Question

我试图在相机预览上绘制一个矩形叠加层。我在FrameView中获得了叠加层，onDraw（）被成功调用，但矩形从不显示。我已经四处搜索并尝试了不同的解决方案，但到目前为止还没有一个对我有效。

这就是我对FrameView的看法

public class FrameView extends View {
    private Paint mFramePaint = null;
    private final String TAG = "FrameView";

    public FrameView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mFramePaint = new Paint();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        mFramePaint.setStyle(Paint.Style.FILL);
        mFramePaint.setColor(Color.GREEN);

        Rect drawRect = new Rect(300,300,300,300);

        canvas.drawRect(drawRect, mFramePaint);
    }
}

这是我的相机预览活动的xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.eyesee.CameraPreviewActivity" 
    android:id="@+id/camera_preview">

    <com.example.eyesee.FrameView
        android:id="@+id/frame_view"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent" />
</RelativeLayout>

这是我的相机预览活动中用于附加相机预览的代码片段

private Camera mCamera;
private CameraPreview mPreview;
private final String TAG = "CameraPreviewActivity";

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

    mCamera = MainActivity.getCameraInstance();

    mPreview = new CameraPreview(this, mCamera);
    RelativeLayout preview = (RelativeLayout)   findViewById(R.id.camera_preview);
    preview.addView(mPreview);
}

在相机预览上绘制矩形时遇到问题

0 个答案: