用Android Studio编写拍照和从相册选取图片的功能

为了在Android Studio中实现拍照和从相册选取图片的功能，您需要执行以下操作：

1.添加以下权限到AndroidManifest.xml文件中：

<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-feature android:name="android.hardware.camera"/>

2.在主要活动（Main Activity）中添加以下代码来调用相机并拍照：

private static final int CAMERA_REQUEST = 1888;

private Button button;
private ImageView imageView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

button = (Button) findViewById(R.id.button);
imageView = (ImageView)findViewById(R.id.imageView);

button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, CAMERA_REQUEST);
}
});
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);

if (requestCode == CAMERA_REQUEST && resultCode == Activity.RESULT_OK) {
Bitmap photo = (Bitmap) data.getExtras().get("data");
imageView.setImageBitmap(photo);
}
}

3.在主要活动中添加以下代码来调用相册和选取图片：

private static final int PICK_IMAGE_REQUEST = 1;

private Button button1;
private ImageView imageView;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

button1 = (Button) findViewById(R.id.button1);
imageView = (ImageView)findViewById(R.id.imageView);

button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent galleryIntent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(galleryIntent, PICK_IMAGE_REQUEST);
}
});
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);

if (requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK && null != data) {
Uri selectedImage = data.getData();
String[] filePathColumn = { MediaStore.Images.Media.DATA };
Cursor cursor = getContentResolver().query(selectedImage,filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
String picturePath = cursor.getString(columnIndex);
cursor.close();
imageView.setImageBitmap(BitmapFactory.decodeFile(picturePath));
}
}

确保您在AndroidManifest.xml文件中添加了必要的权限，并按照上述代码操作，就可以实现在Android Studio中拍照和从相册选取图片的功能。