试试这两种方法：
首先，向他们显示一个对话框以选择选项：
private void selectImage() {
final CharSequence[] items = { getString(R.string.take_photo), getString(R.string.choose_from_gallery),
getString(R.string.cancel) };
AlertDialog.Builder builder = new AlertDialog.Builder(MyAccountActivity.this);
builder.setTitle(getString(R.string.upload_photo));
builder.setItems(items, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int item) {
if (items[item].equals(getString(R.string.take_photo))) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, REQUEST_CAMERA);
} else if (items[item].equals(getString(R.string.choose_from_gallery))) {
Intent intent = new Intent(
Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
intent.setType("image/*");
startActivityForResult(
Intent.createChooser(intent, getString(R.string.select_file)),
SELECT_FILE);
} else if (items[item].equals(getString(R.string.choose_from_gallery))) {
dialog.dismiss();
}
}
});
builder.show();
}
当用户拍照或从图库中选择时接收实际图像：
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == Activity.RESULT_OK) {
if (requestCode == SELECT_FILE)
onSelectFromGalleryResult(data);
else if (requestCode == REQUEST_CAMERA)
onCaptureImageResult(data);
else if (requestCode == Crop.REQUEST_CROP) {
handleCrop(resultCode, data);
}
}
}
接下来是根据需要处理裁剪 - 这不是此代码工作所必需的，但您可以使用它；
private void onCaptureImageResult(Intent data) {
beginCrop(data.getData());
}
@SuppressWarnings("deprecation")
private void onSelectFromGalleryResult(Intent data) {
Uri selectedImageUri = data.getData();
beginCrop(selectedImageUri);
}
private void beginCrop(Uri source) {
Uri destination = Uri.fromFile(new File(getCacheDir(), "cropped"));
Crop.of(source, destination).asSquare().start(this);
}
private void handleCrop(int resultCode, Intent result) {
if (resultCode == RESULT_OK) {
try {
Bitmap bitmap = handleSamplingAndRotationBitmap(this, Crop.getOutput(result));
saveToInternalStorage(bitmap);
mUserProfilePhoto.setImageBitmap(readFromInternalStorage("profile.png"));
}catch (IOException e){ /* do nothing here */}
} else if (resultCode == Crop.RESULT_ERROR) {
Toast.makeText(this, Crop.getError(result).getMessage(), Toast.LENGTH_SHORT).show();
}
}
有时，如果图像不直立，您可能需要旋转图像：
private static Bitmap handleSamplingAndRotationBitmap(Context context, Uri selectedImage) throws IOException {
int MAX_HEIGHT = 1024;
int MAX_WIDTH = 1024;
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
InputStream imageStream = context.getContentResolver().openInputStream(selectedImage);
BitmapFactory.decodeStream(imageStream, null, options);
imageStream.close();
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, MAX_WIDTH, MAX_HEIGHT);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
imageStream = context.getContentResolver().openInputStream(selectedImage);
Bitmap img = BitmapFactory.decodeStream(imageStream, null, options);
img = rotateImageIfRequired(img, selectedImage);
return img;
}
private static int calculateInSampleSize(BitmapFactory.Options options,
int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
// Calculate ratios of height and width to requested height and width
final int heightRatio = Math.round((float) height / (float) reqHeight);
final int widthRatio = Math.round((float) width / (float) reqWidth);
// Choose the smallest ratio as inSampleSize value, this will guarantee a final image
// with both dimensions larger than or equal to the requested height and width.
inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
// This offers some additional logic in case the image has a strange
// aspect ratio. For example, a panorama may have a much larger
// width than height. In these cases the total pixels might still
// end up being too large to fit comfortably in memory, so we should
// be more aggressive with sample down the image (=larger inSampleSize).
final float totalPixels = width * height;
// Anything more than 2x the requested pixels we'll sample down further
final float totalReqPixelsCap = reqWidth * reqHeight * 2;
while (totalPixels / (inSampleSize * inSampleSize) > totalReqPixelsCap) {
inSampleSize++;
}
}
return inSampleSize;
}
private static Bitmap rotateImageIfRequired(Bitmap img, Uri selectedImage) throws IOException {
ExifInterface ei = new ExifInterface(selectedImage.getPath());
int orientation = ei.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
switch (orientation) {
case ExifInterface.ORIENTATION_ROTATE_90:
return rotateImage(img, 90);
case ExifInterface.ORIENTATION_ROTATE_180:
return rotateImage(img, 180);
case ExifInterface.ORIENTATION_ROTATE_270:
return rotateImage(img, 270);
default:
return img;
}
}
private static Bitmap rotateImage(Bitmap img, int degree) {
Matrix matrix = new Matrix();
matrix.postRotate(degree);
Bitmap rotatedImg = Bitmap.createBitmap(img, 0, 0, img.getWidth(), img.getHeight(), matrix, true);
img.recycle();
return rotatedImg;
}
用户从图库中选择或从相机中获取后立即存储：
private boolean saveToInternalStorage(Bitmap image) {
try {
FileOutputStream fos = this.openFileOutput("profile.png", Context.MODE_PRIVATE);
image.compress(Bitmap.CompressFormat.PNG, 100, fos);
fos.close();
return true;
} catch (Exception e) {
return false;
}
}
现在从存储中读取：
private Bitmap readFromInternalStorage(String filename){
try {
File filePath = this.getFileStreamPath(filename);
FileInputStream fi = new FileInputStream(filePath);
return BitmapFactory.decodeStream(fi);
} catch (Exception ex) { /* do nothing here */}
return null;
}
在 onResume 中，我有这段代码可以将图像设置为 imageview：
@Override
public void onResume(){
super.onResume();
Bitmap savedProfilePhoto = readFromInternalStorage("profile.png");
if (savedProfilePhoto != null){
mUserProfilePhoto.setImageBitmap(savedProfilePhoto);
}
}
几乎在这里完成：
将此添加到您的依赖项（build.gradle）
dependencies{
compile 'com.soundcloud.android:android-crop:1.0.1@aar'
}
最后，在您的 android 清单文件中，为了使裁剪库正常工作，请添加以下内容：
<activity android:name="com.soundcloud.android.crop.CropImageActivity"/>
这就是您在应用程序中启用从图库中选择图像或使用相机拍照所需的全部内容！
我希望这对您和其他有需要的人有所帮助，祝您好运！