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