Question

我从parse.com Android开发者指南中获取了此代码：

@Override
public View getItemView(ParseObject object, View v, ViewGroup parent) {
  if (v == null) {
    v = View.inflate(getContext(), R.layout.adapter_item, null);
  }

  // Take advantage of ParseQueryAdapter's getItemView logic for
  // populating the main TextView/ImageView.
  // The IDs in your custom layout must match what ParseQueryAdapter expects
  // if it will be populating a TextView or ImageView for you.
  super.getItemView(object, v, parent);

  // Do additional configuration before returning the View.
  TextView descriptionView = (TextView) v.findViewById(R.id.description);
  descriptionView.setText(object.getString("description"));
  return v;
}

但是，(ParseObject object, View v, ViewGroup parent)有三个错误：

Cannot resolve symbol "Object"
Cannot resolve symbol "v"
Cannot resolve symbol"parent"

当然，我知道我必须在某处定义object，v和parent。但是哪里？什么是PaseObject object，View v，ViewGroup parent？我如何以及在何处定义它们？我在我的应用程序中正在做的是：

我有一个ParseQueryAdapter，我想自定义它
我想通过添加description textView来自定义它，并使字体大小更大。我添加了布局和一切。现在我想要代码。

那么，基本上，我在哪里以及如何定义(ParseObject object, View v, ViewGroup parent)？ 注意：我有解析库和所有内容;我可以使用ParseObject等 编辑：Build.Gradle：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.2"

    defaultConfig {
        applicationId "com.alibdeir.signupactivity"
        minSdkVersion 17
        targetSdkVersion 21
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}


dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile "com.android.support:appcompat-v7:23.0.+"
    compile 'com.parse.bolts:bolts-android:1.+'
    compile 'com.parse:parse-android:1.+'
    compile 'com.android.support:design:23.+'
    compile 'com.baoyz.swipemenulistview:library:1.3.0'
    compile 'com.parse:parseui-widget-android:0.0.1'
    compile 'com.android.support:recyclerview-v7:23.0.0-rc1'
}

另一个编辑：我知道我犯的是一个非常蹩脚的错误，但是，如果你有答案，请回答。即使你必须详细说明。这将是伟大的如果我可以完成我正在努力的应用程序的这个屏幕 完整来源：

        package com.alibdeir.signupactivity;

    import android.app.AlertDialog;
    import android.app.Dialog;
    import android.app.ProgressDialog;
    import android.content.Context;
    import android.content.DialogInterface;
    import android.content.Intent;
    import android.os.Bundle;
    import android.support.v7.app.AppCompatActivity;
    import android.support.v7.widget.Toolbar;
    import android.util.Log;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.AdapterView;
    import android.widget.ListView;
    import android.widget.TextView;
    import android.widget.Toast;

    import com.parse.FindCallback;
    import com.parse.GetDataCallback;
    import com.parse.LogOutCallback;
    import com.parse.ParseClassName;
    import com.parse.ParseException;
    import com.parse.ParseFile;
    import com.parse.ParseImageView;
    import com.parse.ParseObject;
    import com.parse.ParseQuery;
    import com.parse.ParseQueryAdapter;
    import com.parse.ParseUser;

    import java.util.ArrayList;
    import java.util.List;

    public class MainActivity extends AppCompatActivity {
    ParseUser user = ParseUser.getCurrentUser();
    private Dialog progressDialog;
    ListView list;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        //region emailNotVerified
        if (user.getBoolean("emailVerified") == false) {
            Intent goBackToLogin = new Intent(MainActivity.this, LoginActivity.class);
            MainActivity.this.startActivity(goBackToLogin);
            Toast.makeText(getApplicationContext(), "Please verify your email", Toast.LENGTH_SHORT).show();
            finish();
        }
        //endregion
        else {
            setContentView(R.layout.activity_main);
            Toolbar myToolbar = (Toolbar) findViewById(R.id.my_toolbar);
            setSupportActionBar(myToolbar);
            list = (ListView) findViewById(R.id.list);
            ParseQueryAdapter<ParseObject> titles = new ParseQueryAdapter<ParseObject>(this, "Campaign");
            titles.setTextKey("Title");
            titles.setImageKey("Picture");

        }
        @Override
        public View getItemView(ParseObject object, View v, ViewGroup parent) {

            if (v == null) {
                v = View.inflate(getContext(), R.layout.list_single, null);
            }

            super.getItemView(meal, v, parent);

            ParseImageView mealImage = (ParseImageView) v.findViewById(R.id.icon);
            ParseFile photoFile = meal.getParseFile("photo");
            if (photoFile != null) {
                mealImage.setParseFile(photoFile);
                mealImage.loadInBackground(new GetDataCallback() {
                    @Override
                    public void done(byte[] data, ParseException e) {
                        // nothing to do
                    }
                });
            }

            TextView titleTextView = (TextView) v.findViewById(R.id.text1);
            titleTextView.setText(meal.getTitle());
            TextView ratingTextView = (TextView) v
                    .findViewById(R.id.favorite_meal_rating);
            ratingTextView.setText(meal.getRating());
            return v;
        }







            // Take advantage of ParseQueryAdapter's getItemView logic for
            // populating the main TextView/ImageView.




