自定义Dialog设置setCancelable(false)不起作用，按返回键还是会关闭Dialog！

解决方案，设置 Dialog 的返回键监听，不关闭Dialog

/**
     * 检测是否拥有写入系统权限的权限
     */
    private void showDialog(){
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { //版本在23及以上
            if (!Settings.System.canWrite(this)) {
                final CommonDialog deleteDialog = new CommonDialog(mContext);
                deleteDialog.setTitle("应用需要您授权\n\"修改系统设置\"的权限");
                deleteDialog.setPositiveButton(R.string.confirm,
                        new android.content.DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int which) {
                                deleteDialog.cancel();
                                Intent intent = new Intent(Settings.ACTION_MANAGE_WRITE_SETTINGS,
                                        Uri.parse("package:" + getPackageName()));
                                startActivity(intent);
                            }
                        });
                deleteDialog.setNegativeButton(R.string.cancel,
                        new android.content.DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int which) {
                                deleteDialog.cancel();
                                finish();
                            }
                        });
                deleteDialog.setCancelable(false);  //返回键还是会关闭Dialog
                deleteDialog.setOnKeyListener(new DialogInterface.OnKeyListener() {
                    @Override
                    public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
                        if (keyCode==KeyEvent.KEYCODE_BACK && event.getRepeatCount()==0) {
                            return true;    //返回true会截断返回键的点击事件，不做其他处理
                        } else {
                            return false;
                        }
                    }
                });
                deleteDialog.show();
            }
        }
    }