity extends AppCompatActivity {
         setContentView(R.layout.first_layout);
         Log.d(TAG, "onCreate: 活动创建成功"); // 组合键2：alter + enter
 
+        // step2: 初始化启动器类对象
+        mActivityResultLauncher = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(),
+                new ActivityResultCallback<ActivityResult>() {  // 触发要求：SecondActivity销毁
+                    @Override
+                    public void onActivityResult(ActivityResult o) {
+                        if (o.getResultCode() == RESULT_OK && o.getData() != null) {
+                            Intent intent = o.getData();
+                            String msgBackFromSecond = intent.getStringExtra("second_backto_first");
+                            Log.d(TAG, "收到Second反馈的数据：" + msgBackFromSecond);
+                        }
+                    }
+                });
+        // step3: 适当的时候启动启动器类
+
         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);
+            intent.putExtra("first_to_second", "Hello, second! I'm first! Are you OK? 6117");
+            mActivityResultLauncher.launch(intent);
+//            startActivity(intent);
         });
 
         mFirstBtn3 = findViewById(R.id.first_btn3);

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

@@ -2,23 +2,81 @@ package com.yanzitong.activitytest6117;
 
 import android.content.Intent;
 import android.os.Bundle;
+import android.text.TextUtils;
+import android.util.Log;
 import android.widget.Button;
+import android.widget.TextView;
+import android.widget.Toast;
 
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.activity.result.contract.ActivityResultContracts;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
 
 public class SecondActivity extends AppCompatActivity {
+
+    public static final String TAG = "SecondActivity";
+    TextView mSecondShowMsgTV;
+
+    ActivityResultLauncher mLauncher;
+
     @Override
     protected void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.second_layout);
+
+        mLauncher = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(),
+                o -> {
+                    if (o.getResultCode() == RESULT_OK && o.getData() != null) {
+                        Intent intent = o.getData();
+                        String msgBackFromThird = intent.getStringExtra("third_backto_second");
+                        Log.d(TAG, "Second收到Third反馈的数据：" + msgBackFromThird);
+                    }
+                });
+
+        // 判断数据是否接受成功
+        Intent intent2 = getIntent();
+        String msgFromFirst = intent2.getStringExtra("first_to_second");
+        mSecondShowMsgTV = findViewById(R.id.second_show_msg_tv);
+        Button mSecondBtn2 = findViewById(R.id.second_btn2);
+        mSecondBtn2.setOnClickListener(v -> {
+            Intent intent3 = new Intent();
+            if (!TextUtils.isEmpty(msgFromFirst)) {
+                intent3.putExtra("second_backto_first", "Hi, first! 我收到你的消息了，谢谢，加油！");
+            } else {
+                intent3.putExtra("second_backto_first", "Hi, first! 我没有收到你的数据，有什么事啊？");
+            }
+            setResult(RESULT_OK, intent3);
+            finish();
+        });
+
+
+        if (TextUtils.isEmpty(msgFromFirst) == false) {
+            Log.d(TAG, "收到来自于First的数据" + msgFromFirst);
+            Toast.makeText(this, "收到来自于First的数据" + msgFromFirst, Toast.LENGTH_SHORT).show();
+            mSecondShowMsgTV.setText(msgFromFirst);
+        } else {
+
+        }
+
         Button mSecondBtn1 = findViewById(R.id.second_btn1);
         mSecondBtn1.setOnClickListener(v -> {
             Intent intent = new Intent(SecondActivity.this, ThirdActivity.class);
-            startActivity(intent);
+            intent.putExtra("second_to_third", "Nice to meet you, Third! 我是Second! 6117");
+
+            mLauncher.launch(intent);
+
+//            startActivity(intent);
         });
     }
 }
+
+/**
+ * your turn:
+ * SecondActivity传递数据给ThirdActivity, "Nice to meet you, Third! 我是Second! 6117"
+ * 日志、Toast、界面显示数据
+ */
+
 /**
  * your turn:
  * 新建UI: third_layout和Java class: thirdActivity

