Handler

Handler的使用

常用方法

post(Runnable runnable)　　启动线程

removeCallbacks(Runnable runnable)　　取消线程

postDelayed(Runnable runnable,int time)　　延时启动线程

 

例、应用启动的欢迎界面

XML

首先是welcome.xml

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

 2 <RelativeLayout

 3     android:layout_width="fill_parent"

 4     android:layout_height="fill_parent"

 5     xmlns:android="http://schemas.android.com/apk/res/android">

 6 

 7     <ImageView

 8         android:layout_width="wrap_content"

 9         android:layout_height="wrap_content"

10         android:id="@+id/imageView"

11         android:layout_alignParentLeft="true"

12         android:layout_alignParentStart="true"

13         android:layout_alignParentTop="true"

14         android:layout_alignParentBottom="true"

15         android:src="@drawable/music"

16         android:layout_alignParentRight="true"

17         android:layout_alignParentEnd="true" />

18 

19 </RelativeLayout>

然后是main.xml

 1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

 2     xmlns:tools="http://schemas.android.com/tools"

 3     android:layout_width="match_parent"

 4     android:layout_height="match_parent"

 5     android:paddingLeft="@dimen/activity_horizontal_margin"

 6     android:paddingRight="@dimen/activity_horizontal_margin"

 7     android:paddingTop="@dimen/activity_vertical_margin"

 8     android:paddingBottom="@dimen/activity_vertical_margin"

 9     tools:context=".MyActivity">

10 

11     <TextView

12         android:text="@string/hello_world"

13         android:layout_width="wrap_content"

14         android:layout_height="wrap_content" />

15 

16 </RelativeLayout>

JAVA

welcome.java

import android.app.Activity;

import android.content.Intent;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.os.Bundle;

import android.os.Handler;

import android.view.Window;

import android.widget.ImageView;



public class welcome extends Activity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        requestWindowFeature(Window.FEATURE_NO_TITLE);

        setContentView(R.layout.welcome);

        new  Handler().postDelayed(new Runnable() {

            @Override

            public void run() {

                Intent mainIntent = new Intent(welcome.this,MyActivity.class);

                welcome.this.startActivity(mainIntent);

                welcome.this.finish();

            }

        },3000);

    }

}

　　这里使用requestWindowFeature(Window.FEATURE_NO_TITLE)将标题栏隐藏。创建一个子线程，延时3秒跳转的下一个Activity。

 

MyActivity.java

import android.app.Activity;

import android.os.Bundle;

import android.view.Menu;

import android.view.MenuItem;





public class MyActivity extends Activity {



    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_my);

    }





    @Override

    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.

        getMenuInflater().inflate(R.menu.my, menu);

        return true;

    }



    @Override

    public boolean onOptionsItemSelected(MenuItem item) {

        // Handle action bar item clicks here. The action bar will

        // automatically handle clicks on the Home/Up button, so long

        // as you specify a parent activity in AndroidManifest.xml.

        int id = item.getItemId();

        if (id == R.id.action_settings) {

            return true;

        }

        return super.onOptionsItemSelected(item);

    }

}