今天来实现一下android下的一款简单的网络图片查看器
界面如下:
images/loading.gif' data-original="http://images2015.cnblogs.com/blog/617081/201606/617081-20160627154356140-509652093.jpg" />
代码如下:
<LinearLayout ="http://schemas.android.com/apk/res/android" ="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context=".MainActivity" > <ImageView android:id="@+id/iv" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_weight="1000" /> <EditText android:singleLine="true" android:text="http://img01.sogoucdn.com/app/a/100540002/1047586.jpg" android:id="@+id/et_path" android:layout_width="fill_parent" android:layout_height="wrap_content" android:hint="请输入图片路径" /> <Button android:layout_width="fill_parent" android:layout_height="wrap_content" android:onClick="click" android:text="浏览" /></LinearLayout>
代码如下:
package com.wuyudong.imagesviewer;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import org.apache.http.HttpConnection;import android.os.Bundle;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.text.TextUtils;import android.view.Menu;import android.view.View;import android.widget.EditText;import android.widget.ImageView;import android.widget.Toast;public class MainActivity extends Activity { private EditText et_path; private ImageView iv; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); et_path = (EditText) findViewById(R.id.et_path); iv = (ImageView) findViewById(R.id.iv); } public void click(View view) { String path = et_path.getText().toString().trim(); if (TextUtils.isEmpty(path)) { Toast.makeText(this, "图片路径不能为空", 0).show(); } else { // 连接服务器get请求获取图片 try { URL url = new URL(path); // 根据url发送http的请求 HttpURLConnection conn = (HttpURLConnection) url .openConnection(); // 设置请求的方式 conn.setRequestMethod("GET"); conn.setConnectTimeout(5000); conn.setReadTimeout(5000); conn.setRequestProperty( "User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.101 Safari/537.36"); int code = conn.getResponseCode(); if (code == 200) { InputStream is = conn.getInputStream(); Bitmap bitmap = BitmapFactory.decodeStream(is); iv.setImageBitmap(bitmap); } else { Toast.makeText(this, "显示图片失败", 0).show(); } } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); Toast.makeText(this, "访问获取图片失败", 0).show(); } } }}
添加权限:android.permission.INTE.NET
运行后报错:android.os.NetworkOnMainThreadException
解释一下,从Honeycomb SDK(3.0)开始,google不再允许网络请求(HTTP、Socket)等相关操作直接在Main Thread类中,其实本来就不应该这样做,直接在UI线程进行网络操作,会阻塞UI、用户体验相当差!
所以,在Honeycomb SDK(3.0)以下的版本,你还可以继续在Main Thread里这样做,在3.0以上,就不行了
具体解决办法见后文
原标题:Android 网络图片查看器
关键词:Android