扩展类时错误膨胀 [英] Error inflating when extending a class

问题描述

我正在尝试创建一个扩展 SurfaceView 的自定义视图 GhostSurfaceCameraView.这是我的类定义文件

I'm trying to create a custom view GhostSurfaceCameraView that extends SurfaceView. Here's my class definition file

GhostSurfaceCameraView.java:

public class GhostSurfaceCameraView extends SurfaceView implements SurfaceHolder.Callback {
    SurfaceHolder mHolder;
    Camera mCamera;

    GhostSurfaceCameraView(Context context) {
        super(context);

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

    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, acquire the camera and tell it where to draw.
        mCamera = Camera.open();
        try {
            mCamera.setPreviewDisplay(holder);
        } catch (IOException exception) {
            mCamera.release();
            mCamera = null;
            // TODO: add more exception handling logic here
        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // Surface will be destroyed when we return, so stop the preview.
        // Because the CameraDevice object is not a shared resource, it's very
        // important to release it when the activity is paused.
        mCamera.stopPreview();
        mCamera.release();
        mCamera = null;
    }   

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // Now that the size is known, set up the camera parameters and begin
        // the preview.
        Camera.Parameters parameters = mCamera.getParameters();
        parameters.setPreviewSize(w, h);
        parameters.set("orientation", "portrait");
        // parameters.setRotation(90); // API 5+
        mCamera.setParameters(parameters);
        mCamera.startPreview();
    }
}

这是在我的 ghostviewscreen.xml 中:

And this is in my ghostviewscreen.xml:

<com.alpenglow.androcap.GhostSurfaceCameraView android:id="@+id/ghostview_cameraview"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"/>

现在在我所做的活动中:

Now in the activity I made:

protected void onCreate(Bundle savedInstanceState) {
    try {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.ghostviewscreen);
    }
}

当 setContentView() 被调用时，抛出异常:

When setContentView() gets called, an exception is thrown:

Binary XML file 09-17 22:47:01.958: ERROR/ERROR(337):
ERROR IN CODE:
android.view.InflateException: Binary
XML file line #14: Error inflating
class
com.alpenglow.androcap.GhostSurfaceCameraView

谁能告诉我为什么会出现这个错误?谢谢.

Can anyone tell me why I get this error? Thanks.

推荐答案

我想我知道为什么这不起作用了.当我应该为两个参数 'Context, AttributeSet' 情况提供构造函数时，我只为一个参数 'context' 的情况提供了一个构造函数.我还需要为构造函数提供公共访问权限.这是我的修复:

I think I figured out why this wasn't working. I was only providing a constructor for the case of one parameter 'context' when I should have provided a constructor for the two parameter 'Context, AttributeSet' case. I also needed to give the constructor(s) public access. Here's my fix:

public class GhostSurfaceCameraView extends SurfaceView implements SurfaceHolder.Callback {
        SurfaceHolder mHolder;
        Camera mCamera;

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

这篇关于扩展类时错误膨胀的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！