adding item to listView after passing info through

2020-05-07 01:46发布

I am trying to add an item, first by using an add button, then going to a different activity, then coming back to the original one and adding it in a listview. I can't seem to have more than one item.

AddScreen.class (My first activity):

    package com.painLogger;
    **IMPORTS**
    public class AddScreen extends Activity implements OnClickListener,
    OnItemClickListener {
/** Called when the activity is first created. */
Button addButton;
SimpleAdapter adapter;
List<HashMap<String, String>> painItems = new ArrayList<HashMap<String, String>>();
ListView listthings;
int[] to;
String[] from;
String painLevelString, timeOfPainString, textTreatmentString,
        painLocation, row1, row2;
TextView painTitle;
boolean myFirstTime;
int k;


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.addscreen);
    // if it's the first time opening the app, then go to 'AddMyInfo.class'
    SharedPreferences settings = this.getSharedPreferences("MyApp", 0);
    SharedPreferences.Editor e = settings.edit();
    boolean firstrun = settings.getBoolean("firstrun", true);
    if (firstrun) {
        e.putBoolean("firstrun", false);
        e.commit();
        Intent intent = new Intent(this, AddMyInfo.class);
        startActivity(intent);
    }
    //initialize painTitle and set its font
    painTitle = (TextView) findViewById(R.id.painTitle);
    Typeface font = Typeface.createFromAsset(getAssets(),
            "Chantelli_Antiqua.ttf");
    painTitle.setTypeface(font);
    listthings = (ListView) findViewById(R.id.listthings);
    from = new String[] { "row_1" + painItems.size(),
            "row_2" + painItems.size() };
    to = new int[] { R.id.row1, R.id.row2 };
    adapter = new SimpleAdapter(this, painItems, R.layout.mylistlayout,
            from, to);
    listthings.setAdapter(adapter);
    listthings.setOnItemClickListener(this);
    addButton = (Button) findViewById(R.id.addButton);
    addButton.setOnClickListener(this);

}

@Override
//on the activityresult,get the string extra, then add the item to the list
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
     if(this.getIntent().hasExtra("row1")){
     row1 = this.getIntent().getStringExtra("row1");
     row2 = this.getIntent().getStringExtra("row2");
     painLevelString = 
             this.getIntent().getStringExtra("com.painLogger.painLevel");
     painLocation = this.getIntent().getStringExtra("painLocation");
     timeOfPainString = 
             this.getIntent().getStringExtra("com.painLogger.painTime");
     textTreatmentString = 
             this.getIntent().getStringExtra("com.painLogger.treatment");
     addItem();
    }
}
 // to add the item, put it in the map, and add the map into the list
private void addItem() {
    HashMap<String, String> map = new HashMap<String, String>();
    map.put("row_1" + painItems.size(), row1);
    map.put("row_2" + painItems.size(), row2);
    painItems.add(map);
    adapter.notifyDataSetChanged();

}

public void onClick(View v) {
    // When '+' clicked, go to the PainLoggerActivity.java, where you can
    // click enter, and that sends those strings back to here, where I can
    // incorporate them into a list view, same as was there in the
    // PainLogger Activity

    Intent goToFields = new Intent (this, PainLoggerActivity.class);
    //put the desired extras into the intent
    startActivityForResult(goToFields, 1);


}

public void onItemClick(AdapterView<?> a, View v, int position, long id) {
    Intent intent = new Intent(this, Item1.class);
    intent.putExtra("com.painLogger.painLevel", painLevelString);
    intent.putExtra("com.painLogger.painTime", timeOfPainString);
    intent.putExtra("com.painLogger.treatment", textTreatmentString);
    intent.putExtra("painLocation", painLocation);
    startActivity(intent);
}

}  

My PainLoggerActivity, where I enter various info to be put into the list:

package com.painLogger; // imports public class PainLoggerActivity extends Activity implements OnClickListener, OnItemClickListener, OnKeyListener {

/** Called when the activity is first created. */
EditText txtItem, txtItem2, timeOfPain, textTreatment, painLevel;

Button btnAdd;
ListView listItems;
ArrayAdapter<String> aa;
List<HashMap<String, String>> painItems = new ArrayList<HashMap<String, String>>();
int[] to;
String[] from;
SimpleAdapter adapter;
String timeOfPainString, textTreatmentString, painLevelString, painLocation;
Spinner s;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    txtItem = (EditText) findViewById(R.id.txtItem);
    txtItem2 = (EditText) findViewById(R.id.txtItem2);
    timeOfPain = (EditText)findViewById(R.id.timeOfPain);
    textTreatment = (EditText)findViewById(R.id.textTreatment);
    painLevel = (EditText)findViewById(R.id.painLevel);

    btnAdd = (Button) findViewById(R.id.btnAdd);
    listItems = (ListView) findViewById(R.id.listItems);

    btnAdd.setOnClickListener(this);

    from = new String[] { "row_1", "row_2" };
    to = new int[] { R.id.row1, R.id.row2 };

    adapter = new SimpleAdapter(this, painItems,
            R.layout.mylistlayout, from, to);
    listItems.setAdapter(adapter);

    listItems.setOnItemClickListener(this);
    s = (Spinner) findViewById(R.id.spinner1);      
    ArrayAdapter<?>adapter = ArrayAdapter.createFromResource(
            this, R.array.planets, android.R.layout.simple_spinner_item);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    s.setAdapter(adapter);



