标签:volley lrucache jsonobjectrequest stringrequest imageloader
activity_main.xml 里面什么也没有
AndroidManifest.xml(重点是android:name="com.example.volley.MyApplication")
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.volley" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="18" android:targetSdkVersion="18" /> <application android:name="com.example.volley.MyApplication" android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" 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> <uses-permission android:name="android.permission.INTERNET" /> </manifest>
MyApplication
package com.example.volley; import com.android.volley.RequestQueue; import com.android.volley.toolbox.Volley; import android.app.Application; public class MyApplication extends Application { public static RequestQueue queue; /** 一旦创建就创建RequestQueue请求队列 */ @Override public void onCreate() { super.onCreate(); queue = Volley.newRequestQueue(getApplicationContext()); } /** 对外提供静态的方法 */ public static RequestQueue getHttpRequestQueue() { return queue; } }
package com.example.volley; import java.io.File; import java.io.FileInputStream; import java.io.InputStream; import java.util.HashMap; import java.util.Map; import org.json.JSONObject; import com.android.volley.Request.Method; import com.android.volley.AuthFailureError; import com.android.volley.Response; import com.android.volley.Response.Listener; import com.android.volley.VolleyError; import com.android.volley.toolbox.JsonObjectRequest; import com.android.volley.toolbox.StringRequest; import android.app.Activity; import android.os.Bundle; import android.util.Log; import android.widget.Toast; public class MainActivity extends Activity { /** * 关联activity,退出之后取消所有的网络请求,释放资源 */ @Override protected void onStop() { super.onStop(); MyApplication.getHttpRequestQueue().cancelAll("abcGet"); } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // volley_get(); volley_post(); } /** * get请求方式 */ private void volley_get() { /** * String类型 */ String url = "http://www.imooc.com/api/teacher?type=4&num=30"; StringRequest request = new StringRequest(Method.GET, url, new Listener<String>() { @Override public void onResponse(String arg0) { //返回正确后的操作 Log.e("TAG", ""+arg0); } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError arg0) { } }); // 设置标签 request.setTag("abcGet"); MyApplication.getHttpRequestQueue().add(request); MyApplication.getHttpRequestQueue().start(); /** * JsonObjectRequest类型 因为get参数已经在url写好了,所以传空即可 */ JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Method.GET, url, null, new Listener<JSONObject>() { @Override public void onResponse(JSONObject arg0) { Toast.makeText(MainActivity.this, arg0.toString(), 0) .show(); } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError arg0) { } }); // 设置标签 jsonObjectRequest.setTag("bcdGet"); MyApplication.getHttpRequestQueue().add(jsonObjectRequest); MyApplication.getHttpRequestQueue().start(); /** * 还有jsonArray方式,这里省略了。。。 */ } /** * post请求方式 */ private void volley_post() { /** * StringRequest---post方式 */ String url = "http://www.imooc.com/api/teacher?"; StringRequest request = new StringRequest(Method.POST, url, new Listener<String>() { @Override public void onResponse(String arg0) { Log.e("TAG", ""+arg0); } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError arg0) { } }) { @Override protected Map<String, String> getParams() throws AuthFailureError { //传递参数 Map<String, String> map = new HashMap<String, String>(); map.put("type", "4"); map.put("num", "30"); return map; } }; // 设置标签 request.setTag("abcPost"); MyApplication.getHttpRequestQueue().add(request); MyApplication.getHttpRequestQueue().start(); /** * jsonObject--post方式 */ HashMap<String, String> map = new HashMap<String, String>(); map.put("type", "4"); map.put("num", "30"); // 将map转为jsonObject对象 JSONObject object = new JSONObject(map); JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Method.POST, url, object, new Listener<JSONObject>() { @Override public void onResponse(JSONObject arg0) { Log.e("TAG", arg0.toString()); } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError arg0) { } }); // 设置标签 jsonObjectRequest.setTag("bcdPost"); MyApplication.getHttpRequestQueue().add(jsonObjectRequest); MyApplication.getHttpRequestQueue().start(); } }
AndroidManifest.xml(重点是 android:name="com.example.volleyimagedemo.MyApplication")
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.volleyimagedemo" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="18" android:targetSdkVersion="18" /> <application android:name="com.example.volleyimagedemo.MyApplication" android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" 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> <uses-permission android:name="android.permission.INTERNET"/> </manifest>activity_main.xml
<LinearLayout 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:orientation="vertical" tools:context="com.example.volleyimagedemo.MainActivity" > <!-- 方式一 --> <ImageView android:id="@+id/imageview1" android:layout_width="fill_parent" android:layout_height="wrap_content" /> <!-- 方式二 --> <ImageView android:id="@+id/imageview2" android:layout_width="fill_parent" android:layout_height="wrap_content" /> <!-- 方式三 --> <com.android.volley.toolbox.NetworkImageView android:id="@+id/networkImageview" android:layout_width="fill_parent" android:layout_height="wrap_content" > </com.android.volley.toolbox.NetworkImageView> </LinearLayout>
package com.example.volleyimagedemo; import com.android.volley.RequestQueue; import com.android.volley.toolbox.Volley; import android.app.Application; public class MyApplication extends Application { public static RequestQueue queue; @Override public void onCreate() { super.onCreate(); queue = Volley.newRequestQueue(getApplicationContext()); } public static RequestQueue getHttpRequestQueue() { return queue; } }
package com.example.volleyimagedemo; import android.graphics.Bitmap; import android.util.LruCache; import com.android.volley.toolbox.ImageLoader.ImageCache; public class BitMapCache implements ImageCache{ public LruCache<String, Bitmap> cache; //超过10兆,自动回收 public int max = 10*1024*1024; public BitMapCache(){ cache = new LruCache<String, Bitmap>(max){ @Override protected int sizeOf(String key, Bitmap value) { return value.getRowBytes()*value.getHeight(); } }; } @Override public Bitmap getBitmap(String arg0) { return cache.get(arg0); } @Override public void putBitmap(String arg0, Bitmap arg1) { cache.put(arg0, arg1); } }
package com.example.volleyimagedemo; import android.app.Activity; import android.graphics.Bitmap; import android.graphics.Bitmap.Config; import android.os.Bundle; import android.widget.ImageView; import com.android.volley.Response; import com.android.volley.Response.Listener; import com.android.volley.VolleyError; import com.android.volley.toolbox.ImageLoader; import com.android.volley.toolbox.ImageLoader.ImageListener; import com.android.volley.toolbox.ImageRequest; import com.android.volley.toolbox.NetworkImageView; public class MainActivity extends Activity { private ImageView imageview1; private ImageView imageview2; private NetworkImageView networkImageView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); /** 获取控件、图片url地址 */ imageview1 = (ImageView) findViewById(R.id.imageview1); imageview2 = (ImageView) findViewById(R.id.imageview2); networkImageView = (NetworkImageView) findViewById(R.id.networkImageview); String url = "http://img.mukewang.com/55237dcc0001128c06000338-300-170.jpg"; /** * 下载图片的第二种方式ImageLoader+BitMapCache */ // imageCache单肚使用是不到缓存效果,需要结合lruCache ImageLoader imageLoader1 = new ImageLoader( MyApplication.getHttpRequestQueue(), new BitMapCache()); networkImageView.setDefaultImageResId(R.drawable.ic_launcher); networkImageView.setErrorImageResId(R.drawable.ic_launcher); networkImageView.setImageUrl(url, imageLoader1); /** * 下载图片的第三种种方式 */ ImageLoader imageLoader2 = new ImageLoader( MyApplication.getHttpRequestQueue(), new BitMapCache()); // view视图,默认的图片,错误的图片 ImageListener listener = imageLoader1.getImageListener(imageview2, R.drawable.ic_launcher, R.drawable.ic_launcher); imageLoader2.get(url, listener); /** * 下载网络图片的第一种方式ImageRequest */ // // 0 是原图的方式加载--Config.RGB_565原图 ImageRequest imageRequest = new ImageRequest(url, new Listener<Bitmap>() { // @Override public void onResponse(Bitmap arg0) { imageview1.setImageBitmap(arg0); } }, 0, 0, Config.RGB_565, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError arg0) { imageview1 .setBackgroundResource(R.drawable.ic_launcher); } }); MyApplication.getHttpRequestQueue().add(imageRequest); MyApplication.getHttpRequestQueue().start(); } }
版权声明:本文为博主原创文章,未经博主允许不得转载。
Volley的Get、Post方式(JsonObjectRequest、StringRequest)以及Volley获取图片的3种方式
标签:volley lrucache jsonobjectrequest stringrequest imageloader
原文地址:http://blog.csdn.net/u013210620/article/details/47335671