android - 如何使用 JSON 从 url 将图像和文本显示到 viewpager

Question

谁能给出一个正确的例子，说明如何将 URL 中的图像和文本显示到 viewPager 中。我找不到任何可以从中得到想法的完整示例。我是 android 的新手，我们将不胜感激。

Answer 1

我们可以把它分成几部分

<强>1。从url中获取Json数据

you can use volley plugin to get json data from url, for adding plugin to android studio do the following

在 android studio 中，打开 Gradle Scripts 下的 build.gradle(Module:app) 文件，在 dependencies 中添加以下行并同步 Gradle

compile 'com.android.volley:volley:1.0.0'

<强>2。将响应值设置为 View (即图像 url 到 imageview，文本值到 edittext/textview 等)

you can use Picasso plugin to set an image to Imageview from url. you need to add the following line in build.gradle (Module:app) file .it is same as the procedures we done to add volley plugin. and sync the gradle

 compile 'com.squareup.picasso:picasso:2.5.2'

让我们假设您的 Json Data In url 如下所示

{
    "image_url": "https://www.gstatic.com/webp/gallery/4.sm.jpg",
    "text_value": "some text"
}

在您的 java 页面中执行此操作:-

String url = "your_url_to_the_json_data";


// Request a string response, 
// you will get response from url as string


           StringRequest stringRequest = new StringRequest(Request.Method.POST, url,
                   new Response.Listener<String>() {
                       @Override
                       public void onResponse(String response) {


                           // you will get the response as string here
                           //String response holds the response from url

                          Log.d("response from url",response);
                         try
                         {

                          //converting string response to json object
                          JSONObject jsonObject = new JSONObject(response);


                          String my_text_value=jsonObject.getString("text_value");

                          String my_image_url=jsonObject.getString("image_url");

                          // now you got your text and image urls in the above strings


                          //now set it your imageview and edittext

                          my_edittext.setText(my_text_value);

                          //An external plugin named picasso is used to set image to an imageview from pic url

                          Picasso.with(this).load(my_image_url).into(my_imageview);


                          }

                          catch (JSONException e) {
                            Toast.makeText(getActivity(), "json exception",Toast.LENGTH_LONG).show();
                            e.printStackTrace();

                        }



                       }
                   }, new Response.ErrorListener() {
               @Override
               public void onErrorResponse(VolleyError error) {

                   //this part will work if there is any error

                   System.out.println("Something went wrong!");
                   error.printStackTrace();

               }

           })
           {
               @Override
               protected Map<String, String> getParams()
               {
                   Map<String, String> params = new HashMap<String, String>();


                   //you can pass parameters ,if you want to

                   //in this case its not needed


                   //params.put("parameter1", value1);
                  // params.put("parameter2",value2);



                   return params;
               }
           };


           // Add the request to the queue

           Volley.newRequestQueue(this).add(stringRequest); 

不要忘记用您的值更改以下值

* `String url = "your_url_to_the_json_data";`

   change `"your_url_to_the_json_data"` with your url

* `my_edittext.setText(my_text_value);`

    change `my_edittext` to your edittext or textView object

* `Picasso.with(this).load(my_image_url).into(my_imageview);`

  change `my_imageview` to your imageview object