DatePicker 使用 Material Design 不显示

Question

I am trying to create a button that when clicked opens a calendar using material design with android studio

but clicking it closes the app.

I implement the librery in the gradle

 implementation 'com.google.android.material:material:1.3.0-alpha01'

This my code Java

package com.niccode.myapplication;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;

import com.google.android.material.datepicker.MaterialDatePicker;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button mdatePicker = findViewById(R.id.button);
        MaterialDatePicker.Builder builder = MaterialDatePicker.Builder.datePicker();
        builder.setTitleText("Select");
        final MaterialDatePicker materialDatePicker = builder.build();

        mdatePicker.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                materialDatePicker.show(getSupportFragmentManager(), "DATE_PICKER");
            }
        });
    }
}

This is xml code

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/button"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

Answer 1

just change your appTheme to materialTheme in styles.xml:

<style name="AppTheme" parent="Theme.MaterialComponents.Light.NoActionBar">

Answer 2

Try below style

<style name="AppTheme" parent="Theme.MaterialComponents.Light.Bridge">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <!-- Add these -->
        <item name="materialCalendarStyle">@style/Widget.MaterialComponents.MaterialCalendar</item>
        <item name="materialCalendarFullscreenTheme">@style/ThemeOverlay.MaterialComponents.MaterialCalendar.Fullscreen</item>
        <item name="materialCalendarTheme">@style/ThemeOverlay.MaterialComponents.MaterialCalendar</item>
    </style>