MainActivity如下:

package cn.com.bravesoft.testintent;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.app.Activity;
import android.content.Intent;
/**
 * 
 *官方资料:
 *1 权限设置
 *  http://developer.android.com/reference/android/Manifest.permission.html
 *2 系统Intent
 *  http://developer.android.com/reference/android/content/Intent.html#ACTION_CALL
 */
public class MainActivity extends Activity {
	private Button mTelephoneButton;
	private Button mPhotosButton;
	private Button mBrowserButton;
	private Button mCameraButton;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		init();
	}
    private void init(){
    	mTelephoneButton=(Button) findViewById(R.id.callTelephoneButton);
    	mTelephoneButton.setOnClickListener(new ButtonOnClickListenerImpl());
    	mPhotosButton=(Button) findViewById(R.id.browsephotosButton);
    	mPhotosButton.setOnClickListener(new ButtonOnClickListenerImpl());
    	mBrowserButton=(Button) findViewById(R.id.openBrowserButton);
    	mBrowserButton.setOnClickListener(new ButtonOnClickListenerImpl());
    	mCameraButton=(Button) findViewById(R.id.openCameraButton);
    	mCameraButton.setOnClickListener(new ButtonOnClickListenerImpl());
    }
    private class ButtonOnClickListenerImpl implements OnClickListener{
		@Override
		public void onClick(View v) {
			switch (v.getId()) {
			case R.id.callTelephoneButton:
				//拨打电话
				Intent telephoneIntent=new Intent();
				telephoneIntent.setAction("android.intent.action.CALL");
				telephoneIntent.setData(Uri.parse("tel:"+"150028068"));
				startActivity(telephoneIntent);
				break;
			case R.id.browsephotosButton:
				//查看图片
                Intent galleryIntent=new Intent();
                galleryIntent.setAction(Intent.ACTION_GET_CONTENT);
                galleryIntent.setType("image/*");
                startActivity(galleryIntent);
				break;
			case R.id.openBrowserButton:
				 //打开浏览器
				 Intent browserIntent=new Intent();
				 browserIntent.setAction(Intent.ACTION_VIEW);
				 browserIntent.setData(Uri.parse("http://www.ifeng.com"));
	             startActivity(browserIntent);
				break;
			case R.id.openCameraButton:
				//打开照相机
				Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);  
				startActivity(cameraIntent);
				break;

			default:
				break;
			}
		}
    	
    }
}

main.xml如下:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"
    android:gravity="center_horizontal"
    >
   <Button
       android:id="@+id/callTelephoneButton"
       android:layout_width="150dip"
       android:layout_height="40dip"
       android:gravity="center"
       android:text="@string/callTelephone"
       android:layout_marginTop="50dip"
       android:textSize="20sp"
       />
    <Button
       android:id="@+id/browsephotosButton"
       android:layout_width="150dip"
       android:layout_height="40dip"
       android:gravity="center"
       android:text="@string/browsephotos"
       android:layout_marginTop="50dip"
       android:textSize="20sp"
       />
     <Button
       android:id="@+id/openBrowserButton"
       android:layout_width="150dip"
       android:layout_height="40dip"
       android:gravity="center"
       android:text="@string/openBrowser"
       android:layout_marginTop="50dip"
       android:textSize="20sp"
       />
      <Button
       android:id="@+id/openCameraButton"
       android:layout_width="150dip"
       android:layout_height="40dip"
       android:gravity="center"
       android:text="@string/openCamera"
       android:layout_marginTop="50dip"
       android:textSize="20sp"
       />
   
</LinearLayout>