MainActivity:

package com.ruru.dialogfragment;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity implements View.OnClickListener, LoginDialogFragment.LoginInputListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        findViewById(R.id.btn_01).setOnClickListener(this);
        findViewById(R.id.btn_02).setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.btn_01:
                showDialog();
                break;
            case R.id.btn_02:
                showLoginDialog();
                break;
            default:
                break;
        }
    }

    /**
     * 顯示對話方塊---onCreateDialog---LoginDialogFragment
     */
    private void showLoginDialog() {
        LoginDialogFragment loginDialogFragment = new LoginDialogFragment();
        loginDialogFragment.show(getSupportFragmentManager(), "loginDialog");
    }

    /**
     * 顯示對話方塊---onCreateView---MyDialogFragment
     * remember:DialogFragment匯入的包是v4包，不是app下的，否則show()方法會報錯
     */
    private void showDialog() {
        MyDialogFragment myDialogFragment = new MyDialogFragment();
        myDialogFragment.show(getSupportFragmentManager(), "DialogFragment");
    }

    /**
     * MainActivity實現LoginInputListener介面
     */
    @Override
    public void onLoginInputComplete(String username, String password) {
        Toast.makeText(this, "使用者名稱===" + username + " 密碼===" + password, Toast.LENGTH_SHORT).show();
    }
}
 

MyDialogFragment:

package com.ruru.dialogfragment;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.DialogFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;

/**
 * Created by 27c1 on 2017/1/7.
 */
public class MyDialogFragment extends DialogFragment {

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        //去掉預設dialog的標題
        getDialog().requestWindowFeature(Window.FEATURE_NO_TITLE);
        View dialogView = inflater.inflate(R.layout.layout_dialog, null);
        return dialogView;
    }
}
 

package com.ruru.dialogfragment;

import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v4.app.DialogFragment;
import android.support.v7.app.AlertDialog;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.EditText;

/**
 * Created by 27c1 on 2017/1/7.
 */
public class LoginDialogFragment extends DialogFragment {

    private EditText et_username;
    private EditText et_password;

    /**
     * 介面
     */
    public interface LoginInputListener {
        void onLoginInputComplete(String username, String password);
    }

    @NonNull
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        View loginView = LayoutInflater.from(getActivity()).inflate(R.layout.layout_login, null);
        et_username = (EditText) loginView.findViewById(R.id.et_username);
        et_password = (EditText) loginView.findViewById(R.id.et_password);
        builder.setView(loginView);
        builder.setPositiveButton("signin", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
                //建立介面類並呼叫介面方法
                LoginInputListener listener = (LoginInputListener) getActivity();
                listener.onLoginInputComplete(et_username.getText().toString(), et_password.getText().toString());
            }
        });
        AlertDialog loginDialog = builder.create();
//        builder.show();---不能寫  會報錯
        return loginDialog;
    }
}
 

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

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:gravity="center">

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:src="@mipmap/ic_launcher" />

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="大家好"
            android:gravity="center"/>
    </LinearLayout>
</LinearLayout>

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

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <EditText
            android:id="@+id/et_username"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="請輸入使用者名稱" />

        <EditText
            android:id="@+id/et_password"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="請輸入密碼" />

        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="登入" />
    </LinearLayout>

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.ruru.dialogfragment.MainActivity">

    <Button
        android:id="@+id/btn_01"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="showDialog" />

    <Button
        android:id="@+id/btn_02"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="showLoginDialog" />
</LinearLayout>

友情連結：