Question

我正在研究一种条形码扫描仪应用程序我的条形码扫描仪和表面视图完美无缺。但是，在维护相机的宽高比时，父视图布局在较高版本的Android设备（如nexus和motog）中从底部略微削减，如第一张图片中所示。在较低版本的Android设备中我没有＆t; t面对像micromax帆布这样的问题。

这是两张图片，在第1张图片中，包含相机视图的第1个标签，以及在维护相机的纵横比期间从底部略微剪切的父视图，在第2个标签的第2张图像中，它看起来很完美。

enter image description here

这是我的cameraPreview类，

公共类CameraPreview扩展了SurfaceView实现 SurfaceHolder.Callback {

private SurfaceHolder mHolder;
private Camera mCamera;

private List<Camera.Size> mSupportedPreviewSizes;
private Camera.Size mPreviewSize;

private PreviewCallback previewCallback;
private AutoFocusCallback autoFocusCallback;

@SuppressWarnings("deprecation")
public CameraPreview(Context context, Camera camera,
        PreviewCallback previewCb, AutoFocusCallback autoFocusCb) {

    super(context);
    mCamera = camera;
    previewCallback = previewCb;
    autoFocusCallback = autoFocusCb;

    // supported preview sizes
    mSupportedPreviewSizes = mCamera.getParameters()
            .getSupportedPreviewSizes();

    // Install a SurfaceHolder.Callback so we get notified when the
    // underlying surface is created and destroyed.
    mHolder = getHolder();
    mHolder.addCallback(this);

    // deprecated setting, but required on Android versions prior to 3.0
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}

public void surfaceCreated(SurfaceHolder holder) {
    // The Surface has been created, now tell the camera where to draw the
    // preview.
    try {
        mCamera.setPreviewDisplay(holder);
    } catch (IOException e) {

        // Log.d("DBG", "Error setting camera preview: " + e.getMessage());
    }
}

public void surfaceDestroyed(SurfaceHolder holder) {
    // Camera preview released in activity
}

public void surfaceChanged(SurfaceHolder holder, int format, int width,
        int height) {
    /*
     * If your preview can change or rotate, take care of those events here.
     * Make sure to stop the preview before resizing or reformatting it.
     */
    if (mHolder.getSurface() == null) {
        // preview surface does not exist
        return;
    }

    // stop preview before making changes
    try {
        mCamera.stopPreview();
    } catch (Exception e) {
        // ignore: tried to stop a non-existent preview
    }

    // set preview size and make any resize, rotate or reformatting changes
    // here
    // start preview with new settings
    try {

        Camera.Parameters parameters = mCamera.getParameters();
        parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
        parameters.setPictureSize(mPreviewSize.width, mPreviewSize.height);
        mCamera.setParameters(parameters);
        mCamera.setDisplayOrientation(90);
        mCamera.setPreviewDisplay(mHolder);
        mCamera.startPreview();

        mCamera.setPreviewCallback(previewCallback);
        mCamera.autoFocus(autoFocusCallback);

    } catch (Exception e) {
        // Log.d("DBG", "Error starting camera preview: " + e.getMessage());
    }
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    final int width = resolveSize(getSuggestedMinimumWidth(),
            widthMeasureSpec);
    final int height = resolveSize(getSuggestedMinimumHeight(),
            heightMeasureSpec);

    if (mSupportedPreviewSizes != null) {
        mPreviewSize = getOptimalPreviewSize(mSupportedPreviewSizes, width,
                height);
    }

    float ratio;
    if (mPreviewSize.height >= mPreviewSize.width)
        ratio = (float) mPreviewSize.height / (float) mPreviewSize.width;
    else
        ratio = (float) mPreviewSize.width / (float) mPreviewSize.height;

    // One of these methods should be used, second method squishes preview
    // slightly
    setMeasuredDimension(width, (int) (width * ratio));
    // setMeasuredDimension((int) (width * ratio), height);
}

private Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int w,
        int h) {
    final double ASPECT_TOLERANCE = 0.1;
    double targetRatio = (double) h / w;

    if (sizes == null)
        return null;

    Camera.Size optimalSize = null;
    double minDiff = Double.MAX_VALUE;

    int targetHeight = h;

    for (Camera.Size size : sizes) {
        double ratio = (double) size.height / size.width;
        if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE)
            continue;

        if (Math.abs(size.height - targetHeight) < minDiff) {
            optimalSize = size;
            minDiff = Math.abs(size.height - targetHeight);
        }
    }

    if (optimalSize == null) {
        minDiff = Double.MAX_VALUE;
        for (Camera.Size size : sizes) {
            if (Math.abs(size.height - targetHeight) < minDiff) {
                optimalSize = size;
                minDiff = Math.abs(size.height - targetHeight);
            }
        }
    }

    return optimalSize;
}

}

任何帮助将不胜感激。

Answer 1

最后，我找到了一点解决方案，
我仍然没有得到真正的问题，但我只是为我的框架布局设置填充，如下所示，我在添加表面视图，它解决了我的问题。

android:padding="0.2dp"

我的framelayout如下所示，我正在添加表面视图，

    <FrameLayout
        android:id="@+id/layout_frameScanner"
        android:layout_width="match_parent"
        android:layout_height="250dp"
        android:layout_centerInParent="true"
        android:background="@color/color_black"
        android:padding="0.2dp" >
    </FrameLayout>

自定义相机与Android中的表面视图问题

1 个答案: