返回Acitivity時傳遞資料

返回Acitivty時需要傳遞數,有以下幾個關鍵地方

• startActivityForResult(intent, SMS_LIST); 告訴系統,這個activity:ContactActivity.class銷燬時,會返回資料
• onActivityResult 方法的監聽
• setResult(1, data);

// MainActivity.java
public class MainActivity extends Activity {
    static final int CONTACT_LIST = 10;
    static final int SMS_LIST = 20;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    public void click(View v) {
        Intent intent = new Intent(this, ContactActivity.class);
        // startActivity(intent);
        // 告訴系統,這個activity:ContactActivity.class銷燬時,會返回資料
        startActivityForResult(intent, CONTACT_LIST);
    }
    public void quick(View v) {
        Intent intent = new Intent(this, SMSActivity.class);
        // startActivity(intent);
        // 告訴系統,這個activity:ContactActivity.class銷燬時,會返回資料
        startActivityForResult(intent, SMS_LIST);
    }
    // 當一個應用返回資料的activity被銷燬了,此方法會呼叫,使用者接收資料
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        EditText et;
        if (requestCode == CONTACT_LIST) {
            et = (EditText) findViewById(R.id.et);
            et.setText(data.getStringExtra("name"));
        }
        if (requestCode == SMS_LIST) {
            et = (EditText) findViewById(R.id.content_et);
            et.setText(data.getStringExtra("content"));
        }
    }
}  

// ContactAcitivity.java
    // 虛構幾個聯絡人
    String[] objects = new String[] { "芙蓉", "四大皆空", "梅西", "傻逼" };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_contact);
        ListView listView = (ListView) findViewById(R.id.lv);
        listView.setAdapter(new ArrayAdapter<String>(this,
                R.layout.item_contact, R.id.tv, objects));
        // 對ListView設定點選監聽,我們需要知道使用者什麼時候點選了條目,還要知道使用者點選的條目
        listView.setOnItemClickListener(new OnItemClickListener() {
            // 使用者點選了哪一個條目,通過這個引數知道
            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                String text = objects[position];
                Intent data = new Intent();
                data.putExtra("name", text);
                // Activity一旦被銷燬,這個data就會傳到activity的呼叫者
                setResult(0, data);
                finish();
            }
        });
    }
}

//activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.example.msgsend.MainActivity" >
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >
        <EditText
            android:id="@+id/et"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:hint="請輸入聯絡人" />
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onClick="click"
            android:text="請選擇聯絡人" />
    </LinearLayout>
    <EditText
        android:id="@+id/content_et"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:lines="5" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="quick"
        android:text="選擇快捷回覆" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="send"
        android:text="傳送" />
</LinearLayout>  

// activity_contact.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <ListView
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</LinearLayout>  

// item_contact.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <TextView
        android:id="@+id/tv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="20sp" />
</LinearLayout>