实现流程
前提
TextureView.SurfaceTextureListener是一个接口，用于监听TextureView中的SurfaceTexture的状态更改。在使用相机时，您可以使用TextureView来显示相机预览。通过实现SurfaceTextureListener接口，您可以在SurfaceTexture准备好时开始相机预览，并在SurfaceTexture销毁时停止预览。
注意: 必须是在 onSurfaceTextureAvailable 准备好后，才可开启相机
- 接口如下：
- （案例代码中是以implements TextureView.SurfaceTextureListener这种形式实现）
TextureView textureView = findViewById(R.id.texture_view);
textureView.setSurfaceTextureListener(new TextureView.SurfaceTextureListener() {
@Override
public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int width, int height) {
// Open camera and start preview
}
@Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surfaceTexture, int width, int height) {
// Handle texture size change if necessary
}
@Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surfaceTexture) {
// Stop camera preview and release camera
return true;
}
@Override
public void onSurfaceTextureUpdated(SurfaceTexture surfaceTexture) {
// Handle surface texture update if necessary
}
});
一、获取CameraManager实例
CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
二、获取可用的相机列表
String[] cameraIds = manager.getCameraIdList();
三、选择一个相机并打开它
String cameraId = cameraIds[0];
manager.openCamera(cameraId, new CameraDevice.StateCallback() {
@Override
public void onOpened(CameraDevice camera) {
// 相机已经打开，可以进行后续操作
}
@Override
public void onDisconnected(CameraDevice camera) {
// 相机断开连接，需要释放资源
camera.close();
}
@Override
public void onError(CameraDevice camera, int error) {
// 相机打开出错，需要释放资源
camera.close();
}
}, null);
四、创建一个CaptureRequest.Builder对象
CaptureRequest.Builder builder = camera.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
五、设置CaptureRequest.Builder对象的参数
builder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
六、创建一个CaptureSession对象
camera.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(CameraCaptureSession session) {
// CaptureSession已经创建，可以进行后续操作
}
@Override
public void onConfigureFailed(CameraCaptureSession session) {
// CaptureSession创建失败，需要释放资源
camera.close();
}
}, null);
七、开始预览
session.setRepeatingRequest(builder.build(), null, null);
代码示例
必须是动态获取权限后才能开启预览
- xml布局
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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="match_parent"
tools:context=".MainActivity">
<TextureView
android:id="@+id/texture_view"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
- 处理
public class MainActivity extends AppCompatActivity implements TextureView.SurfaceTextureListener{
private String[] cameraIds;
private String cameraId;
private CameraManager cameraManager;//从系统服务中获取相机管理器
private TextureView textureView;
private CameraDevice mCameraDevice;
private CameraCaptureSession cameraCaptureSession;
private CaptureRequest.Builder builder = null;
private static final int ACTION_REQUEST_PERMISSIONS = 0x001;
/**
* 所需的所有权限信息
*/
private static final String[] NEEDED_PERMISSIONS = new String[]{
Manifest.permission.CAMERA,//相机
};
@SuppressLint({"MissingPermission", "MissingInflatedId"})
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//权限检查
if (!checkPermissions(NEEDED_PERMISSIONS)) {
ActivityCompat.requestPermissions(this, NEEDED_PERMISSIONS,
ACTION_REQUEST_PERMISSIONS);
}
textureView=findViewById(R.id.texture_view);
textureView.setSurfaceTextureListener(this);//设置布局
}
/**
* 权限检查
* @param neededPermissions 需要的权限
* @return 是否全部被允许
*/
protected boolean checkPermissions(String[] neededPermissions) {
if (neededPermissions == null || neededPermissions.length == 0) {
return true;
}
boolean allGranted = true;
for (String neededPermission : neededPermissions) {
allGranted &= ContextCompat.checkSelfPermission(this, neededPermission) == PackageManager.PERMISSION_GRANTED;
}
return allGranted;
}
@Override
public void onSurfaceTextureAvailable(@NonNull SurfaceTexture surfaceTexture, int i, int i1) {
//布局初始化完成,打开相机
if (checkPermissions(NEEDED_PERMISSIONS)) {
openCamera2();
}
}
@SuppressLint("MissingPermission")
private void openCamera2(){
//一、获取cameraManager
cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
try {
cameraIds = cameraManager.getCameraIdList();//获取摄像机id的集合
cameraId = cameraIds[0];
cameraManager.openCamera(cameraId,callback,null);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
CameraDevice.StateCallback callback=new CameraDevice.StateCallback() {
@Override
public void onOpened(@NonNull CameraDevice cameraDevice) {
mCameraDevice = cameraDevice;
createCameraPreviewSession();
}
@Override
public void onDisconnected(@NonNull CameraDevice cameraDevice) {
}
@Override
public void onError(@NonNull CameraDevice cameraDevice, int i) {
}
};
private void createCameraPreviewSession() {
try {
SurfaceTexture surfaceTexture = textureView.getSurfaceTexture();
// surfaceTexture.setDefaultBufferSize(textureView.getWidth(), textureView.getHeight());
surfaceTexture.setDefaultBufferSize(640, 480);
// surfaceTexture.setDefaultBufferSize(480,640 );
Surface previewSurface = new Surface(surfaceTexture);
builder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
builder.addTarget(previewSurface);
mCameraDevice.createCaptureSession(Arrays.asList(previewSurface), new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(CameraCaptureSession session) {
cameraCaptureSession = session;
try {
cameraCaptureSession.setRepeatingRequest(builder.build(), null, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
@Override
public void onConfigureFailed(CameraCaptureSession session) {
Toast.makeText(MainActivity.this, "Failed to create camera capture session", Toast.LENGTH_SHORT).show();
}
}, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode) {
case ACTION_REQUEST_PERMISSIONS: {
// 如果请求被取消，结果数组将为空
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// 授权成功，执行相关操作
//打开相机
openCamera2();
} else {
// 授权失败，禁用相关功能或显示提示信息
}
return;
}
// 处理其他权限请求
}
}
@Override
public void onSurfaceTextureSizeChanged(@NonNull SurfaceTexture surfaceTexture, int i, int i1) {
}
@Override
public boolean onSurfaceTextureDestroyed(@NonNull SurfaceTexture surfaceTexture) {
return false;
}
@Override
public void onSurfaceTextureUpdated(@NonNull SurfaceTexture surfaceTexture) {
}
@Override
protected void onResume() {
super.onResume();
}
}
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