Android应用开发 对话框创建

private void showDialog(String msg){
Builder builder =**new AlertDialog.Builder(HttpUtil.this);**
// AlertDialog.Builder builder =new Builder(HttpUtil.this);
builder.setMessage(msg)
.setCancelable(false)
.setPositiveButton("确定", new DialogInterface.OnClickListener(){
public void onClick (DialogInterface dialog,int id){

       }
   });
   AlertDialog alert =builder.create();
   alert.show();

}
加粗部分提示The constructor AlertDialog.Builder(HttpUtil) is undefined

new AlertDialog.Builder需要传递的参数是上下文，你的HttpUtil.this是什么？如果HttpUtil.this是Activity，那么改成new AlertDialog.Builder(((Activity)HttpUtil.this));或者 new AlertDialog.Builder(getActivity());

new AlertDialog.Builder(Context context) 不是需要HttpUtil.this

HttpUtil是什么类？AlertDialog.Builder需要上下文对象来构造，改为：new AlertDialog.Builder(getActivity());，或者传递Context对象

//1、得到对话框的构造器，用来构造对话框的模版      
    AlertDialog.Builder builder = new Builder(this);   
    //2、构造对话框的模版
    //设置标题
    builder.setTitle("提醒：");
    //设置提示信息
    builder.setMessage("若练此功，必先自宫！");
    //设置确定按钮
    builder.setPositiveButton("确定自宫", new OnClickListener() {     
        @Override
        public void onClick(DialogInterface dialog, int which) {
            Toast.makeText(MainActivity.this, "即使自宫，也未必成功", 0).show();
        }
    });
    //设置取消按钮
    builder.setNegativeButton("想想再说", new OnClickListener() {    
        @Override
        public void onClick(DialogInterface dialog, int which) {
            Toast.makeText(MainActivity.this, "若不自宫一定不会成功", 0).show();
        }
    });    
    //3、使用构造器创建一个对话框
    AlertDialog dialog = builder.create();     
    //4、显示对话框
    dialog.show();