[App]Android Studio First App

准备着看Android Studio的体验如何。

通过Android Studio构建一个默认的项目，添加一些元素

<RelativeLayout

    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:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivityFragment">

    <TextClock

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:id="@+id/textClock"

        android:layout_marginStart="32dp"

        android:layout_toEndOf="@+id/img1" />

    <AnalogClock

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:id="@+id/analogClock"

        android:layout_alignParentEnd="true" />

    <EditText

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:inputType="textPassword"

        android:ems="10"

        android:id="@+id/editText"

        android:layout_alignTop="@+id/editText2"

        android:layout_alignStart="@+id/editText2"

        android:layout_marginTop="25dp"

        android:layout_marginRight="150dp" />

    <Button

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="LoadImage"

        android:id="@+id/btnOk"

        android:onClick="btnOnClick"

        android:layout_alignParentStart="true" />

    <TextView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="UserName"

        android:id="@+id/userName"

        android:layout_alignBaseline="@+id/editText2"

        android:layout_alignBottom="@+id/editText2"

        android:layout_alignParentStart="true" />

    <TextView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="PassWord"

        android:id="@+id/pwd"

        android:layout_below="@+id/editText2"

        android:layout_alignParentStart="true" />

    <ImageView

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:id="@+id/img1"

        android:layout_alignParentBottom="true"

        android:layout_alignEnd="@+id/editText"

        />

    <EditText

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:inputType="textPersonName"

        android:text="Name"

        android:ems="10"

        android:id="@+id/editText2"

        android:layout_below="@+id/btnOk"

        android:layout_toEndOf="@+id/pwd"

        android:layout_marginRight="150dp" />

</RelativeLayout>

修改AndroidManifest.xml，由于该Demo涉及到从网络下载图片，所以需要添加INTERNET的权限。并设置

android.intent.action.MAIN

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

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

    package="com.example.dawnwind.test2" >

<uses-permission android:name="android.permission.INTERNET" />

    <application

        android:allowBackup="true"

        android:icon="@mipmap/ic_launcher"

        android:label="Slark"

        android:theme="@style/AppTheme" >

        <activity

            android:name=".MainActivity"

            android:label="@string/app_name" >

            <intent-filter>

                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />

            </intent-filter>

        </activity>

    </application>

</manifest>

然后修改逻辑代码：

package com.example.dawnwind.test2;

import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.MalformedURLException;

import java.net.URL;

import android.os.AsyncTask;

import android.support.v4.app.Fragment;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.view.View;

import android.widget.Button;

import android.widget.ImageView;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

/**

 * A placeholder fragment containing a simple view.

 */

public class MainActivityFragment extends Fragment {

    private ImageView mImageView;

    private Button mBtnLoad;

    private int currentImg = 0;

    private String[] mimageList = new String[]{

       "http://www.bz55.com/uploads/allimg/150701/140-150F1141919-50.jpg",

       "http://b.img.wpxap.com/data/attachment/forum/201507/28/114816eq42vmkvkihsmt88.jpg",

       "http://ww3.sinaimg.cn/mw1024/5e9ffd77gw1euv1m3sbn4j211y0lcwla.jpg",

       "http://ww1.sinaimg.cn/mw1024/5e9ffd77jw1euqs0kiwkij20f00qo40w.jpg",

       "http://ww3.sinaimg.cn/mw1024/5e9ffd77jw1euh1p5we31j219c0pk479.jpg"

    };

    public MainActivityFragment() {

    }

    @Override

    public View onCreateView(LayoutInflater inflater, ViewGroup container,

                             Bundle savedInstanceState) {

        View viewItem = inflater.inflate(R.layout.fragment_main, container, false);

        mImageView = (ImageView)viewItem.findViewById(R.id.img1);

        mBtnLoad   = (Button)viewItem.findViewById(R.id.btnOk);

        // set onclick

        mBtnLoad.setOnClickListener(new View.OnClickListener()

        {

            @Override

            public void onClick(View v)

            {

                ++currentImg;

                if (currentImg >= mimageList.length)

                {

                    currentImg = 0;

                }

                //改变ImageView里显示的图片

                //mImageView.setImageResource(mimageList[currentImg]);

                // run asynctask

                new ImageLoaderTask().execute(mimageList[currentImg]);

                String s_info = "Load: " + String.valueOf(currentImg);

                mBtnLoad.setText(s_info);

            }

        });

        new ImageLoaderTask().execute(mimageList[0]);

        return viewItem;

    }

    // Not suggested to do network jobs in main thread, Thus create a child thread to do work

    class ImageLoaderTask extends AsyncTask<String, Void , Bitmap> {

        // Will run in sub-thread

        protected  Bitmap doInBackground(String... params) {

            return getHttpBitmap(params[0]);

        }

        // Will call in gui-thread

        protected void onPostExecute(Bitmap result) {

            mImageView.setImageBitmap(result);

        }

    }

    public static Bitmap getHttpBitmap(String url){

        URL myFileURL;

        Bitmap bitmap=null;

        try{

            myFileURL = new URL(url);

            //????

            HttpURLConnection conn=(HttpURLConnection)myFileURL.openConnection();

            //???????6000???conn.setConnectionTiem(0);????????

            conn.setConnectTimeout(6000);

            //?????????

            conn.setDoInput(true);

            //?????

            conn.setUseCaches(false);

            //???????????

            conn.connect();

            //?????

            InputStream is = conn.getInputStream();

            //??????

            bitmap = BitmapFactory.decodeStream(is);

            //?????

            is.close();

        }catch(Exception e){

            e.printStackTrace();

        }

        return bitmap;

    }

}

最终效果

巴特西

[App]Android Studio First App

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