        }


//        Toolbar myToolbar = (Toolbar) findViewById(R.id.my_toolbar);
//        setSupportActionBar(myToolbar);


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
//        MenuInflater  menuInflater = getMenuInflater();
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return super.onCreateOptionsMenu(menu);

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        super.onOptionsItemSelected(item);
        switch (item.getItemId()) {
            case R.id.action_logout:
                openAlert();

                break;



        }
        return super.onOptionsItemSelected(item);
    }

    private void openAlert() {
        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(MainActivity.this);
        alertDialogBuilder.setTitle("Confirm your logout")
                .setMessage("Are you sure you want to log out?");
        alertDialogBuilder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int id) {
                // Positive OnClick to log out
                showProgressBar("Logging Out");
                ParseUser.logOutInBackground(new LogOutCallback() {
                    @Override
                    public void done(ParseException e) {
                        if (e == null) {
                            //Success
                            dismissProgressBar();
                            Intent startLogin = new Intent(MainActivity.this, LoginActivity.class);
                            MainActivity.this.startActivity(startLogin);
                            finish();
                        } else {
                            //Sign up did not succeed.
                            dismissProgressBar();
                            Toast.makeText(getApplicationContext(), "An unknown error occurred while logging out", Toast.LENGTH_SHORT).show();

                        }
                    }
                });
                ParseUser currentUser = ParseUser.getCurrentUser();
            }
        });
        alertDialogBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int id) {
                // Cancel
            }
        });
        alertDialogBuilder.setCancelable(false);
        AlertDialog alertDialog = alertDialogBuilder.create();
        // show alert
        alertDialog.show();
    }

    public void showProgressBar(String msg) {
        progressDialog = ProgressDialog.show(this, "Logging out", "Loading", true);
    }

    public void dismissProgressBar() {
        if (progressDialog != null && progressDialog.isShowing())
            progressDialog.dismiss();
    }

}


**Don't worry about the file names and IDs, they are all correct**

Answer 1

在方法定义中已经定义了变量，例如这样：

public View getItemView(ParseObject object, View v, ViewGroup parent)

是声明这些变量的内容。如果您收到的错误是未定义的，则必须是因为您尝试从getItemView（）方法外部访问它们，或者在实际代码中重命名它们。

如果您的更新显示了定义此功能的类的完整源代码，则问题很明显：

您尝试覆盖的getItemView方法不是AppCompatActivity定义的方法 - 它是ParseQueryAdapter的方法。我不知道你是如何在这种情况下结束的，但这种方法在该课程中无法奏效。必须将其移至继承自ParseQueryAdapter。

的新类

所以，你需要有一个类，让我们说它是一个Campaign，你需要用你的ParseQueryAdapter子类化这样的东西：

 import android.content.Context;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.TextView;


import com.parse.GetDataCallback;
import com.parse.ParseClassName;
import com.parse.ParseException;
import com.parse.ParseFile;
import com.parse.ParseImageView;
import com.parse.ParseObject;
import com.parse.ParseUser;

/**
 * Created by AbAppletic on 12/15/2015.
 */
@ParseClassName("Campaign")

public class Campaign extends ParseObject {
    public Campaign() {
        // default Constructor
    }

    public String getTitle() {
        return getString("Title");
//get the title
    }

    public String getDescription(){
//get the description
        return getString("Description");
    }

    public ParseUser getAuthor() {
// get the author
        return getParseUser("Owner");
    }


    public ParseFile getImage() {
//get the image
        return getParseFile("Picture");
    }
}

而且，现在，你必须创建一个新的类

ParseQueryAdapter<Campaign>
// Campaign is the class we previously created

因此，在您的情况下，您将在此处设置自定义布局中的图像，说明和标题：

public class mainAdapter extends ParseQueryAdapter<Campaign> {
public mainAdapter(Context context){
    super(context,new ParseQueryAdapter.QueryFactory<Campaign>(){
        public ParseQuery<Campaign> create(){
            ParseQuery query = new ParseQuery("Campaign");
            query.orderByDescending("updatedAt");
            return query;
        }
    });
}
@Override
public View getItemView(Campaign campaign, View v, ViewGroup parent) {

    if (v == null) {
        v = View.inflate(getContext(), R.layout.list_single, null);
    }

    super.getItemView(campaign, v, parent);

    ParseImageView campaignImage = (ParseImageView) v.findViewById(R.id.icon);
    ParseFile photoFile = campaign.getParseFile("Picture");
    if (photoFile != null) {
        campaignImage.setParseFile(photoFile);

        campaignImage.loadInBackground(new GetDataCallback() {
            @Override
            public void done(byte[] data, ParseException e) {
                // nothing to do
            }
        });
    }

    TextView titleTextView = (TextView) v.findViewById(R.id.title);
    titleTextView.setText(campaign.getTitle());
    TextView descriptionTextView = (TextView) v
            .findViewById(R.id.description);
    descriptionTextView.setText(campaign.getDescription());
    return v;

}

} 现在，在您的MainActivity中：定义这个：

    private mainAdapter adapter;
// mainAdapter is the name of the class we just created that extends ParseQueryAdapter

然后，在onCreate()中，只需将适配器设置为listView：

即可

adapter = new mainAdapter(this);
            list.setAdapter(adapter);

在Parse.initialize之上：

ParseObject.registerSubclass(Campaign.class);

Campaign是我们刚刚创建的第一个类。

无法解析符号“Object”，“v”，“parent”（parse.com getItemView（））

1 个答案: