在 Android 中 Toast 是一个弹出的信息通知(如短信发送成功的提示,如记事本的“你刚才的内容已经保存”),功能 display a certain amount of time, and automtaically fades in and out,
most people just use it for debugging purpose.画外音:绝大多数人是如何用 Toast 来 debugging 的呢???
创建 Toast 信息的核心代码片段:
//短时间内“稍纵即逝”
Toast.makeText(getApplicationContext(), "your msg", Toast.LENGTH_SHORT).show();
//长时间内“稍纵即逝”
Toast.makeText(getApplicationContext(), "your msg", Toast.LENGTH_LONG).show();
本教程将展现,两个 Toast 例子:
1、普通的(Normal Toast view.)
2、自定义的(Custom Toast view.)
1. 普通的(Normal Toast View)
File : res/layout/activity_main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
tools:context=".MainActivity" >
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="show Toast" />
</LinearLayout>
File: MainActivity.java
package com.jiangge.toastdemo;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity {
private Button button;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) super.findViewById(R.id.button);
button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Context context = getApplicationContext();
CharSequence text = "Button is clicked, toast coming!";
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, text, duration);
toast.show();
}
});
}
}
运行结果:
2 TODO 自定义
===================================
看下官网文档:
Context context = getApplicationContext();
CharSequence text = "Hello toast!";
int duration = Toast.LENGTH_SHORT;
Toast toast = Toast.makeText(context, text, duration);
toast.show();
也可以使用方法串的形式:
Toast.makeText(context, text, duration).show();
Note:其实省去中间变量,代码可以简化很多:
package com.jiangge.toastdemo;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity {
private Button button;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) super.findViewById(R.id.button);
button.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// Context context = getApplicationContext();
// CharSequence text = "Button is clicked, toast coming!";
// int duration = Toast.LENGTH_SHORT;
Toast.makeText(getApplicationContext(), "Button is clicked, toast coming!", Toast.LENGTH_SHORT).show();
}
});
}
}