Android Toast简介

　　Toast是Android中一种提供给用户简短信息的视图，该视图已浮于应用程序之上的形式呈现给用户。因为它并不获得焦点，即使用户正在输入什么也不会受到影响。它的目标是尽可能以不显眼的方式，使用户看到你提供的信息。显示的时间是有限制的，过一段时间后会自动消失，不过Toast本身可以控制显示时间的长短；

Toast的不同显示样式：

代码如下：

activity_main.xml

<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" >

    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/button1" />

    <Button
        android:id="@+id/button2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/button2" />

    <Button
        android:id="@+id/button3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/button3" />

    <Button
        android:id="@+id/button4"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/button4" />

    <Button
        android:id="@+id/button5"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/button5" />

    <Button
        android:id="@+id/button6"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/button6" />

</LinearLayout>

strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">Toast</string>
    <string name="hello_world">Hello world!</string>
    <string name="action_settings">Settings</string>
    <string name="button1">系统默认的Toast</string>
    <string name="button2">自定义位置的Toast</string>
    <string name="button3">只显示图片的Toast</string>
    <string name="button4">显示图片和文字的Toast</string>
    <string name="button5">自定义布局的Toast</string>
    <string name="button6">其他线程的Toast</string>
    <string name="text_view1">自定义布局的Toast</string>
    <string name="text_view2">自定义布局：</string>

</resources>

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="match_parent"
    android:background="#708090"
    android:orientation="vertical"
    android:padding="5dp" >

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/text_view2" />

    <ImageView
        android:id="@+id/img"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/text_view1" />

</LinearLayout>

MainActivity.java

package com.xiaozhang.wifi;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.Toast;

public class MainActivity extends Activity {

    private Toast toast = null;
    Handler handler = new Handler();

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

        findViewById(R.id.button1).setOnClickListener(new ButtonClick());
        findViewById(R.id.button2).setOnClickListener(new ButtonClick());
        findViewById(R.id.button3).setOnClickListener(new ButtonClick());
        findViewById(R.id.button4).setOnClickListener(new ButtonClick());
        findViewById(R.id.button5).setOnClickListener(new ButtonClick());
        findViewById(R.id.button6).setOnClickListener(new ButtonClick());

    }

    public void showToast() {
        handler.post(new Runnable() {
            @Override
            public void run() {
                Toast.makeText(getApplicationContext(), "其他线程的Toast",
                        Toast.LENGTH_SHORT).show();
            }
        });
    }

    class ButtonClick implements OnClickListener {

        @SuppressLint("InflateParams")
        @SuppressWarnings("static-access")
        @Override
        public void onClick(View v) {
            switch (v.getId()) {
            case R.id.button1:
                toast.makeText(MainActivity.this, "默认的Toast", Toast.LENGTH_LONG)
                        .show();
                break;
            case R.id.button2:
                // getApplicationContext()得到程序当前的默认Context
                toast = Toast.makeText(getApplicationContext(), "自定义位置的Toast",
                        Toast.LENGTH_LONG);
                // 设置Toast的位置
                toast.setGravity(Gravity.CENTER, toast.getXOffset() / 2,
                        toast.getYOffset() / 2);
                toast.show();
                break;
            case R.id.button3:
                toast = Toast.makeText(MainActivity.this, "只显示图片的Toast",
                        Toast.LENGTH_LONG);
                ImageView img = new ImageView(MainActivity.this);
                img.setImageResource(R.drawable.right);
                toast.setView(img);
                toast.show();
                break;
            case R.id.button4:
                toast = Toast.makeText(getApplicationContext(), "显示图片和文字的Toast",
                        Toast.LENGTH_LONG);
                LinearLayout layout = (LinearLayout) toast.getView();
                ImageView img1 = new ImageView(getApplicationContext());
                img1.setImageResource(R.drawable.right);
                layout.addView(img1, 0);
                toast.show();
                break;
            case R.id.button5:
                // LayoutInflater作用是将layout的xml布局文件实例化为View类对象
                LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                View view = inflater.inflate(R.layout.toast, null);

                Toast toast = new Toast(getApplicationContext());
                // 在view中查找ImageView控件
                ImageView image = (ImageView) view.findViewById(R.id.img);
                image.setImageResource(R.drawable.right);
                toast.setView(view);
                toast.show();
                break;
            case R.id.button6:
                new Thread(new Runnable() {
                    public void run() {
                        showToast();
                    }
                }).start();
                break;
            }
        }

    }
}

PS:记得添加图片：right.png

参考自：http://liangruijun.blog.51cto.com/3061169/638913