Android学习（15）-摄像头和相册

如何调用自己手机的拍照功能以及从手机相册选择图片？ 比如找个小例子：

首先，还是弄一个layout先：

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <ImageView
        android:id="@+id/picture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/take_photo"
        android:layout_alignRight="@+id/choose_from_album"
        android:layout_below="@+id/choose_from_album"
        android:layout_marginTop="55dp"
        android:src="@drawable/ic_launcher" />

    <Button
        android:id="@+id/choose_from_album"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/take_photo"
        android:layout_alignBottom="@+id/take_photo"
        android:layout_alignParentRight="true"
        android:layout_marginRight="28dp"
        android:text="从相册选择图片" />

    <Button
        android:id="@+id/take_photo"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="14dp"
        android:layout_marginTop="23dp"
        android:text="拍照" />

</RelativeLayout>

对于该活动，其代码：

public class MainActivity extends Activity {
	
	public static final int TAKE_PHOTO = 1;
	public static final int CROP_PHOTO = 2; //裁剪图片
	
	//用于拍照
	private Button takePhoto;
	private ImageView picture;
	private Uri imageUri; 
	
	//选择图片
	private Button chooseFromAlbum;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		takePhoto = (Button)findViewById(R.id.take_photo);
		picture = (ImageView)findViewById(R.id.picture);
		takePhoto.setOnClickListener(new OnClickListener() {	
			public void onClick(View arg0) {
				//创建File对象，用于存储拍照后的图片
				File outputImage = new File(Environment.getExternalStorageDirectory(),"tempImage.jpg");//参数： 目录  文件
				
				try {
					if(outputImage.exists()){ //文件已经存在就删除
						outputImage.delete();
					}
					outputImage.createNewFile();
				} catch (IOException e) {
					e.printStackTrace();
				}
				
				imageUri = Uri.fromFile(outputImage);//获取图片路径
				Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");//用于启动拍照服务
				intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);//传递数据
				startActivityForResult(intent, TAKE_PHOTO);//启动拍照服务，而且需要返回结果，返回数据由onActivityResult处理
			}
		});
		
		chooseFromAlbum = (Button)findViewById(R.id.choose_from_album);
		chooseFromAlbum.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View arg0) {
				//创建File文件，用于存储选择的照片
				File outputImage = new File(Environment.getExternalStorageDirectory(),"output_image.jpg");
				try {
					if(outputImage.exists()){
						outputImage.delete();
					}
					outputImage.createNewFile();
				} catch (IOException e) {
					e.printStackTrace();
				}
				imageUri = Uri.fromFile(outputImage); //打开相册
				Intent intent = new Intent("android.intent.action.GET_CONTENT");//启动从相册选择图片功能
				intent.setType("image/*");
				intent.putExtra("crop", true);
				intent.putExtra("scale", true);
				intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
				startActivityForResult(intent, CROP_PHOTO);
			}
		});
	}
	
	//用于响应调用活动返回
	protected void onActivityResult(int requestCode, int resultCode, Intent data){
		switch (requestCode) {
		case TAKE_PHOTO:
			if(resultCode == RESULT_OK){
				//如果当前只是拍照，调用裁剪活动
				Intent intent = new Intent("com.android.camera.action.CROP");
				intent.setDataAndType(imageUri, "image/*");
				intent.putExtra("scale", true);
				intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
				startActivityForResult(intent, CROP_PHOTO);//启动剪裁活动
			}
			break;
		case CROP_PHOTO:
			if(resultCode == RESULT_OK){
				try {
					Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri)); //跨程序共享数据，共享输入数据
					picture.setImageBitmap(bitmap);
				} catch (FileNotFoundException e) {
					e.printStackTrace();
				}
			}
			break;
		default:
			break;
		}
	}

}

在配置文件中要配置权限说明：

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>