意图intent的作用一

意图的作用：

1 用于激活其他组件

写法一：

Intent intent = new Intent(this, MyService.class);//设置意图的上下文环境和需要激活的组件

写法二：

Intent intent = new Intent();

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

startActivity(intent); //通过这个意图来激活Activity

2 用于携带数据

======================================================================

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="huawei.com.manyActivity"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="7" />

<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="OtherActivity" />
</application>
</manifest>

========================================================================

<?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"
/>
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="打开其他的Activity"
/>
</LinearLayout>

=========================================================================

具体应用

package huawei.com.manyActivity;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

Button button = (Button) findViewById(R.id.button);
button.setOnClickListener(new OnClickListener() {

public void onClick(View v) {

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

/*intent.putExtra("name", "华为公司");
intent.putExtra("department", "特种终端");*/

Bundle bundle = new Bundle();
bundle.putString("name", "华为公司");
bundle.putString("department", "特种终端");
intent.putExtras(bundle);

//startActivity(intent);

startActivityForResult(intent, 100);//等待结果的Acitivity


}
});

}
//等待的返回结果在这里处理
protected void onActivityResult(int requestCode, int resultCode, Intent data) {

Toast.makeText(this, data.getExtras().getString("result"), 1).show();

super.onActivityResult(requestCode, resultCode, data);
}
}

=======================================================

<?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="这是other的Activity"
android:id="@+id/result"
/>
<Button
android:id="@+id/close"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="关闭Activity"
/>
</LinearLayout>

=======================================================

package huawei.com.manyActivity;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class OtherActivity extends Activity {

public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.other);

Intent intent = this.getIntent();
String name = (String) intent.getExtras().get("name");
String department = (String) intent.getExtras().get("department");

TextView textView = (TextView) findViewById(R.id.result);
textView.setText("name "+name+" department "+department);


Button closeBtn = (Button) findViewById(R.id.close);
closeBtn.setOnClickListener(new OnClickListener() {

public void onClick(View v) {

Intent intent = new Intent();
intent.putExtra("result", "返回值：企业无线特种终端");
setResult(20, intent);
finish();

}
});

}

}

=======================================================