Android学习之调用相机和相册_"imageuri= fileprovider.geturiforfile(tuxiang.this

调用摄像头拍照

修改布局文件中代码：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:orientation="vertical"
              android:layout_width="match_parent"
              android:layout_height="match_parent">
    <Button
        android:id="@+id/take_photo"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Take Photo"/>    //用来打开摄像头进行拍照
 
    <ImageView
        android:id="@+id/picture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"/>   //将拍到的图片显示出来
</LinearLayout>

编写调用摄像头的具体逻辑。修改活动文件：

public class MainActivity extends AppCompatActivity {
    public static final int TAKE_PHOTO = 1;
    private ImageView picture;
    private Uri imageUri;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button takePhoto = (Button) findViewById(R.id.take_photo);
        picture = (ImageView) findViewById(R.id.picture);
        takePhoto.setOnClickListener(new View.OnClickListener(){
            @Override
            public  void onClick(View v){
                File outputImage = new File(getExternalCacheDir(),"output_image.jpg");   //创建了一个File对象，用于存放摄像头拍下的图片，并将它保存在SD卡的应用缓存目录下，用getExternalCacheDir（）得到目录
                try{
                    if(outputImage.exists()){
                        outputImage.delete();
                    }
                    outputImage.createNewFile();
                }catch (IOException e) {
                    e.printStackTrace();
                }
                if(Build.VERSION.SDK_INT>=24){   //若设备系统版本低于Android7.0，就调用Uri的fromFile（）将File对象转换成Uri对象(表示着图片的本地真实路径)
                    imageUri = FileProvider.getUriForFile(MainActivity.this,"com/example.cameraalbumtest.fileprovider",outputImage);//否则就调用FileProvider的getUriForFile（）
                }else{
                    imageUri = Uri.fromFile(outputImage);   方法将File对象转换成一个封装过的Uri对象
                }
                Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");//将这个Intent的action指定为android.media.action.IMAGE_CAPTURE
                intent.putExtra(MediaStore.EXTRA_OUTPUT,imageUri);//置顶图片的输出地址
                startActivityForResult(intent,RAKE_PHOTO);
            }
        });
    }
    @Override
    protected void onActivityResult(int requestCode,int resultCode, Intent data){  //用startActivityForResult（）启动活动会有结果返回到此方法中
        switch (requestCode){
            case TAKE_PHOTO:
                if(resultCode == RESULT_OK){
                    try{
                        //将拍摄的照片显示出来
                        Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream((imageUri));
                        picture.setImageBitmap(bitmap);
                    }catch (FileNotFoundException e){
                        e.printStackTrace();
                    }
                }
                break;
            default:
                break;
        }
    }
}

在AndroidMainfest.xml中对内容提供器（FileProvider）进行注册：

    <provider
            android:authorities="com.example.cameraalbumtest.fileprovider"  //必须和干菜FileProvider.getUriForFile（）方法中第二个参数一致
            android:name="android.support.v4.content.FileProvider"  //此属性值是固定的
            android:exported="false"
            android:grantUriPermissions="true">
            <meta-data              //用<meta-data>来指定Uri的共享路径，并引用了一个@xml/file_path资源（下面我们来创建）
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/file_paths"/>
        </provider>

创建上面说的@xml/file_path资源

<?xml version="1.0" encoding="utf-8" ?>
<paths xmlns:andriod="http://schemas.android.com/apk/res/android">
    <enternal-path name="my_images" path=""/>    //用来指定Uri共享，name属性值可以随便填，path属性的指标是共享的具体路径，此处为空表示共
</paths>                                         //享整个SD卡

在Android4.4之前，需要声明权限：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.example.cameraalbumtest">
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

从相册中选择照片

在上面的基础上在布局文件中添加：

   <Button
        android:id="@+id/choose_from_album"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text=""Choose From Album/>

