Android拍照保存

旧城等待， 2022-09-10 06:27 242阅读 0赞

1、拍照是在安卓开发中常用到的一个功能，所以需要熟练掌握

2、实现的功能是：拍照、保存到指定文件夹、照片可以命名

3、先获得读取文件夹的权限：

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

List<String> permissionList = new ArrayList<>();
    if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.
            permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
        permissionList.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
    }
    if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.
            permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
        permissionList.add(Manifest.permission.CAMERA);
    }
    if (!permissionList.isEmpty()) {
        String[] permissions = permissionList.toArray(new String[permissionList.size()]);
        ActivityCompat.requestPermissions(MainActivity.this, permissions, 1);
    }

4、新建**FileProvider**，不然会报错Unable to get provider androidx.core.content.FileProvider: java.lang.IllegalArgumentException: Missing android.support.FILE\_PROVIDER\_PATHS meta-data，先建一个**xml文件夹**：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA5LmL5LmO6ICF5Lmf5ZOm_size_7_color_FFFFFF_t_70_g_se_x_16][]

<?xml version="1.0" encoding="utf-8"?>
    <paths>
        <external-path
            name="my_images"
            path="."/>
    </paths>

然后写入元数据：

5、完整代码：

<?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="com.example.myapplication">
    
        
        <uses-permission android:name="android.permission.CAMERA" />
        <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    
        <application
            android:allowBackup="true"
            android:icon="@mipmap/ic_launcher"
            android:label="@string/app_name"
            android:roundIcon="@mipmap/ic_launcher_round"
            android:supportsRtl="true"
            android:theme="@style/Theme.MyApplication">
    
            <provider
                android:name="androidx.core.content.FileProvider"
                android:authorities="com.example.myapplication.fileprovider"
                android:exported="false"
                android:grantUriPermissions="true">
                <meta-data
                    android:name="android.support.FILE_PROVIDER_PATHS"
                    android:resource="@xml/file_paths" />
            </provider>
    
            <activity android:name=".MainActivity">
                <intent-filter>
                    <action android:name="android.intent.action.MAIN" />
    
                    <category android:name="android.intent.category.LAUNCHER" />
                </intent-filter>
            </activity>
        </application>
    
    </manifest>

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        tools:context=".MainActivity">
    
        <Button
            android:id="@+id/button"
            android:text="拍照"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>
    
        <ImageView
            android:id="@+id/imageView"
            android:layout_width="match_parent"
            android:layout_height="match_parent" />
    
    </LinearLayout>

package com.example.myapplication;
    
    import androidx.appcompat.app.AppCompatActivity;
    import androidx.core.app.ActivityCompat;
    import androidx.core.content.ContextCompat;
    import androidx.core.content.FileProvider;
    
    import android.Manifest;
    import android.annotation.SuppressLint;
    import android.content.Intent;
    import android.content.pm.PackageManager;
    import android.graphics.Bitmap;
    import android.graphics.BitmapFactory;
    import android.net.Uri;
    import android.os.Build;
    import android.os.Bundle;
    import android.os.Environment;
    import android.provider.MediaStore;
    import android.view.View;
    import android.widget.Button;
    import android.widget.ImageView;
    import android.widget.Toast;
    
    import java.io.File;
    import java.io.FileNotFoundException;
    import java.io.IOException;
    import java.text.SimpleDateFormat;
    import java.util.ArrayList;
    import java.util.Date;
    import java.util.List;
    
    public class MainActivity extends AppCompatActivity {
        private String currentPhotoPath;
        private ImageView imageView;
        static final int REQUEST_TAKE_PHOTO = 1;
    
        private void dispatchTakePictureIntent() {
            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;
                photoFile = createImageFile();
                // Continue only if the File was successfully created
                if (photoFile != null) {
                    Uri photoURI;
                    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                        /*7.0以上要通过FileProvider将File转化为Uri*/
                        photoURI = FileProvider.getUriForFile(this, "com.example.myapplication.fileprovider", photoFile);
                    } else {
                        /*7.0以下则直接使用Uri的fromFile方法将File转化为Uri*/
                        photoURI = Uri.fromFile(photoFile);
                    }
                    takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
                    startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
                }
            }
        }
    
        private File createImageFile() {
            // Create an image file name
            @SuppressLint("SimpleDateFormat") String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
            String imageFileName = "JPEG_" + timeStamp;
            File storageDir = new File(Environment.getExternalStorageDirectory(), "AAAAA");
            if (!storageDir.exists())
                storageDir.mkdirs();
            File currentImageFile = new File(storageDir, imageFileName + ".jpg");
            if (!currentImageFile.exists()) {
                try {
                    currentImageFile.createNewFile();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            // Save a file: path for use with ACTION_VIEW intents
            currentPhotoPath = currentImageFile.getAbsolutePath();
            return currentImageFile;
        }
    
        //添加到相册
        private void galleryAddPic() {
            Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
            File f = new File(currentPhotoPath);
            Uri contentUri = Uri.fromFile(f);
            mediaScanIntent.setData(contentUri);
            this.sendBroadcast(mediaScanIntent);
        }
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            imageView = findViewById(R.id.imageView);
    
            Button button = findViewById(R.id.button);
            button.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    dispatchTakePictureIntent();
                }
            });
    
            List<String> permissionList = new ArrayList<>();
            if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.
                    permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                permissionList.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
            }
            if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.
                    permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                permissionList.add(Manifest.permission.CAMERA);
            }
            if (!permissionList.isEmpty()) {
                String[] permissions = permissionList.toArray(new String[permissionList.size()]);
                ActivityCompat.requestPermissions(MainActivity.this, permissions, 1);
            }
        }
    
        //返回结果
        @Override
        protected void onActivityResult(int requestCode, int resultCode, Intent data) {
            if (requestCode == REQUEST_TAKE_PHOTO && resultCode == RESULT_OK) {
                galleryAddPic();
                //如果写入本地//takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);data就会变成null
                if (data != null) {
                    Bundle bundle = data.getExtras();
                    Bitmap bitmap = (Bitmap) bundle.get("data");
                    imageView.setImageBitmap(bitmap);
                } else {
                    Toast.makeText(MainActivity.this, "data is null", Toast.LENGTH_LONG).show();
                    //本地读
                    File file = new File(currentPhotoPath);
                    Uri uri = Uri.fromFile(file);
                    try {
                        Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(uri));
                        imageView.setImageBitmap(bitmap);
    
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    }
                }
    
            }
    
            super.onActivityResult(requestCode, resultCode, data);
    
        }
    }

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