使用intent拍照

photoUri = FileProvider.getUriForFile( this, "${packageName}.fileprovider",
// 与 manifest authorities 一致 photoFile ) ```
</Tab>
<Tab label="Java">
```java File photoFile = File.createTempFile("IMG_", ".jpg", getCacheDir());
Uri photoUri = FileProvider.getUriForFile( this, getPackageName() +
".fileprovider", photoFile ); ```
</Tab>
</CodeTabs>
 
### 处理拍照结果：Activity Result API
 
旧写法 `onActivityResult` 已废弃。现代写法用 `registerForActivityResult`：
 
<CodeTabs>
<Tab label="Kotlin">
```kotlin
private lateinit var photoUri: Uri
 
private val takePictureLauncher = registerForActivityResult(
ActivityResultContracts.TakePicture()
) { success ->
if (success) {
// 照片已写入 photoUri 指向的文件
binding.imageView.setImageURI(photoUri)
}
}
 
fun takePhoto() {
val photoFile = File.createTempFile("IMG\_", ".jpg", cacheDir)
photoUri = FileProvider.getUriForFile(
this, "${packageName}.fileprovider", photoFile
)
takePictureLauncher.launch(photoUri)
}
 

private Uri photoUri;
 
private final ActivityResultLauncher<Uri> takePictureLauncher =
    registerForActivityResult(new ActivityResultContracts.TakePicture(), success -> {
        if (success) {
            imageView.setImageURI(photoUri);
        }
    });
 
public void takePhoto() {
    File photoFile = File.createTempFile("IMG_", ".jpg", getCacheDir());
    photoUri = FileProvider.getUriForFile(
        this, getPackageName() + ".fileprovider", photoFile
    );
    takePictureLauncher.launch(photoUri);
}

// 方式 A：缩略图（不推荐用于展示大图）
private val captureLauncher = registerForActivityResult(
    ActivityResultContracts.StartActivityForResult()
) { result ->
    val thumbnail = result.data?.extras?.get("data") as? Bitmap
    binding.imageView.setImageBitmap(thumbnail)  // 模糊的小图
}
 
// 方式 B：全分辨率（推荐）
private val takePictureLauncher = registerForActivityResult(
ActivityResultContracts.TakePicture()
) { success ->
if (success) {
// 用 BitmapFactory 加载并缩放显示
val bitmap = BitmapFactory.decodeFile(photoFile.absolutePath)
binding.imageView.setImageBitmap(bitmap)
}
}
 

// 方式 B：全分辨率（推荐）
private final ActivityResultLauncher<Uri> takePictureLauncher =
    registerForActivityResult(new ActivityResultContracts.TakePicture(), success -> {
        if (success) {
            Bitmap bitmap = BitmapFactory.decodeFile(photoFile.getAbsolutePath());
            imageView.setImageBitmap(bitmap);
        }
    });

class PhotoActivity : AppCompatActivity() {
    private lateinit var binding: ActivityPhotoBinding
    private lateinit var photoFile: File
    private lateinit var photoUri: Uri
 
    private val takePictureLauncher = registerForActivityResult(
        ActivityResultContracts.TakePicture()
    ) { success ->
        if (success) {
            binding.imageView.setImageURI(photoUri)
        } else {
            Toast.makeText(this, "拍照取消", Toast.LENGTH_SHORT).show()
        }
    }
 
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityPhotoBinding.inflate(layoutInflater)
        setContentView(binding.root)
        binding.btnTakePhoto.setOnClickListener { takePhoto() }
    }
 
    private fun takePhoto() {
        photoFile = File.createTempFile("IMG_", ".jpg", cacheDir)
        photoUri = FileProvider.getUriForFile(
            this, "${packageName}.fileprovider", photoFile
        )
        takePictureLauncher.launch(photoUri)
    }
 
}
 

public class PhotoActivity extends AppCompatActivity {
    private ActivityPhotoBinding binding;
    private File photoFile;
    private Uri photoUri;
 
    private final ActivityResultLauncher<Uri> takePictureLauncher =
        registerForActivityResult(new ActivityResultContracts.TakePicture(), success -> {
            if (success) {
                binding.imageView.setImageURI(photoUri);
            } else {
                Toast.makeText(this, "拍照取消", Toast.LENGTH_SHORT).show();
            }
        });
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityPhotoBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());
        binding.btnTakePhoto.setOnClickListener(v -> takePhoto());
    }
 
    private void takePhoto() {
        try {
            photoFile = File.createTempFile("IMG_", ".jpg", getCacheDir());
            photoUri = FileProvider.getUriForFile(
                this, getPackageName() + ".fileprovider", photoFile
            );
            takePictureLauncher.launch(photoUri);
        } catch (IOException e) {
            Toast.makeText(this, "无法创建临时文件", Toast.LENGTH_SHORT).show();
        }
    }
}

val captureIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE).apply {
    putExtra(MediaStore.EXTRA_OUTPUT, photoUri)
    addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION)
}
startActivityForResult(captureIntent, REQUEST_CODE)  // 旧 API，已废弃

Intent captureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
captureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoUri);
captureIntent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
startActivityForResult(captureIntent, REQUEST_CODE);  // 旧 API，已废弃