然后修改MainActivity文件中代码，加入从相册选择照片的逻辑：（红色为新增）

public class MainActivity extends AppCompatActivity {
    public static final int TAKE_PHOTO = 1;
    private ImageView picture;
    private Uri imageUri;
    public static final int CHOOSE_PHOTO = 2;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button takePhoto = (Button) findViewById(R.id.take_photo);
        Button chooseFromAlbum = (Button) findViewById(R.id.choose_from_album);
        picture = (ImageView) findViewById(R.id.picture);
        takePhoto.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                File outputImage = new File(getExternalCacheDir(), "output_image.jpg");
                try {
                    if (outputImage.exists()) {
                        outputImage.delete();
                    }
                    outputImage.createNewFile();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                if (Build.VERSION.SDK_INT >= 24) {
                    imageUri = FileProvider.getUriForFile(MainActivity.this, "com/example.cameraalbumtest.fileprovider", outputImage);
                } else {
                    imageUri = Uri.fromFile(outputImage);
                }
                Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
                intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri);
                startActivityForResult(intent, RAKE_PHOTO);
            }
        });
        chooseFromAlbum.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {   //申请权限
                    ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
                } else {
                    openAlbum();
                }
            }
        });
    }
 
    private void openAlbum() {
        Intent intent = new Intent("android.intent.action.GET_CONTENT");//将他的action指定为“”中的
        intent.setType("image/*");
        startActivityForResult(intent, CHOOSE_PHOTO);  //打开相册。第二个参数值为CHOOSE_PHOTO，
    }   //当从相册选择完图片回到onActivityResult方法时，就会进入CHOOSE_PHOTO的case来处理图片
 
    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        switch (requestCode) {
            case 1:
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    openAlbum();
                } else {
                    Toast.makeText(this, "You denied the permission", Toast.LENGTH_SHORT).show();
                }
                break;
            default:
        }
    }
    @Override
    protected void onActivityResult(int requestCode,int resultCode, Intent data){
        switch (requestCode){
            case TAKE_PHOTO:
                if(resultCode == RESULT_OK){
                    try{
                        //将拍摄的照片显示出来
                        Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(imageUri));
                        picture.setImageBitmap(bitmap);
                    }catch (FileNotFoundException e){
                        e.printStackTrace();
                    }
                }
                break;
            case CHOOSE_PHOTO:
                if(resultCode == RESULT_OK) {
                    if (Build.VERSION.SDK_INT >= 19) {  //进行版本判断
                        handleImageOnKitKat(data);
                    } else {
                        handleImageBeforeKitKat(data);
                    }
                }
                break;
            default:
                break;
        }
    }
    @Target(19)
private void handleImageOnKitKat(Intent data) {   //如何解析这个封装过的Uri
        String imagePath = null;
        Uri uri = data.getData();
        if( DocumentsContract.isDocumentUri(this,Uri)){
            String docId = DocumentsContract.getDocumentId(uri);
            if ("com.android.providers.media.documents".equals(uri.getAuthority())){
                String id = docId.split(":")[1];
                String selection = MediaStore.Images.Media._ID + "=" + id;
                imagePath = getImagePath(MediaStore.Inages.Media.EXTERNAL_CONTENT_URI,selection);
            }else if("com.android.providers.downloads.documents"。equals(uri.getAuthority())){
                Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"),Long.valueOf(docId));
                imagePath = getImagePath(contentUri, null);}
        }else if ("content".equalsIgnoreCase(uri.getScheme())){
                imagePath = getImagePath(uri,null);
        }else if ("file".equalsIgnoreCase(uri.getScheme())){
            imagePath = uri.getPath();
        }
        displayImage(imagePath);
    }
    private void handleImageBeforeKitKat(Intent data) {
        Uri uri = data.getData();
        String imagePath = getImagePath(rui,null);
        displayImage(imagePath);
    }
 
    private String getImagePath(Uri uri,String selection){
        String path = null;
        Cursor cursor = getContentResolver().query(uri,null,selection,null,null);
        if(cursor != null){
            if(cursor.moveToFirst()){
                path = cursor.getString(cursor.getColumnIndex(MediaStore.Images.Media.DATA));
            }
            cursor.close();
        }
        return path;
    }
    private void displayImage(String imagePath){
        if(imagePath != null){
            Bitmap bitmap = BitmapFactory.decodeFile(imagePath);
            picture.setImageBitmap(bitmap);
        }else{
            Toast.makeText(this,"failed to get image",Toast.LENGTH_SHORT).show();
        }
    }
}

应该有错，不过可以根据报错修改