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

@@ -1,8 +1,13 @@
 package com.yanzitong.activitytest6117;
 
 import android.content.Intent;
+import android.net.Uri;
 import android.os.Bundle;
+import android.text.TextUtils;
+import android.util.Log;
 import android.widget.Button;
+import android.widget.TextView;
+import android.widget.Toast;
 
 import androidx.appcompat.app.AppCompatActivity;
 
@@ -11,12 +16,26 @@ public class ThirdActivity extends AppCompatActivity {
     private Button mThirdBtn1;
     private Button mThirdBtn2;
     private Button mThirdBtn3;
+    TextView mThirdShowMsgTV;
+    public static final String TAG = "ThirdActivity";
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.third_layout);
 
+        mThirdShowMsgTV = findViewById(R.id.third_show_msg_tv);
+
+        Intent intent3 = getIntent();
+        String msgFromSecond = intent3.getStringExtra("second_to_third");
+        if (!TextUtils.isEmpty(msgFromSecond)) {
+            Log.d(TAG, "收到来自于Second的数据" + msgFromSecond);
+            Toast.makeText(this, "收到来自于Second的数据" + msgFromSecond, Toast.LENGTH_SHORT).show();
+            mThirdShowMsgTV.setText(msgFromSecond);
+        } else {
+
+        }
+
         mThirdBtn1 = findViewById(R.id.third_btn1);
         mThirdBtn1.setOnClickListener(v -> {    // 项目内部隐式Intent：匹配action和category
             Intent intent = new Intent("com.yanzitong.activitytest6117.action.YZT_FIRST");  // 为FirstActivity定义对应的action
@@ -27,12 +46,28 @@ public class ThirdActivity extends AppCompatActivity {
         mThirdBtn2 = findViewById(R.id.third_btn2);
         mThirdBtn3 = findViewById(R.id.third_btn3);
         mThirdBtn2.setOnClickListener(v -> {
-            Intent intent = new Intent(Intent.ACTION_VIEW);     // 等价于"Intent intent = new Intent(android.intent.action.VIEW)"
+            // 方法二
+            Intent intent = new Intent(Intent.ACTION_VIEW);
+            intent.setData(Uri.parse("https://www.baidu.com"));
             startActivity(intent);
+            // 方法一
+            /* Uri uri = Uri.parse("https://www.baidu.com");
+             * Intent intent = new Intent(Intent.ACTION_VIEW, uri);     // 等价于"Intent intent = new Intent(android.intent.action.VIEW)"
+             * startActivity(intent);
+             */
         });
         mThirdBtn3.setOnClickListener(v -> {
-            Intent intent = new Intent();
+            Intent intent4 =  new Intent();
-            startActivity(intent);
+            if (TextUtils.isEmpty(msgFromSecond) == false) {
+                intent4.putExtra("third_backto_second", "Hi, second! 我收到你的消息了，谢谢，加油！");
+            } else {
+                intent4.putExtra("third_backto_second", "Hi, second! 我没有收到消息！你想跟我说什么？");
+            }
+            setResult(RESULT_OK, intent4);
+            finish();
+//            Intent intent = new Intent(Intent.ACTION_DIAL);
+//            intent.setData(Uri.parse("tel:10000"));
+//            startActivity(intent);
         });
     }
 

app/src/main/res/layout/second_layout.xml

@@ -19,4 +19,11 @@
         android:layout_height="wrap_content"
         android:text="跳转到ThirdActivity"
         android:textAllCaps="false" />
+
+    <Button
+        android:id="@+id/second_btn2"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:text="反馈数据给First"
+        android:textAllCaps="false" />
 </LinearLayout>

app/src/main/res/layout/third_layout.xml

@@ -27,4 +27,13 @@
         android:layout_marginTop="50dp"
         android:text="打开拨号界面"
         android:textAllCaps="false" />
+
+    <TextView
+        android:id="@+id/third_show_msg_tv"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:gravity="center"
+        android:hint="显示数据"
+        android:textColor="#F00"
+        android:textSize="18sp" />
 </LinearLayout>