动态设置布局参数

Question

我正在使用CameraPreview示例API演示.我需要添加一些覆盖SurfaceView的视图(按钮等).

为此,我正在尝试设置他们的参数,但它们始终出现在屏幕的左上角.

这是代码的onCreate方法:

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);

        btnTakePhoto = new Button(this);
        btnTakePhoto.setBackgroundResource(android.R.drawable.ic_menu_camera);


        /*Set container*/
        mPreview = new Preview(this);
        setContentView(mPreview);

        /*Set button params and add it to the view*/
        RelativeLayout.LayoutParams buttonParams = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
        buttonParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
        buttonParams.addRule(RelativeLayout.CENTER_VERTICAL);
        addContentView(btnTakePhoto, buttonParams);


        numberOfCameras = Camera.getNumberOfCameras();

        CameraInfo cameraInfo = new CameraInfo();
        for (int i = 0; i < numberOfCameras; i++) {
            Camera.getCameraInfo(i, cameraInfo);
            if (cameraInfo.facing == CameraInfo.CAMERA_FACING_BACK) {
                defaultCameraId = i;
            }
        }
    }

不得不说这里的价值观

RelativeLayout.LayoutParams buttonParams = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);

如果我改变它们会更新.不改变的是包含addRule()方法的内容

Answer 1

终于解决了.在执行setContentView()和addContentView()时,我将视图放在DecorView中,这是一个FrameLayout.因此,引用RelativeLayout的LayoutParams将不起作用,因为对于FrameLayout,只有LayoutParams的通用功能才有效.

所以,首先要创建一个relativeLayout,设置params并将其设置为内容:

RelativeLayout relativeLayout = new RelativeLayout(this);
RelativeLayout.LayoutParams rlp = new RelativeLayout.LayoutParams(
                RelativeLayout.LayoutParams.MATCH_PARENT,
                RelativeLayout.LayoutParams.MATCH_PARENT);
setContentView(relativeLayout, rlp);

但是,现在,每次我想添加视图时,我都必须以这种方式将它添加到此relativeLayout:

relativeLayout.addView(View, Params);

只是这个.