volley 应用 GET POST请求 图片异步加载 – freexiaoyu – 博客园

<span style="color: #008080;">  1</span> <span style="color: #0000ff;">package</span><span style="color: #000000;"> com.example.volleydemo;</span>

2

3 import java.util.HashMap;

4 import java.util.Map;

5

6 import org.json.JSONObject;

7

8 import android.app.Activity;

9 import android.app.ProgressDialog;

10 import android.graphics.Bitmap;

11 import android.os.Bundle;

12 import android.support.v4.util.LruCache;

13 import android.util.Log;

14 import android.widget.ImageView;

15

16 import com.android.volley.Request;

17 import com.android.volley.RequestQueue;

18 import com.android.volley.Response;

19 import com.android.volley.VolleyError;

20 import com.android.volley.toolbox.ImageLoader;

21 import com.android.volley.toolbox.ImageLoader.ImageCache;

22 import com.android.volley.toolbox.ImageLoader.ImageListener;

23 import com.android.volley.toolbox.JsonObjectRequest;

24 import com.android.volley.toolbox.NetworkImageView;

25 import com.android.volley.toolbox.StringRequest;

26 import com.android.volley.toolbox.Volley;

27

28 /**

29 * Demo描述: 1 利用Volley获取JSON数据 2 利用Volley异步加载图片 1 利用NetworkImageView加载网路图片

30 *

31 */

32 public class MainActivity extends Activity {

33 private ImageView mImageView;

34 private NetworkImageView mNetworkImageView;

35

36 @Override

37 protected void onCreate(Bundle savedInstanceState) {

38 super.onCreate(savedInstanceState);

39 setContentView(R.layout.activity_main);

40 init();

41 }

42

43 private void init() {

44 mImageView = (ImageView) findViewById(R.id.imageView);

45 mNetworkImageView = (NetworkImageView) findViewById(R.id.networkImageView);

46 getJSONByVolley();

47 getJsonPost();

48 loadImageByVolley();

49 showImageByNetworkImageView();

50 }

51

52 /**

53 * 利用Volley获取JSON数据

54 */

55 private void getJSONByVolley() {

56 RequestQueue requestQueue = Volley.newRequestQueue(this);

57 String JSONDataUrl = “http://127.0.0.1:8099/api/api.ashx?action=product_list&ver=1&pageindex=1&pageCount=5”;

58 final ProgressDialog progressDialog = ProgressDialog.show(this,

59 “请稍后…”, “正在加载…”);

60

61 JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(

62 Request.Method.GET, JSONDataUrl, null,

63 new Response.Listener<JSONObject>() {

64 @Override

65 public void onResponse(JSONObject response) {

66 //处理返回的JSON数据

67 Log.e(“bbb”, response.toString());

68 if(progressDialog.isShowing() && progressDialog!=null){

69 progressDialog.dismiss(); }

70 }

71 }, new Response.ErrorListener() {

72 @Override

73 public void onErrorResponse(VolleyError arg0) {

74 // System.out.println(“sorry,Error”);

75 Log.e(“aaa”, arg0.toString());

76 }

77 });

78 requestQueue.add(jsonObjectRequest);

79 }

80

81 /***

82 * 以POST形式加载数据

83 */

84 private void getJsonPost() {

85 RequestQueue requestQueue = Volley.newRequestQueue(this);

86 String url = “http://127.0.0.1:8099/api/api.ashx”;

87 StringRequest postRequest = new StringRequest(Request.Method.POST, url,

88 new Response.Listener<String>() {

89 @Override

90 public void onResponse(String response) {

91 //处理返回的JSON数据

92 Log.d(“Response”, response);

93 }

94 }, new Response.ErrorListener() {

95 @Override

96 public void onErrorResponse(VolleyError error) {

97 // error

98 }

99 }) {

100 @Override

101 protected Map<String, String> getParams() {

102 //POST 参数

103 Map<String, String> params = new HashMap<String, String>();

104 params.put(“action”, “product_list”);

105 params.put(“ver”, “1”);

106 params.put(“pageindex”, “1”);

107 params.put(“pageCount”, “5”);

108 return params;

109 }

110 };

111 requestQueue.add(postRequest);

112 }

113

114 /**

115 * 利用Volley异步加载图片

116 *

117 * 注意方法参数: getImageListener(ImageView view, int defaultImageResId, int

118 * errorImageResId) 第一个参数:显示图片的ImageView 第二个参数:默认显示的图片资源 第三个参数:加载错误时显示的图片资源

119 */

120 private void loadImageByVolley() {

121 String imageUrl = “http://d.hiphotos.baidu.com/pic/w%3D310/sign=a00aca825aafa40f3cc6c8dc9b65038c/060828381f30e9246b63e1814c086e061c95f7bf.jpg”;

122 RequestQueue requestQueue = Volley.newRequestQueue(this);

123 final LruCache<String, Bitmap> lruCache = new LruCache<String, Bitmap>(

124 20);

125 ImageCache imageCache = new ImageCache() {

126 @Override

127 public void putBitmap(String key, Bitmap value) {

128 lruCache.put(key, value);

129 }

130

131 @Override

132 public Bitmap getBitmap(String key) {

133 return lruCache.get(key);

134 }

135 };

136 ImageLoader imageLoader = new ImageLoader(requestQueue, imageCache);

137 ImageListener listener = ImageLoader.getImageListener(mImageView,

138 R.drawable.ic_launcher, R.drawable.ic_launcher);

139 imageLoader.get(imageUrl, listener);

140 }

141

142 /**

143 * 利用NetworkImageView显示网络图片

144 */

145 private void showImageByNetworkImageView() {

146 String imageUrl = “http://d.hiphotos.baidu.com/pic/w%3D310/sign=a00aca825aafa40f3cc6c8dc9b65038c/060828381f30e9246b63e1814c086e061c95f7bf.jpg”;

147 RequestQueue requestQueue = Volley.newRequestQueue(this);

148 final LruCache<String, Bitmap> lruCache = new LruCache<String, Bitmap>(

149 20);

150 ImageCache imageCache = new ImageCache() {

151 @Override

152 public void putBitmap(String key, Bitmap value) {

153 lruCache.put(key, value);

154 }

155

156 @Override

157 public Bitmap getBitmap(String key) {

158 return lruCache.get(key);

159 }

160 };

161 ImageLoader imageLoader = new ImageLoader(requestQueue, imageCache);

162 mNetworkImageView.setTag(“url”);

163 mNetworkImageView.setImageUrl(imageUrl, imageLoader);

164 }

165

166 }

<span style="color: #008080;"> 1</span> <span style="color: #0000ff;">&lt;</span><span style="color: #800000;">RelativeLayout </span><span style="color: #ff0000;">xmlns:android</span><span style="color: #0000ff;">="http://schemas.android.com/apk/res/android"</span>

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