我想写一个模块，在点击一个按钮，相机打开，我可以点击和捕捉图像。如果我不喜欢图像，我可以删除它，然后点击另一个图像，然后选择图像，它应该返回并在活动中显示该图像。
当前回答
以下是完整的代码:
package com.example.cameraa;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
public class MainActivity extends Activity {
Button btnTackPic;
Uri photoPath;
ImageView ivThumbnailPhoto;
static int TAKE_PICTURE = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Get reference to views
btnTackPic = (Button) findViewById(R.id.bt1);
ivThumbnailPhoto = (ImageView) findViewById(R.id.imageView1);
btnTackPic.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, TAKE_PICTURE);
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
if (requestCode == TAKE_PICTURE && resultCode == RESULT_OK) {
Bitmap photo = (Bitmap)intent.getExtras().get("data");
ivThumbnailPhoto.setImageBitmap(photo);
ivThumbnailPhoto.setVisibility(View.VISIBLE);
}
}
}
记住也要为相机添加权限。
其他回答
2021年5月，爪哇
在处理了本文旁边所述的必要权限后， 在manifest中添加:
<uses-permission
android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission
android:name="android.permission.WRITE_EXTERNAL_STORAGE"
android:maxSdkVersion="18" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature
android:name="android.hardware.camera"
android:required="true" />
....
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="${applicationId}.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/provider_paths" />
</provider>
....
其中${applicationId}是应用程序的包名，例如my.app.com。
在res - > xml > provider_paths.xml
<?xml version="1.0" encoding="utf-8"?>
<paths>
<external-files-path name="my_images" path="Pictures" />
<external-path name="external_files" path="."/>
<files-path
name="files" path="." />
<external-cache-path
name="images" path="." />
</paths>
在活动:
private void onClickCaptureButton(View view) {
Intent takePictureIntent_ = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// Ensure that there's a camera activity to handle the intent
if (takePictureIntent_.resolveActivity(getPackageManager()) != null) {
// Create the File where the photo should go
File photoFile_ = null;
try {
photoFile_ = createImageFile();
} catch (IOException ex) {
}
if(photoFile_!=null){
picturePath=photoFile_.getAbsolutePath();
}
// Continue only if the File was successfully created
if (photoFile_ != null) {
Uri photoURI_ = FileProvider.getUriForFile(this,
"my.app.com.fileprovider", photoFile_);
takePictureIntent_.putExtra(MediaStore.EXTRA_OUTPUT, photoURI_);
startActivityForResult(takePictureIntent_, REQUEST_IMAGE_CAPTURE);
}
}
}
还有三招:
...
private static String picturePath;
private static final int REQUEST_IMAGE_CAPTURE = 2;
...
private File createImageFile() throws IOException {
// Create an image file name
String timeStamp_ = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new
Date());
String imageFileName_ = "JPEG_" + timeStamp_ + "_";
File storageDir_ = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
File image_ = File.createTempFile(
imageFileName_, /* prefix */
".jpg", /* suffix */
storageDir_ /* directory */
);
// Save a file: path for use with ACTION_VIEW intents
picturePath= image_.getAbsolutePath();
return image_;
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(requestCode == REQUEST_IMAGE_CAPTURE && resultCode == Activity.RESULT_OK
){
try {
File file_ = new File(picturePath);
Uri uri_ = FileProvider.getUriForFile(this,
"my.app.com.fileprovider", file_);
rasm.setImageURI(uri_);
} catch (/*IO*/Exception e) {
e.printStackTrace();
}
}
}
and
@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
savedInstanceState.putString("safar", picturePath);
// Always call the superclass so it can save the view hierarchy state
super.onSaveInstanceState(savedInstanceState);
}
and:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (savedInstanceState != null) {
picturePath = savedInstanceState.getString("safar");
}
....
