弹出对话框

1.创建一个Builder

Builder builder =new Builder(Mainactivity.this);

2.设置标题

builder.setTitle("随便写");

3.设置内容

builder.setMessage("随便写");

4.设置按钮

builder.setPositiveButton("确定",new OnClickListener(){

@Override
public void onClick(DialogInterface dialog, int which) {
    //notify();

}});

builder.setNativeButton("取消",null);

5.展示对话框

builder.show();