}

private void addItem() {
    timeOfPainString = timeOfPain.getText().toString();
    textTreatmentString = textTreatment.getText().toString();
    painLevelString = s.getSelectedItem().toString();
    painLocation = txtItem.getText().toString();
    Intent intent = new Intent (this, AddScreen.class);
    intent.putExtra("com.painLogger.painLevel", painLevelString);
    intent.putExtra("com.painLogger.painTime", timeOfPainString);
    intent.putExtra("com.painLogger.treatment", textTreatmentString);
    intent.putExtra("painLocation", painLocation);
    setResult(1, intent);
    finish();

    HashMap<String, String> map = new HashMap<String, String>();
    map.put("row_1", txtItem.getText().toString());
    map.put("row_2", txtItem2.getText().toString());
    painItems.add(map);
    adapter.notifyDataSetChanged();


    }


public void onClick(View v) {
    if (v == this.btnAdd) {
        addItem();

    }

}

public boolean onKey(View v, int keyCode, KeyEvent event) {

    if (event.getAction() == KeyEvent.ACTION_DOWN
            && keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {
        this.addItem();

    }
    return false;

}

public void onItemClick(AdapterView<?> a, View v, int position, long id) {

        timeOfPainString = timeOfPain.getText().toString();
        textTreatmentString = textTreatment.getText().toString();
        painLevelString = s.getSelectedItem().toString();
        painLocation = txtItem.getText().toString();
        //create the intent
        Intent intent = new Intent (this, Item1.class);
        //put the desired extras into the intent
        intent.putExtra("com.painLogger.painLevel", painLevelString);
        intent.putExtra("com.painLogger.painTime", timeOfPainString);
        intent.putExtra("com.painLogger.treatment", textTreatmentString);
        intent.putExtra("pain location", painLocation);


        startActivity(intent);
        //set the variables to "", empty

}

}

My Item1.class is simply where the app goes when an item on the list is clicked. it has no other purpose.

I am having problem because when I add the item in the list, it replaces the previous one, and I am left with only one item.

2条回答
你好瞎i
2楼-- · 2020-05-07 02:33

Here is a tested prototype:

TestResultActivity.java

package com.arrdude.forumanswer;

import java.util.ArrayList;
import java.util.HashMap;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;

public class TestResultActivity extends Activity implements OnClickListener {
    private static final int REQUEST_LIST_ITEM = 235; //arbitrary request code
    static final String ADAPTER_VALUE_1 = "head";
    static final String ADAPTER_VALUE_2 = "sub";

    ArrayList<HashMap<String, String>> masterlist = null;
    ListAdapter adapter = null;

    ListView listview = null;
    Button addbutton = null;

    public ListAdapter getAdapter() {
        if(adapter == null){
            adapter = new SimpleAdapter(this, getMylist(), R.layout.listitem, new String[] {ADAPTER_VALUE_1, ADAPTER_VALUE_2}, new int[] {R.id.listheading, R.id.listsubheading});
        }
        return adapter;
    }

    public ListView getListview() {
        if(listview==null){
            listview = (ListView) findViewById(R.id.mainlistview);
            listview.setAdapter(getAdapter());
        }
        return listview;
    }

    public Button getAddbutton() {
        if(addbutton==null){
            addbutton = (Button) findViewById(R.id.mainaddbutton);
            addbutton.setClickable(true);
            addbutton.setOnClickListener(this);
        }
        return addbutton;
    }

    public ArrayList<HashMap<String, String>> getMylist() {
        if(masterlist==null){
            masterlist = new ArrayList<HashMap<String,String>>();
        }
        return masterlist;
    }

    public void addListItem(String head, String sub){
        HashMap<String, String> addme=new HashMap<String, String>();
        addme.put(ADAPTER_VALUE_1, head);
        addme.put(ADAPTER_VALUE_2, sub);

        masterlist.add(addme);
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        //lazy init objects not the most efficient in Android but easier reading
        getListview();
        getAddbutton();
        addListItem("Test Head", "Test sub heading here below"); //an initial item for testing
    }

    @Override
    public void onClick(View v) {
        Intent launchadditemI = new Intent(this, AddItemActivity.class);
        startActivityForResult(launchadditemI, REQUEST_LIST_ITEM);
    }