}
在活动:
@Override
protected void onCreate(Bundle savedInstanceState) {
image = (ImageView) findViewById(R.id.imageButton);
image.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
try {
SimpleDateFormat sdfPic = new SimpleDateFormat(DATE_FORMAT);
currentDateandTime = sdfPic.format(new Date()).replace(" ", "");
File imagesFolder = new File(IMAGE_PATH, currentDateandTime);
imagesFolder.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = IMAGE_NAME + n + IMAGE_FORMAT;
File file = new File(imagesFolder, fname);
outputFileUri = Uri.fromFile(file);
cameraIntent= new Intent(
android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
startActivityForResult(cameraIntent, CAMERA_DATA);
}catch(Exception e) {
e.printStackTrace();
}
}
});
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
switch(requestCode) {
case CAMERA_DATA :
final int IMAGE_MAX_SIZE = 300;
try {
// Bitmap bitmap;
File file = null;
FileInputStream fis;
BitmapFactory.Options opts;
int resizeScale;
Bitmap bmp;
file = new File(outputFileUri.getPath());
// This bit determines only the width/height of the
// bitmap
// without loading the contents
opts = new BitmapFactory.Options();
opts.inJustDecodeBounds = true;
fis = new FileInputStream(file);
BitmapFactory.decodeStream(fis, null, opts);
fis.close();
// Find the correct scale value. It should be a power of
// 2
resizeScale = 1;
if (opts.outHeight > IMAGE_MAX_SIZE
|| opts.outWidth > IMAGE_MAX_SIZE) {
resizeScale = (int) Math.pow(2, (int) Math.round(Math.log(IMAGE_MAX_SIZE/ (double) Math.max(opts.outHeight, opts.outWidth)) / Math.log(0.5)));
}
// Load pre-scaled bitmap
opts = new BitmapFactory.Options();
opts.inSampleSize = resizeScale;
fis = new FileInputStream(file);
bmp = BitmapFactory.decodeStream(fis, null, opts);
Bitmap getBitmapSize = BitmapFactory.decodeResource(
getResources(), R.drawable.male);
image.setLayoutParams(new RelativeLayout.LayoutParams(
200,200));//(width,height);
image.setImageBitmap(bmp);
image.setRotation(90);
fis.close();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bmp.compress(Bitmap.CompressFormat.JPEG, 70, baos);
imageByte = baos.toByteArray();
break;
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
在layout.xml:
enter code here
<RelativeLayout
android:id="@+id/relativeLayout2"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:id="@+id/imageButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/XXXXXXX"
android:textAppearance="?android:attr/textAppearanceSmall" />
在manifest.xml:
< uses-permission android: name = " android.permission。CAMERA" /> <uses-feature android:name="android.硬件。相机" / >
我创建了一个对话框，可以从图库或相机中选择图像。 回调函数为
Uri，如果图像来自图库 字符串作为文件路径，如果图像是从相机捕获。 从相机中选择的图像需要作为多部分文件数据上传到互联网上
首先，我们要在AndroidManifest中定义权限，因为我们需要在创建文件和从画廊读取图像时写入外部存储
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
中创建file_paths xml文件 应用程序/ src / main / res / xml / file_paths.xml
与路径
<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-path name="external_files" path="."/>
</paths>
然后我们需要定义文件提供者来生成Content uri来访问存储在外部存储器中的文件
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="${applicationId}.provider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_paths" />
</provider>
河流布局
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<androidx.constraintlayout.widget.Guideline
android:id="@+id/guideline2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.50" />
<ImageView
android:id="@+id/gallery"
android:layout_width="48dp"
android:layout_height="48dp"
android:layout_marginStart="8dp"
android:layout_marginTop="32dp"
android:layout_marginEnd="8dp"
android:layout_marginBottom="32dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="@+id/guideline2"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="@drawable/ic_menu_gallery" />
<ImageView
android:id="@+id/camera"
android:layout_width="48dp"
android:layout_height="0dp"
android:layout_marginStart="8dp"
android:layout_marginTop="32dp"
android:layout_marginEnd="8dp"
android:layout_marginBottom="32dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/guideline2"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="@drawable/ic_menu_camera" />
</androidx.constraintlayout.widget.ConstraintLayout>
ImagePicker Dailog
public class ImagePicker extends BottomSheetDialogFragment {
ImagePicker.GetImage getImage;
public ImagePicker(ImagePicker.GetImage getImage, boolean allowMultiple) {
this.getImage = getImage;
}
File cameraImage;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.bottom_sheet_imagepicker, container, false);
