android处理Back键Home键和Menu键事件(转)

 @Override
    public boolean onKeyDown(int keyCode, KeyEvent event)
    {
        if(keyCode == KeyEvent.KEYCODE_BACK)
        { //监控/拦截/屏蔽返回键
            dialog();

            return false; 

        } else if(keyCode == KeyEvent.KEYCODE_MENU)
        {
            if(isShowButton)
            {
                rly.setVisibility(View.VISIBLE);
                isShowButton = false;

            }else
            {
                rly.setVisibility(View.GONE);
                isShowButton = true;
            }

            return false;

        } else if(keyCode == KeyEvent.KEYCODE_HOME)
        {
            //由于Home键为系统键，此处不能捕获，需要重写onAttachedToWindow()

            return false;
        }
        return super.onKeyDown(keyCode, event);
     }

    protected void dialog()
    {
        AlertDialog.Builder builder = new Builder(WebActivity.this);
        builder.setMessage("确定要退出吗?");
        builder.setTitle("提示");
        builder.setPositiveButton("确认",
        new android.content.DialogInterface.OnClickListener()
        {
            public void onClick(DialogInterface dialog, int which)
            {
                dialog.dismiss();
                WebActivity.this.finish();
            }
        }); 

        builder.setNegativeButton("取消",
        new android.content.DialogInterface.OnClickListener()
        {
            public void onClick(DialogInterface dialog, int which)
            {
                dialog.dismiss();
            }
        }); 

        builder.create().show();
    } 

    /*
    // 拦截/屏蔽系统Home键
    public void onAttachedToWindow()
    {
        this.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD);
        super.onAttachedToWindow();
    }
    */