本文介绍如何从相册,摄像头中获取图片Bitmap和图片的路径Path.
并且实现可以剪裁图片,和压缩图片.
1:打开图片选择器(系统默认就提供了)
static final int REQUEST_CODE_PHOTO = 100;
public void getPhotoFromPhotos() {
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.addCategory(Intent.CATEGORY_OPENABLE);
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "选择图片"), REQUEST_CODE_PHOTO);
}
2:打开相机拍照图片
static final int REQUEST_CODE_CAMERA = 101;
public void getPhotoFromCamera() {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);
imageUri = Uri.fromFile(new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM),
UUID.randomUUID() + ".jpg"));//需要提供图片的保存路径
intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri); // set the image file name
startActivityForResult(intent, REQUEST_CODE_CAMERA);
}
3:通过图片路径剪裁图片
/**
* 用给定的uri,调用 裁剪程序
*/
private void cropImageByUri(Uri uri, int outputX, int outputY, int requestCode) {
Intent intent = new Intent("com.android.camera.action.CROP");
intent.setDataAndType(uri, "image/*");
intent.putExtra("crop", "true");
intent.putExtra("aspectX", 2);
intent.putExtra("aspectY", 1);
intent.putExtra("outputX", outputX);
intent.putExtra("outputY", outputY);
intent.putExtra("scale", true);
intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);
intent.putExtra("return-data", false);
intent.putExtra("outputFormat", Bitmap.CompressFormat.JPEG.toString());
intent.putExtra("noFaceDetection", true); // no face detection
startActivityForResult(intent, requestCode);
}
4:处理返回的data数据
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK && requestCode == REQUEST_CODE_PHOTO && data != null) {
imageUri = data.getData();
if (imageUri != null) {//相册选择
//todo
} else {//拍照选择,不能设置MediaStore.EXTRA_OUTPUT
Bundle extras = data.getExtras();
//todo
}
} else if (resultCode == RESULT_OK && requestCode == REQUEST_CODE_CAMERA && imageUri != null) {//拍照选择,设置MediaStore.EXTRA_OUTPUT
//todo
} else if (resultCode == RESULT_OK && requestCode == 130 && imageUri != null) {//拍照选择,设置MediaStore.EXTRA_OUTPUT
//todo
}
}
5:从uri中获取bitmap对象
private Bitmap getImage(Uri imageUri) {
return MediaStore.Images.Media.getBitmap(this.getContentResolver(), imageUri);
}
6:从uri中获取path路径
public static String getPathFromUri(@NonNull Context context, @NonNull Uri uri) {
String path = "";
if (uri.getScheme().equalsIgnoreCase(ContentResolver.SCHEME_CONTENT)) {
Cursor cursor;
final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
String wholeID = DocumentsContract.getDocumentId(uri);
String id = wholeID.split(":")[1];
String[] column = {MediaStore.Images.Media.DATA};
String sel = MediaStore.Images.Media._ID + "=?";
cursor = context.getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, column,
sel, new String[]{id}, null);
int columnIndex = cursor.getColumnIndex(column[0]);
if (cursor.moveToFirst()) {
path = cursor.getString(columnIndex);
}
cursor.close();
} else {
String[] projection = {MediaStore.Images.Media.DATA};
cursor = context.getContentResolver().query(uri, projection, null, null, null);
int column_index = cursor.getColumnIndexOrThrow(projection[0]);
cursor.moveToFirst();
path = cursor.getString(column_index);
cursor.close();
}
} else if (uri.getScheme().equalsIgnoreCase(ContentResolver.SCHEME_FILE)) {
path = uri.getPath();
}
return path;
}
7:图片压缩,缩放
/**
* scale image
*
* @param org
* @param newWidth
* @param newHeight
* @return
*/
public static Bitmap scaleImageTo(Bitmap org, int newWidth, int newHeight) {
float scaleWidth = (float) newWidth / org.getWidth();
float scaleHeight = (float) newHeight / org.getHeight();
float scale = Math.max(scaleWidth, scaleHeight);
return scaleImage(org, scale, scale);
}
/**
* scale image
*
* @param org
* @param scaleWidth sacle of width
* @param scaleHeight scale of height
* @return
*/
public static Bitmap scaleImage(Bitmap org, float scaleWidth, float scaleHeight) {
if (org == null) {
return null;
}
Matrix matrix = new Matrix();
matrix.postScale(scaleWidth, scaleHeight);
return Bitmap.createBitmap(org, 0, 0, org.getWidth(), org.getHeight(), matrix, true);
}
public static int calculateInSampleSize(BitmapFactory.Options options,
int reqWidth, int reqHeight) {
// 源图片的高度和宽度
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
// 计算出实际宽高和目标宽高的比率
final int heightRatio = Math.round((float) height / (float) reqHeight);
final int widthRatio = Math.round((float) width / (float) reqWidth);
// 选择宽和高中最小的比率作为inSampleSize的值，这样可以保证最终图片的宽和高
// 一定都会大于等于目标的宽和高。
inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
}
return inSampleSize;
}
public static Bitmap decodeSampledBitmapFromResource(Resources res, int resId,
int reqWidth, int reqHeight) {
// 第一次解析将inJustDecodeBounds设置为true，来获取图片大小
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
// 调用上面定义的方法计算inSampleSize值
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// 使用获取到的inSampleSize值再次解析图片
options.inJustDecodeBounds = false;
return BitmapFactory.decodeResource(res, resId, options);
}
源码: https://github.com/angcyo/PhotoGetDemo
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