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
坏的质量
根据我的经验，如果我们使用
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, RESULT_ADD_PHOTO);
和处理onActivityResult()
Bitmap thumbnail= (Bitmap) data.getExtras().get("data");
它只会给你一个缩略图，当然有一个坏的质量。
不错的质量
您可以显示相机和保存您的图像文件在公共目录，例如在文档目录
在onClick()中使用这个
String imagePath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS) +
File.separator + "your_image_name.jpeg";
Intent i =new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
imageFile = new File(imagePath );
i.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(imageFile));
startActivityForResult(i, RESULT_ADD_PHOTO);
在onActivityResult()中
Bitmap imageBitmap1 = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
Matrix matrix = new Matrix();
matrix.postRotate(90);
Bitmap imageBitmap = Bitmap.createBitmap(imageBitmap1, 0, 0, imageBitmap1.getWidth(), imageBitmap1.getHeight(), matrix, true);
binding.imageView.setImageBitmap(imageBitmap);
我使用postRotate()，因为在我的代码中，图像结果向左旋转，所以我需要将其旋转90
其他回答
坏的质量
根据我的经验，如果我们使用
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, RESULT_ADD_PHOTO);
和处理onActivityResult()
Bitmap thumbnail= (Bitmap) data.getExtras().get("data");
它只会给你一个缩略图，当然有一个坏的质量。
不错的质量
您可以显示相机和保存您的图像文件在公共目录，例如在文档目录
在onClick()中使用这个
String imagePath = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS) +
File.separator + "your_image_name.jpeg";
Intent i =new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
imageFile = new File(imagePath );
i.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(imageFile));
startActivityForResult(i, RESULT_ADD_PHOTO);
在onActivityResult()中
Bitmap imageBitmap1 = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
Matrix matrix = new Matrix();
matrix.postRotate(90);
Bitmap imageBitmap = Bitmap.createBitmap(imageBitmap1, 0, 0, imageBitmap1.getWidth(), imageBitmap1.getHeight(), matrix, true);
binding.imageView.setImageBitmap(imageBitmap);
我使用postRotate()，因为在我的代码中，图像结果向左旋转，所以我需要将其旋转90
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" / >
在这里你可以打开相机或图库，并设置选定的图像到imageview
private static final String IMAGE_DIRECTORY = "/YourDirectName";
private Context mContext;
private CircleImageView circleImageView; // imageview
private int GALLERY = 1, CAMERA = 2;
在清单中添加权限
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="ANDROID.PERMISSION.READ_EXTERNAL_STORAGE" />
在onCreate ()
requestMultiplePermissions(); // check permission
circleImageView = findViewById(R.id.profile_image);
circleImageView.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
showPictureDialog();
}
});
显示选项对话框(用于从相机或图库中选择图像)
private void showPictureDialog() {
AlertDialog.Builder pictureDialog = new AlertDialog.Builder(this);
pictureDialog.setTitle("Select Action");
String[] pictureDialogItems = {"Select photo from gallery", "Capture photo from camera"};
pictureDialog.setItems(pictureDialogItems,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
switch (which) {
case 0:
choosePhotoFromGallary();
break;
case 1:
takePhotoFromCamera();
break;
}
}
});
pictureDialog.show();
}
从图库获取照片
public void choosePhotoFromGallary() {
Intent galleryIntent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(galleryIntent, GALLERY);
}
从相机中获取照片
private void takePhotoFromCamera() {
Intent intent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, CAMERA);
}
一旦图像被选中或捕获，
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == this.RESULT_CANCELED) {
return;
}
if (requestCode == GALLERY) {
if (data != null) {
Uri contentURI = data.getData();
try {
Bitmap bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), contentURI);
String path = saveImage(bitmap);
Toast.makeText(getApplicationContext(), "Image Saved!", Toast.LENGTH_SHORT).show();
circleImageView.setImageBitmap(bitmap);
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Failed!", Toast.LENGTH_SHORT).show();
}
}
} else if (requestCode == CAMERA) {
Bitmap thumbnail = (Bitmap) data.getExtras().get("data");
circleImageView.setImageBitmap(thumbnail);
saveImage(thumbnail);
Toast.makeText(getApplicationContext(), "Image Saved!", Toast.LENGTH_SHORT).show();
}
}
现在是存储图片的时候了
public String saveImage(Bitmap myBitmap) {
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
myBitmap.compress(Bitmap.CompressFormat.JPEG, 90, bytes);
File wallpaperDirectory = new File(Environment.getExternalStorageDirectory() + IMAGE_DIRECTORY);
if (!wallpaperDirectory.exists()) { // have the object build the directory structure, if needed.
