提及“方法”不明确

Question

当调用Builder（）时，我收到错误消息：

对“ Builder”的引用不明确，“ androidx.camera.core.impl.UseCaseConfig.Builder”和“ androidx.camera.core.impl.ImageOutputConfig.Builder”都匹配

错误是在startCamera（）函数中产生的。我如何确保编译器知道使用UseCaseConfig选项？感谢您的帮助，谢谢您的时间和帮助。

package com.example.atlas2.Activities.Login.UserCreation.ProfilePhotoCamerax;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.camera.core.impl.PreviewConfig;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import android.content.pm.PackageManager;
import android.graphics.Matrix;
import android.os.Bundle;
import android.util.Rational;
import android.util.Size;
import android.view.Surface;
import android.view.TextureView;
import android.widget.Toast;

import com.example.atlas2.R;

public class ProfilePhotoActivityX extends AppCompatActivity {


    private int REQUEST_CODE_PERMISSIONS = 101;
    private final String[] REQUIRED_PERMISSIONS = new String[]{"android.permission.CAMERA", 
                                                  "android.permission.WRITE_EXTERNAL_STORAGE"};
    TextureView textureView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_profile_photo_x);

        textureView = findViewById(R.id.view_finder);

        if(allPermissionsGranted()){
            startCamera(); //start camera if permission has been granted by user
        } else{
            ActivityCompat.requestPermissions(this, REQUIRED_PERMISSIONS, REQUEST_CODE_PERMISSIONS);
        }
    }

    private void startCamera() {

        Rational aspectRatio = new Rational(textureView.getWidth(), textureView.getHeight());
        Size screen = new Size(textureView.getWidth(), textureView.getHeight());

        PreviewConfig pConfig = new PreviewConfig.Builder<>();

    }

    private void updateTransform(){
        Matrix mx = new Matrix();
        float w = textureView.getMeasuredWidth();
        float h = textureView.getMeasuredHeight();

        float cX = w / 2f;
        float cY = h / 2f;

        int rotationDgr;
        int rotation = (int)textureView.getRotation();

        switch(rotation){
            case Surface.ROTATION_0:
                rotationDgr = 0;
                break;
            case Surface.ROTATION_90:
                rotationDgr = 90;
                break;
            case Surface.ROTATION_180:
                rotationDgr = 180;
                break;
            case Surface.ROTATION_270:
                rotationDgr = 270;
                break;
            default:
                return;
        }

        mx.postRotate((float)rotationDgr, cX, cY);
        textureView.setTransform(mx);
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull 
                                           int[] grantResults) {

        if(requestCode == REQUEST_CODE_PERMISSIONS){
            if(allPermissionsGranted()){
                startCamera();
            } else{
                Toast.makeText(this, "Permissions not granted by the user.", 
                               Toast.LENGTH_SHORT).show();
                finish();
            }
        }
    }

    private boolean allPermissionsGranted(){

        for(String permission : REQUIRED_PERMISSIONS){
            if(ContextCompat.checkSelfPermission(this, permission) != 
               PackageManager.PERMISSION_GRANTED){
                return false;
            }
        }
        return true;
    }
}

Answer 1

首先-您正在使用哪个版本的CameraX？最新的（在撰写本文时）是alpha09（核心），您应在其中构建预览，如下所示：

Preview preview = new Preview.Builder().build();

然后，您可以轻松地在builder中使用任何设置方法进行预览配置。 google docs尚未完全更新为最新版本，因此您可以使用forum寻求帮助。