Dialog加载自定义布局的使用

private void setDialog() { 
        LayoutInflater inflater = LayoutInflater.from(MainActivity.this);  
        RelativeLayout layout = (RelativeLayout) inflater.inflate(R.layout.dialog_wuwangluo, null); 
        //新建对话框对象  
        Dialog mDialog= new AlertDialog.Builder(MainActivity.this).create(); 
        mDialog.setCancelable(true);  
        mDialog = mDialog.show();  
        //设置弹出框的宽高  
        mDialog.getWindow().setLayout(400, 300);  
        // 设置弹出框的透明度  
        WindowManager.LayoutParams lp = CartoonDialog.getWindow().getAttributes();  
        mDialog.getWindow().setAttributes(lp);  
        mDialog.getWindow().setContentView(layout);  
    }