Camera2不会显示使用AutoFitTextureView的预览

Question

我使用AutoFitTextureView的camera2预览出现问题。执行此代码后，布局将正常显示。相机预览不会显示。我有权使用相机。在此之前，我写道

setContentView(mTextureView)

这有效。预先谢谢你。

MainActivity

public class MainActivity extends AppCompatActivity implements TextureView.SurfaceTextureListener, ActivityCompat.OnRequestPermissionsResultCallback {
private AutoFitTextureView mTextureView;
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mTextureView = new AutoFitTextureView(this);
    mTextureView.setSurfaceTextureListener(this);
}

SurfaceTexture

 @RequiresApi(api = Build.VERSION_CODES.M)
public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
    openCamera(width, height);
}

public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
}

public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
    closeCamera();
    return true;
}

public void onSurfaceTextureUpdated(SurfaceTexture surface) {
}

AutoFitTextureView

public class AutoFitTextureView extends TextureView {

    private int mRatioWidth = 0;
    private int mRatioHeight = 0;

    public AutoFitTextureView(Context context) {
        this(context, null);
    }

    public AutoFitTextureView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public AutoFitTextureView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }


    public void setAspectRatio(int width, int height) {
        if (width < 0 || height < 0) {
            throw new IllegalArgumentException("Size cannot be negative.");
        }
        mRatioWidth = width;
        mRatioHeight = height;
        requestLayout();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        int width = MeasureSpec.getSize(widthMeasureSpec);
        int height = MeasureSpec.getSize(heightMeasureSpec);
        if (0 == mRatioWidth || 0 == mRatioHeight) {
            setMeasuredDimension(width, height);
        } else {
            if (width < height * mRatioWidth / mRatioHeight) {
                setMeasuredDimension(height * mRatioWidth / mRatioHeight, height);
            } else {
                setMeasuredDimension(width, width * mRatioHeight / mRatioWidth);
            }
        }
    }

}

布局

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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">

<FrameLayout
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#000" >

    <TextureView
        android:id="@+id/texture"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</FrameLayout>


<Button
    android:id="@+id/button_take_picture"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Button"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintStart_toStartOf="parent" />

Answer 1

布局文件中的TextureView在代码中并非自动为mTextureView。这是一个完全独立的TextureView，您可以通过常用的findViewById方法获得引用。

如果要在布局中使用AutoFitTextureView，则必须实际调用它，这需要花费更多的工作，因为必须告知布局系统有关AutoFixTextureViews的信息。

或者，您可以通过找到FrameLayout然后向其添加子级来将创建的mTextureView手动添加到布局中。

这些都是标准的Android UI创建主题，而不是特定于相机的主题，因此您应该能够找到很多资源，有关在Android上创建自定义视图或如何混合使用XML和程序化UI布局。

Answer 2

通过添加init(){}AutoFitTextureView类的方法和findViewById到MainActivity类。