wallpaperDirectory.mkdirs();
}
try {
File f = new File(wallpaperDirectory, Calendar.getInstance().getTimeInMillis() + ".jpg");
f.createNewFile();
FileOutputStream fo = new FileOutputStream(f);
fo.write(bytes.toByteArray());
MediaScannerConnection.scanFile(this,
new String[]{f.getPath()},
new String[]{"image/jpeg"}, null);
fo.close();
Log.d("TAG", "File Saved::--->" + f.getAbsolutePath());
return f.getAbsolutePath();
} catch (IOException e1) {
e1.printStackTrace();
}
return "";
}
请求许可
private void requestMultiplePermissions() {
Dexter.withActivity(this)
.withPermissions(
Manifest.permission.CAMERA,
Manifest.permission.WRITE_EXTERNAL_STORAGE,
Manifest.permission.READ_EXTERNAL_STORAGE)
.withListener(new MultiplePermissionsListener() {
@Override
public void onPermissionsChecked(MultiplePermissionsReport report) {
if (report.areAllPermissionsGranted()) { // check if all permissions are granted
Toast.makeText(getApplicationContext(), "All permissions are granted by user!", Toast.LENGTH_SHORT).show();
}
if (report.isAnyPermissionPermanentlyDenied()) { // check for permanent denial of any permission
// show alert dialog navigating to Settings
//openSettingsDialog();
}
}
@Override
public void onPermissionRationaleShouldBeShown(List<PermissionRequest> permissions, PermissionToken token) {
token.continuePermissionRequest();
}
}).
withErrorListener(new PermissionRequestErrorListener() {
@Override
public void onError(DexterError error) {
Toast.makeText(getApplicationContext(), "Some Error! ", Toast.LENGTH_SHORT).show();
}
})
.onSameThread()
.check();
}
下面是一个示例活动，它将启动相机应用程序，然后检索图像并显示它。
package edu.gvsu.cis.masl.camerademo;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
public class MyCameraActivity extends Activity
{
private static final int CAMERA_REQUEST = 1888;
private ImageView imageView;
private static final int MY_CAMERA_PERMISSION_CODE = 100;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
this.imageView = (ImageView)this.findViewById(R.id.imageView1);
Button photoButton = (Button) this.findViewById(R.id.button1);
photoButton.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
if (checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED)
{
requestPermissions(new String[]{Manifest.permission.CAMERA}, MY_CAMERA_PERMISSION_CODE);
}
else
{
Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, CAMERA_REQUEST);
}
}
});
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults)
{
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == MY_CAMERA_PERMISSION_CODE)
{
if (grantResults[0] == PackageManager.PERMISSION_GRANTED)
{
Toast.makeText(this, "camera permission granted", Toast.LENGTH_LONG).show();
Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, CAMERA_REQUEST);
}
else
{
Toast.makeText(this, "camera permission denied", Toast.LENGTH_LONG).show();
}
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
if (requestCode == CAMERA_REQUEST && resultCode == Activity.RESULT_OK)
{
Bitmap photo = (Bitmap) data.getExtras().get("data");
imageView.setImageBitmap(photo);
}
}
}
请注意，相机应用程序本身提供了查看/重拍图像的功能，一旦图像被接受，活动就会显示它。
下面是上面的活动使用的布局。它只是一个包含id为button1的Button和id为imageview1的ImageView的LinearLayout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Button android:id="@+id/button1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/photo"></Button>
<ImageView android:id="@+id/imageView1" android:layout_height="wrap_content" android:src="@drawable/icon" android:layout_width="wrap_content"></ImageView>
</LinearLayout>
最后一个细节，一定要加上:
<uses-feature android:name="android.hardware.camera"></uses-feature>
如果摄像头是你应用功能的可选选项。请确保在权限中将require设置为false。像这样
<uses-feature android:name="android.hardware.camera" android:required="false"></uses-feature>
到你的manifest.xml。
请使用Kotlin和Andoirdx支持来实现这个例子:
button1.setOnClickListener{
file = getPhotoFile()
val uri: Uri = FileProvider.getUriForFile(applicationContext, "com.example.foto_2.filrprovider", file!!)
captureImage.putExtra(MediaStore.EXTRA_OUTPUT, uri)
val camaraActivities: List<ResolveInfo> = applicationContext.getPackageManager().queryIntentActivities(captureImage, PackageManager.MATCH_DEFAULT_ONLY)
for (activity in camaraActivities) {
applicationContext.grantUriPermission(activity.activityInfo.packageName, uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION)
}
startActivityForResult(captureImage, REQUEST_PHOTO)
}
活动结果:
if (requestCode == REQUEST_PHOTO) {
val uri = FileProvider.getUriForFile(applicationContext, "com.example.foto_2.filrprovider", file!!)
applicationContext.revokeUriPermission(uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION)
imageView1.viewTreeObserver.addOnGlobalLayoutListener {
width = imageView1.width
height = imageView1.height
imageView1.setImageBitmap(getScaleBitmap(file!!.path , width , height))
}
if(width!=0&&height!=0){
imageView1.setImageBitmap(getScaleBitmap(file!!.path , width , height))
}else{
val size = Point()
this.windowManager.defaultDisplay.getSize(size)
imageView1.setImageBitmap(getScaleBitmap(file!!.path , size.x , size.y))
}
}
您可以在https://github.com/joelmmx/take_photo_kotlin.git上获得更多详细信息
我希望它能帮助你!
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