diff --git a/.idea/vcs.xml b/.idea/vcs.xml
new file mode 100644
index 0000000..94a25f7
--- /dev/null
+++ b/.idea/vcs.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/app/build.gradle b/app/build.gradle
index 59b047e..3791034 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -19,10 +19,11 @@ android {
 }
 
 dependencies {
-    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    implementation fileTree(include: ['*.jar'], dir: 'libs')
     implementation 'com.android.support:appcompat-v7:28.0.0'
     implementation 'com.android.support.constraint:constraint-layout:1.1.3'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
+    implementation 'com.android.support:design:28.0.0'
 }
diff --git a/app/src/main/java/me/jj97181818/ch07_datetimepicker/MainActivity.java b/app/src/main/java/me/jj97181818/ch07_datetimepicker/MainActivity.java
index a3f1d2c..dec9c1f 100644
--- a/app/src/main/java/me/jj97181818/ch07_datetimepicker/MainActivity.java
+++ b/app/src/main/java/me/jj97181818/ch07_datetimepicker/MainActivity.java
@@ -2,6 +2,7 @@ package me.jj97181818.ch07_datetimepicker;
 
 import android.app.DatePickerDialog;
 import android.app.TimePickerDialog;
+import android.support.design.widget.Snackbar;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
 import android.view.View;
@@ -51,8 +52,10 @@ public class MainActivity extends AppCompatActivity implements View.OnClickListe
         else
             txDate.setText("日期：" + year + "/" + (month + 1) + "/" + dayOfMonth);
 
-        tos.setText("owo");
+        tos.setText("我是一片吐司～～～");
         tos.show();
+
+        Snackbar.make(findViewById(R.id.root), "日期：" + year + "/" + (month + 1) + "/" + dayOfMonth, Snackbar.LENGTH_SHORT).show();
     }
 
     @Override
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index c302185..c8d0cad 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -2,6 +2,7 @@
 <android.support.constraint.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:id="@+id/root"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     tools:context=".MainActivity">