    @Override
    public void onActivityResult(int req, int res, Intent data){
        if(req == REQUEST_LIST_ITEM && res == RESULT_OK){
            String thishead = data.getStringExtra(ADAPTER_VALUE_1);
            String thissub = data.getStringExtra(ADAPTER_VALUE_2);
            addListItem(thishead, thissub);
        }
    }
}

AddItemActivity.java

package com.arrdude.forumanswer;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;

public class AddItemActivity extends Activity implements OnClickListener {
    EditText headeredittext = null;
    EditText subheadedittext = null;
    Button donebutton = null;
    Button cancelbutton = null;

    public EditText getHeaderedittext() {
        if(headeredittext==null){
            headeredittext = (EditText) findViewById(R.id.headedittext);
        }
        return headeredittext;
    }

    public EditText getSubheadedittext() {
        if(subheadedittext==null){
            subheadedittext = (EditText) findViewById(R.id.subedittext);
        }
        return subheadedittext;
    }

    public Button getDonebutton() {
        if(donebutton==null){
            donebutton = (Button) findViewById(R.id.adddonebutton);
            donebutton.setClickable(true);
            donebutton.setOnClickListener(this);
        }
        return donebutton;
    }

    public Button getCancelbutton() {
        if(cancelbutton==null){
            cancelbutton = (Button) findViewById(R.id.addcancelbutton);
            cancelbutton.setOnClickListener(this);
        }
        return cancelbutton;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.additem);
        //lazy init objects not the most efficient in Android but easier reading
        getHeaderedittext();
        getSubheadedittext();
        getDonebutton();
        getCancelbutton();
    }

    @Override
    public void onClick(View arg0) {
        switch (arg0.getId()) {
        case R.id.addcancelbutton:
            finish();
            break;

        case R.id.adddonebutton:
            sendResult();
            break;

        default:
            break;
        }
    }

    private void sendResult() {
        Intent resultI = new Intent();
        resultI.putExtra(TestResultActivity.ADAPTER_VALUE_1, getHeaderedittext().getText().toString());
        resultI.putExtra(TestResultActivity.ADAPTER_VALUE_2, getSubheadedittext().getText().toString());
        setResult(RESULT_OK, resultI);
        finish();
    }
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" android:text="@string/maintitle"/>
<ListView android:layout_height="wrap_content" android:layout_width="fill_parent" android:id="@+id/mainlistview"></ListView>
<Button android:id="@+id/mainaddbutton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/addbuttontext"></Button>
</LinearLayout>

additem.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">
    <LinearLayout android:layout_height="wrap_content" android:layout_width="fill_parent" android:id="@+id/LinearLayout01">
        <TextView android:layout_width="wrap_content" android:text="Header:" android:layout_height="wrap_content" android:id="@+id/TextView01"></TextView>
        <EditText android:layout_weight="1" android:layout_width="fill_parent" android:id="@+id/headedittext" android:layout_height="wrap_content">
            <requestFocus></requestFocus>
        </EditText>
    </LinearLayout>
    <LinearLayout android:layout_height="wrap_content" android:layout_width="fill_parent" android:id="@+id/linearLayout2">
        <TextView android:text="Subhead:" android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>
        <EditText android:layout_weight="1" android:layout_width="fill_parent" android:id="@+id/subedittext" android:layout_height="wrap_content"></EditText>
    </LinearLayout>
    <LinearLayout android:layout_height="wrap_content" android:layout_width="fill_parent" android:id="@+id/linearLayout1">
        <Button android:text="Cancel" android:id="@+id/addcancelbutton" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
        <Button android:text="Add Item" android:id="@+id/adddonebutton" android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
    </LinearLayout>

</LinearLayout>

listitem.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <TextView android:id="@+id/listheading" android:layout_width="wrap_content"
        android:layout_height="26dip" android:layout_alignParentTop="true"
        android:textSize="20sp" />
    <TextView android:id="@+id/listsubheading"
        android:layout_width="wrap_content" android:layout_height="22dip"
        android:layout_below="@id/listheading" android:textSize="16sp" />
</RelativeLayout>

strings.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="maintitle">List Items:</string>
    <string name="app_name">TestResultActivity</string>
    <string name="addbuttontext">Add New Item</string>
</resources>

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.arrdude.forumanswer"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="4" />

    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".TestResultActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".AddItemActivity"></activity>

    </application>
</manifest>

Happy coding!

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做自己的国王
3楼-- · 2020-05-07 02:45

First, Hashmap is suppose to be a collection, it seems you need only a pair of object, which, Map.Entry is far better solution (or even better, use a custom inner class).

Second, you add the item each time the addScreen Activity is created, and each time it is created, your painItems are freshly created. That's the reason you see only first content there, you need to have some way to persist your list (at least within application life cycle). Quick fix (though may not be desirable) is to put static:

private static List<Entry<String, String>> painItems = ....

should do the trick.

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