知识点：
Toast消息机制LayoutInflater 、inflate（）动态加载布局文件开发规范MainActivity.java代码片.
package com.android.geoquiz; import androidx.appcompat.app.AppCompatActivity; import android.os.Bundle; import android.view.Gravity; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.Button; import android.widget.TextView; import android.widget.Toast; public class MainActivity extends AppCompatActivity { private Button mTrueButton; private Button mFalseButton; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mTrueButton =(Button) findViewById(R.id.true_button); mFalseButton = (Button) findViewById(R.id.false_button); mTrueButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Toast mToast = Toast.makeText(MainActivity.this, R.string.right_toast, Toast.LENGTH_SHORT); mToast.setGravity(Gravity.CENTER|Gravity.LEFT,0,0); mToast.show(); } }); mFalseButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { LayoutInflater mInFlater =getLayoutInflater(); ///调用Activity的getLayoutInflater() //inflate()动态载入一个res目录下的xml界面;find.View.By.Id()加载xml文件下的widget控件 View mLayout = mInFlater.inflate(R.layout.activity_toast,(ViewGroup)findViewById(R.id.custom_toast_container)); //找到指定位置(即mLayout)的text文本框，并修改其中的content TextView mText =(TextView) mLayout.findViewById(R.id.text); mText.setText("This is custom toast"); //Toast消息框机制 Toast toast = new Toast(getApplicationContext()); toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0); toast.setDuration(Toast.LENGTH_LONG); toast.setView(mLayout); toast.show(); } }); } }activity_main.xml代码片.
<?xml version="1.0" encoding="utf-8"?> <LinearLayout 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" android:gravity="center" android:orientation="vertical" tools:context=".MainActivity"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/question_content" android:padding="20dp"/> <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:orientation="horizontal" > <Button android:id="@+id/true_button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/true_button" /> <Button android:id="@+id/false_button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/false_button" /> </LinearLayout> </LinearLayout>activity_toast.xml代码片.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/custom_toast_container" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="fill_parent" android:padding="8dp" android:background="#DAAA" > <ImageView android:src="@drawable/ic_launcher_foreground" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginRight="8dp" /> <TextView android:id="@+id/text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textColor="#FFF" /> </LinearLayout>修改strings.xml 代码片.
<resources> <string name="app_name">GeoQuiz</string> <string name="question_content">canberra is the captital od Australia</string> <string name="true_button">TRUE</string> <string name="false_button">FALSE</string> <string name="right_toast">correct</string> <string name="wrong_toast">incorrect</string> </resources>谷歌官方文档： [1]: https://developer.android.google.cn/guide/topics/ui/notifiers/toasts
