利用Bundle實現Android Activity間消息的傳遞

程序的效果是活動A向B跳轉的同時發送一字符串，B讀出字符串。

先在AndroidManifest.xml中定義一個新的Activity，target：

1. <?xml version="1.0" encoding="utf-8"?>
2. <manifest xmlns:android="http://schemas.android.com/apk/res/android"
3. package="com.ray.test"
4. android:versionCode="1"
5. android:versionName="1.0">
6. <application android:icon="@drawable/icon" android:label="@string/app_name">
7. <activity android:name=".TestBundle"
8. android:label="@string/app_name">
9. <intent-filter>
10. <action android:name="android.intent.action.MAIN" />
11. <category android:name="android.intent.category.LAUNCHER" />
12. </intent-filter>
13. </activity>
15. <activity android:name=".Target"></activity>
16. </application>
17. <uses-sdk android:minSdkVersion="3" />
18. </manifest>

1. <?xml version="1.0" encoding="utf-8"?>
2. <manifest xmlns:android="http://schemas.android.com/apk/res/android"
3. package="com.ray.test"
4. android:versionCode="1"
5. android:versionName="1.0">
6. <application android:icon="@drawable/icon" android:label="@string/app_name">
7. <activity android:name=".TestBundle"
8. android:label="@string/app_name">
9. <intent-filter>
10. <action android:name="android.intent.action.MAIN" />
11. <category android:name="android.intent.category.LAUNCHER" />
12. </intent-filter>
13. </activity>
15. <activity android:name=".Target"></activity>
16. </application>
17. <uses-sdk android:minSdkVersion="3" />
18. </manifest>

第一個活動的代碼如下：

1. package com.ray.test;
3. import android.app.Activity;
4. import android.content.Intent;
5. import android.os.Bundle;
6. import android.view.MotionEvent;
8. public class TestBundle extends Activity {
9. public void onCreate(Bundle savedInstanceState) {
10. super.onCreate(savedInstanceState);
11. setContentView(R.layout.main);
12. }
14. public boolean onTouchEvent(MotionEvent event) {
15. Intent intent = new Intent();
16. intent.setClass(TestBundle.this, Target.class);
17. Bundle mBundle = new Bundle();
18. mBundle.putString("Data", "ray'blog");//壓入數據
19. intent.putExtras(mBundle);
20. startActivity(intent);
21. finish();
22. return super.onTouchEvent(event);
23. }
24. }

1. package com.ray.test;
3. import android.app.Activity;
4. import android.content.Intent;
5. import android.os.Bundle;
6. import android.view.MotionEvent;
8. public class TestBundle extends Activity {
9. public void onCreate(Bundle savedInstanceState) {
10. super.onCreate(savedInstanceState);
11. setContentView(R.layout.main);
12. }
14. public boolean onTouchEvent(MotionEvent event) {
15. Intent intent = new Intent();
16. intent.setClass(TestBundle.this, Target.class);
17. Bundle mBundle = new Bundle();
18. mBundle.putString("Data", "ray'blog");//壓入數據
19. intent.putExtras(mBundle);
20. startActivity(intent);
21. finish();
22. return super.onTouchEvent(event);
23. }
24. }

將要跳轉到的活動代碼：

1. package com.ray.test;
3. import android.app.Activity;
4. import android.os.Bundle;
6. public class Target extends Activity{
8. public void onCreate(Bundle savedInstanceState) {
9. super.onCreate(savedInstanceState);
10. setContentView(R.layout.main);
11. Bundle bundle = getIntent().getExtras();
12. String data=bundle.getString("Data");//讀出數據
13. setTitle(data);
14. }
15. }

1. package com.ray.test;
3. import android.app.Activity;
4. import android.os.Bundle;
6. public class Target extends Activity{
8. public void onCreate(Bundle savedInstanceState) {
9. super.onCreate(savedInstanceState);
10. setContentView(R.layout.main);
11. Bundle bundle = getIntent().getExtras();
12. String data=bundle.getString("Data");//讀出數據
13. setTitle(data);
14. }
15. }

如果要從Target往TestBundle回傳數據/信息, 可以在TestBundle裡面:
startActivityForResult(intent, 1333); // 1333是request code

然後在Target裡面, 回傳的時候:
Intent data = new Data();
data.putExtra("msg", "my message");
setResult(RESULT_OK, data);
finish();

在TestBundle裡出來傳回來的數據/信息:
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
String msg = data.getExtras.getString("msg");
// ...
}

requestCode 它是作為標識此次intent出現的，他可以設置為任何你想要的int值，從而在onActivityResult中據此做出不同的處理