Java 显示json到文本视图强制关闭
我想通过php显示mysql数据库中的产品详细信息，并在android textview中显示。场景如下：单击产品列表时。它将产品id传递给名为productdetail的新意图。该id将用于通过php获取mysql db中的详细产品。PHP文件已成功返回json格式的数据。但当我运行程序时，它会在打开productdetail时强制关闭。我在这个方法中发现的问题是new GetProductDetails（）.execute（）； 这是我的密码： getproductdetail.java 公共类ProductDetail扩展了活动{Java 显示json到文本视图强制关闭,java,php,android,json,Java,Php,Android,Json,我想通过php显示mysql数据库中的产品详细信息，并在android textview中显示。场景如下：单击产品列表时。它将产品id传递给名为productdetail的新意图。该id将用于通过php获取mysql db中的详细产品。PHP文件已成功返回json格式的数据。但当我运行程序时，它会在打开productdetail时强制关闭。我在这个方法中发现的问题是new GetProductDetails（）.execute（）； 这是我的密码： getproductdetail.java 公
TextView txtName;
TextView txtVersion;
TextView txtDesc;
String pid;
//progress dialog
private ProgressDialog pDialog;
//Creating JSON Parser object
JSONParser jsonParser = new JSONParser();
//url to get all products list
private static String url_product_details = "http://visioinformatika.com/demo/appswitcher/bin/get_product_details.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "products";
private static final String TAG_PID = "pid";
private static final String TAG_NAME = "product_name";
private static final String TAG_VERSION = "app_version";
private static final String TAG_PDETAIL = "product_detail";
// products JSONArray
JSONArray products = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_product_detail);
// getting product details from intent
Intent i = getIntent();
// getting product id (pid) from intent
pid = i.getStringExtra(TAG_PID);
//txtName = (TextView) findViewById(R.id.app_name);
//txtName.setText(pid);
// Getting complete product details in background thread
new GetProductDetails().execute();
}
/**
* Background Async Task to Get complete product details
* */
class GetProductDetails extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(ProductDetail.this);
pDialog.setMessage("Loading product details. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
/**
* Getting product details in background thread
* */
protected String doInBackground(String... params) {
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
// Check for success tag
int success;
try {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("pid", pid));
// getting product details by making HTTP request
// Note that product details url will use GET request
JSONObject json = jsonParser.makeHttpRequest(
url_product_details, "GET", params);
// check your log for json response
Log.d("Single Product Details", json.toString());
// json success tag
success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// successfully received product details
JSONArray productObj = json
.getJSONArray(TAG_PRODUCTS); // JSON Array
// get first product object from JSON Array
JSONObject product = productObj.getJSONObject(0);
// product with this pid found
// Edit Text
txtName = (TextView) findViewById(R.id.app_name);
txtVersion = (TextView) findViewById(R.id.app_version);
txtDesc = (TextView) findViewById(R.id.desc_app);
// display product data in TextView
txtName.setText(product.getString(TAG_NAME));
txtVersion.setText(product.getString(TAG_VERSION));
txtDesc.setText(product.getString(TAG_PDETAIL));
}else{
// product with pid not found
}
} catch (JSONException e) {
e.printStackTrace();
}
}
});
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog once got all details
pDialog.dismiss();
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.product_detail, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
对不起，我英语不好。我是android新手：）请将此代码放入postexecute方法。UI无法填充主线程
// display product data in TextView
txtName.setText(product.getString(TAG_NAME));
txtVersion.setText(product.getString(TAG_VERSION));
txtDesc.setText(product.getString(TAG_PDETAIL));
txtName = (TextView) findViewById(R.id.app_name);
txtVersion = (TextView) findViewById(R.id.app_version);
txtDesc = (TextView) findViewById(R.id.desc_app);
您必须改进您的编码风格，在onCreate中初始化视图 如果 您希望在后台更新UI，然后继续 否则
在doInBackground中进行后台处理，最后更新asynTask的onPostExecute中的视图。将此代码放入onPreExecute（）中，如下所示
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
// product with this pid found
// Edit Text
txtName = (TextView) findViewById(R.id.app_name);
txtVersion = (TextView) findViewById(R.id.app_version);
txtDesc = (TextView) findViewById(R.id.desc_app);
pDialog.show();
}
我已经把代码放在我的post execute中了。但是仍然得到错误警告。对不起，…我是android新手，对java编程知之甚少。我已经把代码放在我的post execute方法中了。但是这是显示错误“产品无法解决”，谢谢你的建议robbin:），我已经初始化了textView。但是我不明白如何在PostExecute上更新视图…你能详细解释一下吗robbin？你认为
runOnUiThread（）NetworkOnMainThreadException@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_product_detail);
txtName = (TextView) findViewById(R.id.app_name);
txtVersion = (TextView) findViewById(R.id.app_version);
txtDesc = (TextView) findViewById(R.id.desc_app);
}
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
// product with this pid found
// Edit Text
txtName = (TextView) findViewById(R.id.app_name);
txtVersion = (TextView) findViewById(R.id.app_version);
txtDesc = (TextView) findViewById(R.id.desc_app);
pDialog.show();
}