Android之Intent的使用

Intent:提供了一種通用的消息系統，它容許在你的應用程序與其餘的應用程序間傳遞Intent來執行動做和產生事件.至關於一個請求.
Intent能夠激活Android應用的三個核心組件：活動(Activity)、服務(Service)、廣播接收器(BroadcastReceiver).
Intent中有兩種意圖：分別是顯式意圖和隱式意圖
一、顯示意圖：明確指定了組件名的Intent.
三種方式：
1)

Intent intent= new Intent();
intent.setComponent( new Component(MainActivity.this,OtherActivity.class));

2)                                                        

intent.setClass(MainActivity. this,OtherActivity. class);

3)

Intent intent= new Intent(MainActivity. this,OtherActivity. class);

二、隱式意圖：沒有明確指定組件名的Intent.
Android系統會根據隱式意圖中設置的動做(action)、類別(category)、數據(data)找到最合適的組件來處理這個意圖.
例如：撥打電話的意圖：

Uri uri=Uri.parse( "tel:"+phoneCode);
Intent intent= new Intent(Intent.ACTION_CALL,uri);

下面就兩種意圖分別舉例：
首先，新建一個Android項目--->取名IntentDemo
MainActivity.java的代碼以下：

public class MainActivity extends Activity {
         private EditText name = null;
         private Button submit = null;
        @Override
         public void onCreate(Bundle savedInstanceState) {
                 super.onCreate(savedInstanceState);
                setContentView(R.layout.main);
                
                name = (EditText)findViewById(R.id.etname);
                submit = (Button)findViewById(R.id.submit);
                
                submit.setOnClickListener( new View.OnClickListener() {
                      @Override
                      public void onClick(View v) {
        
                            String content = name.getText().toString();
                            Intent intent = new Intent();
                            intent.putExtra( "name", content);
                            intent.setClass(MainActivity. this, OtherActivity. class);
                            MainActivity. this.startActivity(intent);
                      }
               });
        }
}

Main.xml的佈局

<?xml version= "1.0" encoding= "utf-8"?>
<LinearLayout xmlns:android= "http://schemas.android.com/apk/res/android"
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        >
     <TextView
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         android:text="@string/name"
         android:id="@+id/name"
        />
        
        <EditText
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         android:id="@+id/etname"
  />
  
  <Button
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:text="@string/submit"
         android:id="@+id/submit"
    />

</LinearLayout>

strings.xml

<?xml version= "1.0" encoding= "utf-8"?>
<resources>
        <string name= "hello">Hello World, MainActivity!</string>
        <string name= "app_name">Intent應用</string>
        <string name= "name">你最親愛的人 ：</string>
        <string name= "submit">提交無返</string>
        <string name= "resubmit">提交有返</string>
        <string name= "resend">返回</string>
</resources>

OtherActivity.java的代碼以下：

public class OtherActivity extends Activity {
        
   private TextView result = null;
  @Override
   protected void onCreate(Bundle savedInstanceState) {
     // TODO Auto-generated method stub
     super.onCreate(savedInstanceState);
    this.setContentView(R.layout.other);
    
    result = (TextView)findViewById(R.id.result);
    
    Intent intent = this.getIntent();
    String content = intent.getExtras().getString( "name");
    result.setText(content);
    
  }
}

other.xml的佈局

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

AndroidManifest.xml

<?xml version= "1.0" encoding= "utf-8"?>
<manifest xmlns:android= "http://schemas.android.com/apk/res/android"
            package="com.gem.teset"
            android:versionCode="1"
            android:versionName="1.0">
        <application android:icon="@drawable/icon" android:label="@string/app_name">
                <activity android:name=".MainActivity"
                                    android:label="@string/app_name">
                        <intent-filter>
                                <action android:name="android.intent.action.MAIN" />
                                <category android:name="android.intent.category.LAUNCHER" />
                        </intent-filter>
                </activity>
                
                <activity
                     android:name=".OtherActivity"
                     android:label="@string/app_name"
                />
        </application>
        <uses-sdk android:minSdkVersion="8" />

</manifest>

效果圖以下：

 


首先，新建一個Android項目--->取名IntentPhoneUrl
MainActivity.java的代碼以下：

public class MainActivity extends Activity {
   private EditText num = null;
   private Button call = null;
  @Override
   public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    num = (EditText)findViewById(R.id.num);
    call =(Button)findViewById(R.id.call);

    call.setOnClickListener( new View.OnClickListener() {

      @Override
       public void onClick(View v) {
        String phoneNum = num.getText().toString();
        Uri uri = Uri.parse( "tel:" + phoneNum);
        Intent intent = new Intent(Intent.ACTION_CALL,uri);
        startActivity(intent);

      }
    });
  }
}

main.xml的佈局

<?xml version= "1.0" encoding= "utf-8"?>
<LinearLayout xmlns:android= "http://schemas.android.com/apk/res/android"
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        >
     <TextView    
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello"
        />
         <EditText
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:id="@+id/num"
            />
            
            <Button
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
                 android:id="@+id/call"
                 android:text="撥號"
            />
</LinearLayout>

strings.xml

<?xml version= "1.0" encoding= "utf-8"?>
<resources>
        <string name= "hello">電話號碼</string>
        <string name= "app_name">IntentPhoneUrl</string>
</resources>

AndroidManifest.xml

<?xml version= "1.0" encoding= "utf-8"?>
<manifest xmlns:android= "http://schemas.android.com/apk/res/android"
            package="com.gem.test"
            android:versionCode="1"
            android:versionName="1.0">
        <application android:icon="@drawable/icon" android:label="@string/app_name">
                <activity android:name=".MainActivity"
                                    android:label="@string/app_name">
                        <intent-filter>
                                <action android:name="android.intent.action.MAIN" />
                                <category android:name="android.intent.category.LAUNCHER" />
                        </intent-filter>
                </activity>

        </application>
        <uses-sdk android:minSdkVersion="8" />
        <!-- 撥號權限 -->
        <uses-permission android:name="android.permission.CALL_PHONE"/>
        <!-- 發送信息權限 -->
        <uses-permission android:name="android.permission.SEND_SMS"/>
</manifest>

效果圖以下：