取不到AlertDialog上的edittext的值

1首先使用的是new AlertDialog.Builder(this);对象而不是AlertDialog

2AlertDialog上的布局需要调用View.inflate(this, R.layout.name_pw, null);进行初始化

代码

 AlertDialog.Builder builder = new AlertDialog.Builder(this);
        View inflate = View.inflate(this, R.layout.name_pw, null);
        builder.setTitle("请输入用户名和密码")
               .setView(R.layout.name_pw)
               .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                        Log.e("wy", "onClick: "+this.toString()+ " 88: "+MainActivity.this.toString());
                        edtUser = (EditText) inflate.findViewById(R.id.edt_user);
                        edtPw = (EditText) inflate.findViewById(R.id.edt_pw);
                        Log.e("wy", "use: "+edtUser.getText().toString()+
                                " pw:"+edtPw.getText().toString() );

                    }
                })
                .setNegativeButton("取消", null);

        builder.show();

name_pw.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:orientation="vertical"
    android:layout_height="wrap_content" >

    <EditText
        android:id="@+id/edt_user"
        android:text="xiaoming"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
    <EditText
        android:id="@+id/edt_pw"
        android:text="123456"
        android:password="true"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>