view.findViewById(R.id.camera).setOnClickListener(new View.OnClickListener() {@
Override
public void onClick(View view) {
if(ActivityCompat.checkSelfPermission(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[] {
Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE
}, 2000);
} else {
captureFromCamera();
}
}
});
view.findViewById(R.id.gallery).setOnClickListener(new View.OnClickListener() {@
Override
public void onClick(View view) {
if(ActivityCompat.checkSelfPermission(getActivity(), Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[] {
Manifest.permission.READ_EXTERNAL_STORAGE
}, 2000);
} else {
startGallery();
}
}
});
return view;
}
public interface GetImage {
void setGalleryImage(Uri imageUri);
void setCameraImage(String filePath);
void setImageFile(File file);
}@
Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if(resultCode == Activity.RESULT_OK) {
if(requestCode == 1000) {
Uri returnUri = data.getData();
getImage.setGalleryImage(returnUri);
Bitmap bitmapImage = null;
}
if(requestCode == 1002) {
if(cameraImage != null) {
getImage.setImageFile(cameraImage);
}
getImage.setCameraImage(cameraFilePath);
}
}
}
private void startGallery() {
Intent cameraIntent = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
cameraIntent.setType("image/*");
if(cameraIntent.resolveActivity(getActivity().getPackageManager()) != null) {
startActivityForResult(cameraIntent, 1000);
}
}
private String cameraFilePath;
private File createImageFile() throws IOException {
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPEG_" + timeStamp + "_";
File storageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM), "Camera");
File image = File.createTempFile(imageFileName, /* prefix */ ".jpg", /* suffix */ storageDir /* directory */ );
cameraFilePath = "file://" + image.getAbsolutePath();
cameraImage = image;
return image;
}
private void captureFromCamera() {
try {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, FileProvider.getUriForFile(getContext(), BuildConfig.APPLICATION_ID + ".provider", createImageFile()));
startActivityForResult(intent, 1002);
} catch(IOException ex) {
ex.printStackTrace();
}
}
}
像这样调用Activity或fragment 在Fragment/Activity中定义ImagePicker
ImagePicker imagePicker;
然后在点击按钮时调用dailog
imagePicker = new ImagePicker(new ImagePicker.GetImage() {
@Override
public void setGalleryImage(Uri imageUri) {
Log.i("ImageURI", imageUri + "");
String[] filePathColumn = {MediaStore.Images.Media.DATA};
Cursor cursor = getContext().getContentResolver().query(imageUri, filePathColumn, null, null, null);
assert cursor != null;
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
mediaPath = cursor.getString(columnIndex);
// Set the Image in ImageView for Previewing the Media
imagePreview.setImageBitmap(BitmapFactory.decodeFile(mediaPath));
cursor.close();
}
@Override
public void setCameraImage(String filePath) {
mediaPath =filePath;
Glide.with(getContext()).load(filePath).into(imagePreview);
}
@Override
public void setImageFile(File file) {
cameraImage = file;
}
}, true);
imagePicker.show(getActivity().getSupportFragmentManager(), imagePicker.getTag());
你得好好研究一下相机。(我认为要做到你想要的，你必须保存当前的图像到你的应用程序，在那里做选择/删除，然后召回相机再试一次，而不是直接在相机内部重试。)
正如其他人所讨论的，使用data. getextras ().get("data")只会得到低质量的缩略图。
解决方案是通过ACTION_IMAGE_CAPTURE意图传递一个位置，告诉相机在哪里存储全质量图像。
代码是Kotlin，不需要任何权限。
val f = File("${getExternalFilesDir(null)}/imgShot")
val photoURI = FileProvider.getUriForFile(this, "${packageName}.fileprovider", f)
val intent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
.apply { putExtra(MediaStore.EXTRA_OUTPUT, photoURI) }
startActivityForResult(intent, 1234)
然后对拍摄后的结果进行处理:
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
if (requestCode == 1234 && resultCode == Activity.RESULT_OK) {
val bitmap = BitmapFactory.decodeFile(
File("${getExternalFilesDir(null)}/imgShot").toString()
)
// use imageView.setImageBitmap(bitmap) or whatever
}
}
您还需要像这里描述的那样添加一个外部FileProvider。AndroidManifest.xml:
<manifest>
<application>
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="${applicationId}.fileprovider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/provide_paths" />
</provider>
</application>
</manifest>
添加一个新文件app/src/main/res/xml/provide_paths.xml:
<?xml version="1.0" encoding="utf-8"?>
<paths>
<external-path name="external_files" path="." />
</paths>
最后，你应该用你自己的逻辑替换1234来跟踪请求代码(通常是一个包含RequestCode.CAPTURE_IMAGE等成员的枚举)
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