Android studio调用相机拍照并显示到ImageView中

好的，下面是实现的步骤：

1.在AndroidManifest.xml文件中添加相机权限

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

2.在布局文件中添加ImageView和Button控件

<ImageView
    android:id="@+id/imageView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:src="@drawable/ic_image_placeholder" />

<Button
    android:id="@+id/buttonCapture"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Capture" />

3.在Activity中获取相机权限，并设置Button的点击事件

public class MainActivity extends AppCompatActivity {
    private static final int REQUEST_IMAGE_CAPTURE = 1;
    private ImageView imageView;

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

        imageView = findViewById(R.id.imageView);

        Button buttonCapture = findViewById(R.id.buttonCapture);
        buttonCapture.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                    requestPermissions(new String[]{Manifest.permission.CAMERA}, REQUEST_IMAGE_CAPTURE);
                } else {
                    dispatchTakePictureIntent();
                }
            }
        });
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        if (requestCode == REQUEST_IMAGE_CAPTURE) {
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                dispatchTakePictureIntent();
            } else {
                Toast.makeText(this, "Camera permission denied", Toast.LENGTH_SHORT).show();
            }
        }
    }

    private void dispatchTakePictureIntent() {
        Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
            startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK) {
            Bundle extras = data.getExtras();
            Bitmap imageBitmap = (Bitmap) extras.get("data");
            imageView.setImageBitmap(imageBitmap);
        }
    }
}

4.运行程序，点击按钮将会打开相机拍照，照片将会显示在ImageView中。

注意：以上代码仅为演示如何使用相机拍照并显示到ImageView中，实际使用中还需要处理异常情况和兼容性问题。