android如何从系统或相机中获取照片

public class MainActivity extends Activity

{

private static final int PHOTO_REQUEST_CAREMA = 1;// 拍照

private static final int PHOTO_REQUEST_GALLERY = 2;// 从相册中选择

private static final int PHOTO_REQUEST_CUT = 3;// 结果

private ImageView iv_p_w_picpath;

/* 头像名称 */

private static final String PHOTO_FILE_NAME = "temp_photo.jpg";

private File tempFile;

@Override

protected void onCreate(Bundle savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

this.iv_p_w_picpath = (ImageView) this.findViewById(R.id.iv_p_w_picpath);

}

/*

* 从相册获取

*/

public void gallery(View view)

{

// 激活系统图库，选择一张图片

Intent intent = new Intent(Intent.ACTION_PICK);

intent.setType("p_w_picpath/*");

// 开启一个带有返回值的Activity，请求码为PHOTO_REQUEST_GALLERY

startActivityForResult(intent, PHOTO_REQUEST_GALLERY);

}

/*

* 从相机获取

*/

public void camera(View view)

{

// 激活相机

Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");

// 判断存储卡是否可以用，可用进行存储

if (hasSdcard())

{

tempFile = new File(Environment.getExternalStorageDirectory(),

PHOTO_FILE_NAME);

// 从文件中创建uri

Uri uri = Uri.fromFile(tempFile);

intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);

}

// 开启一个带有返回值的Activity，请求码为PHOTO_REQUEST_CAREMA

startActivityForResult(intent, PHOTO_REQUEST_CAREMA);

}

/*

* 剪切图片

*/

private void crop(Uri uri)

{

// 裁剪图片意图

Intent intent = new Intent("com.android.camera.action.CROP");

intent.setDataAndType(uri, "p_w_picpath/*");

intent.putExtra("crop", "true");

// 裁剪框的比例，1：1

intent.putExtra("aspectX", 1);

intent.putExtra("aspectY", 1);

// 裁剪后输出图片的尺寸大小

intent.putExtra("outputX", 250);

intent.putExtra("outputY", 250);

intent.putExtra("outputFormat", "JPEG");// 图片格式

intent.putExtra("noFaceDetection", true);// 取消人脸识别

intent.putExtra("return-data", true);

// 开启一个带有返回值的Activity，请求码为PHOTO_REQUEST_CUT

startActivityForResult(intent, PHOTO_REQUEST_CUT);

}

/*

* 判断sdcard是否被挂载

*/

private boolean hasSdcard()

{

if (Environment.getExternalStorageState().equals(

Environment.MEDIA_MOUNTED))

{

return true;

} else

{

return false;

}

}

@Override

protected void onActivityResult(int requestCode, int resultCode, Intent data)

{

if (requestCode == PHOTO_REQUEST_GALLERY)

{

// 从相册返回的数据

if (data != null)

{

// 得到图片的全路径

Uri uri = data.getData();

crop(uri);

}

} else if (requestCode == PHOTO_REQUEST_CAREMA)

{

// 从相机返回的数据

if (hasSdcard())

{

crop(Uri.fromFile(tempFile));

} else

{

Toast.makeText(MainActivity.this, "未找到存储卡，无法存储照片！", 0).show();

}

} else if (requestCode == PHOTO_REQUEST_CUT)

{

// 从剪切图片返回的数据

if (data != null)

{

Bitmap bitmap = data.getParcelableExtra("data");

this.iv_p_w_picpath.setImageBitmap(bitmap);

}

try

{

// 将临时文件删除

tempFile.delete();

} catch (Exception e)

{

e.printStackTrace();

}

}

super.onActivityResult(requestCode, resultCode, data);

}

}