介绍

A toast provides simple feedback about an operation in a small popup. It only fills the amount of

space required for the message and the current activity remains visible and interactive. For

example, navigating away from an email before you send it triggers a “Draft saved” toast to let

you know that you can continue editing later. Toasts automatically disappear after a timeout.

翻译：

Toast以一种小弹框的方式来给予用户反馈，它只需要消息可以显示出来的那小部分空间，同时Activity依

然可见可交互。例如，当你写邮件的时候退出，会触发“草稿已保存”的Toast来让你知道你以后可以继续

编辑这封邮件。Toast会在一段时间后自己消失。

类结构

Toast的成员

成员解释

实际使用

布局文件
activity_main.xml

<?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:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"android:paddingBottom="@dimen/activity_vertical_margin"android:paddingLeft="@dimen/activity_horizontal_margin"android:paddingRight="@dimen/activity_horizontal_margin"android:paddingTop="@dimen/activity_vertical_margin"tools:context="mraz.com.toastdemo.MainActivity"><Button
        android:id="@+id/bt_simple"android:layout_width="match_parent"android:layout_height="wrap_content"android:background="@color/colorAccent"android:text="Simple Toast" /><Button
        android:id="@+id/bt_custom"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_marginTop="30dp"android:background="@color/colorPrimary"android:text="Custom Toast" />
</LinearLayout>

自定义的Toast布局
custom_toast.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="match_parent"android:layout_height="40dp"android:background="@drawable/shape_bg"android:orientation="horizontal"><ImageView
        android:layout_width="40dp"android:layout_height="40dp"android:src="@drawable/ic_account_circle_black_24dp" /><TextView
        android:layout_width="wrap_content"android:layout_height="40dp"android:layout_marginLeft="10dp"android:layout_marginRight="10dp"android:gravity="center"android:text="This is a Custom Toast !"android:textStyle="italic" />
</LinearLayout>

代码内容

package mraz.com.toastdemo;import android.content.Context;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;public class MainActivity extends AppCompatActivity implements View.OnClickListener {Context mContext;Button btSimple, btCustom;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);mContext = this;btSimple = (Button) findViewById(R.id.bt_simple);btCustom = (Button) findViewById(R.id.bt_custom);btSimple.setOnClickListener(this);btCustom.setOnClickListener(this);}@Overridepublic void onClick(View view) {switch (view.getId()) {case R.id.bt_simple:Toast.makeText(mContext, " This is a simple toast", Toast.LENGTH_SHORT).show();break;case R.id.bt_custom:LayoutInflater layoutInflater = LayoutInflater.from(mContext);View custToast = layoutInflater.inflate(R.layout.custom_toast, null);Toast toast = new Toast(mContext);toast.setView(custToast);toast.setDuration(Toast.LENGTH_SHORT);toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);toast.show();break;}}
}

实际效果

备注

Toast的内容比较简单，但是开发过程中应该会经常用到，说不定偶尔还会碰到显示不出来的情况，不要忘记执行show()方法，当然，还有可能是其他的原因导致你的Toast无法显示~