我想从存储在MySQL数据库中的URL加载Picasso中的图像。 但返回的代码是JSON，我不能让它工作。
当放置直接链接而不是TAG_IMAGE时，它会显示一个没有任何问题的图像（因此毕加索本身正在使用字符串）。
如何将JSON解析为字符串，以便Picasso可以加载它？
EDIT TAG_IMAGE需要转换为String（由Punit回答）。
码：
import ...
public class ViewRecipeActivity extends Activity {
TextView txtName;
TextView txtTime;
TextView txtPrice;
TextView txtDesc;
ImageView imagePhoto;
TextView txtCreatedAt;
String pid;
// Progress Dialog
private ProgressDialog pDialog;
// JSON parser class
JSONParser jsonParser = new JSONParser();
// single product url
private static final String url_recipe_details = "phpfiletoloadall.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_RECIPE = "recipes";
private static final String TAG_PID = "pid";
private static final String TAG_NAME = "name";
private static final String TAG_TIME = "time";
private static final String TAG_PRICE = "price";
private static final String TAG_IMAGE = "image";
private static final String TAG_DESCRIPTION = "description";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.view_recipe);
//toolbar back button
ImageView btnBack = findViewById( R.id.btnBack );
btnBack.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick (View view) {
startActivity(new Intent(ViewRecipeActivity.this, ActivityTwo.class));
finish();
}
}
);
BottomNavigationView bottomNavigationView = (BottomNavigationView) findViewById(R.id.bottomNavView_Bar);
BottomNavigationViewHelper.disableShiftMode(bottomNavigationView);
Menu menu = bottomNavigationView.getMenu();
MenuItem menuItem = menu.getItem(2);
menuItem.setChecked(true);
bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
switch (item.getItemId()){
case R.id.ic_home:
Intent intent0 = new Intent(ViewRecipeActivity.this, MainActivity.class);
startActivity(intent0);
finish();
break;
case R.id.ic_ingredients:
Intent intent1 = new Intent(ViewRecipeActivity.this, ActivityOne.class);
startActivity(intent1);
finish();
break;
case R.id.ic_dining:
break;
case R.id.ic_center_focus:
Intent intent3 = new Intent(ViewRecipeActivity.this, ActivityThree.class);
startActivity(intent3);
finish();
break;
case R.id.ic_backup:
Intent intent4 = new Intent(ViewRecipeActivity.this, ActivityFour.class);
startActivity(intent4);
finish();
break;
}
return false;
}
});
//Make network connect access (temp)
StrictMode.ThreadPolicy policy = new
StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
// Make textview scrollable
TextView textView = (TextView) findViewById(R.id.inputDesc);
textView.setMovementMethod(new ScrollingMovementMethod());
// getting product details from intent
Intent i = getIntent();
// getting product id (pid) from intent
pid = i.getStringExtra(TAG_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(ViewRecipeActivity.this);
pDialog.setMessage("Loading recipe 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_recipe_details, "GET", params);
// check your log for json response
Log.d("Single Recipe Details", json.toString());
// json success tag
success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// successfully received product details
JSONArray productObj = json
.getJSONArray(TAG_RECIPE); // 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.inputName);
txtDesc = (TextView) findViewById(R.id.inputDesc);
imagePhoto = (ImageView) findViewById( R.id.imagePhoto );
// display product data in EditText
txtName.setText(product.getString(TAG_NAME));
txtDesc.setText(product.getString(TAG_DESCRIPTION));
Picasso.get().load(TAG_IMAGE).into(imagePhoto);
Log.d("good", "shows recipe");
}else{
// product with pid not found
Log.d("bad", "recipe 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();
}
}
}
if (success == 1) {
// successfully received product details
JSONArray productObj = json
.getJSONArray(TAG_RECIPE); // 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.inputName);
txtDesc = (TextView) findViewById(R.id.inputDesc);
imagePhoto = (ImageView) findViewById( R.id.imagePhoto );
// display product data in EditText
txtName.setText(product.getString(TAG_NAME));
txtDesc.setText(product.getString(TAG_DESCRIPTION));
Picasso.get().load(product.getString(TAG_IMAGE)).into(imagePhoto);
Log.d("good", "shows recipe");
}
您正在使用TAG_IMAGE这是String变量名称的标签。因此，您必须使用此标记从json获取图像URL，就像获取名称TAG_NAME和描述TAG_DESCRIPTION一样。
获取图片网址
String imageUrl = product.getString(TAG_IMAGE);
Picasso.get().load(imageUrl).into(imagePhoto);
这很容易，
Picasso.with(this)
.load(TAG_IMAGE)
.error(R.mipmap.no_image_available)
.into(imagePhoto);
当你的图像没有加载，并得到一些错误时，显示错误部分
你可以使用它
Picasso.with(this)
.load(TAG_IMAGE)
.into(imagePhoto);