public class PhotoTest extends Activity {

	private ImageView iv;
	private Bitmap bitmap;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.photo);
		iv = (ImageView) findViewById(R.id.photo);
		
	}
	
	public void pai(View view){
		//调用系统拍照功能的Action
		Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
		//跳转到拍照的Action
		startActivityForResult(intent, 0);
	}
	
	//startActivityForResult(intent, 0)所返回数据的方法
	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {
		// TODO Auto-generated method stub
		if(data!=null){
			//获取拍摄的图片
			bitmap = (Bitmap) data.getExtras().get("data");
			//设置图片的两种方式：
			//第一种方式：直接调用setImageBitmap方法把bitmap对象放进去
			//iv.setImageBitmap(bitmap);
			//第二种方式：通过BitmapDrawable把bitmap对象转为drawable类型，再调用setImageDrawable()方法设置ImageView显示的图片
			BitmapDrawable db = new BitmapDrawable(bitmap);
			Drawable drawable = db;
			iv.setImageDrawable(drawable);
			try {
				OutputStream os = new FileOutputStream(Environment.getExternalStorageDirectory().getAbsolutePath()+ "/2015011301.jpg");
				//把图片对象（bitmap）内容压缩为字节 放入写流
				bitmap.compress(CompressFormat.JPEG, 100, os);
				os.flush();
			} catch (FileNotFoundException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		
		super.onActivityResult(requestCode, resultCode, data);
	}
	
	
}

.xml代码：

<?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:gravity="center"
    android:orientation="vertical" >

    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="拍照" 
        android:onClick="pai"/>
    
    <ImageView 
        android:id="@+id/photo"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        
        />

</LinearLayout>

Android多媒体之拍照