我在列表视图活动中创建了一个工具栏。我使用了以下代码：
public class Home extends ListActivity {
private ProgressDialog pDialog;
// URL to get contacts JSON
private static String url = "http://api-11hr.anovatesoft.com/v1/list";
// JSON Node names
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_USERNAME = "username";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_ADDRESS = "address";
private static final String TAG_CONTACT_NUMBER = "contactnumber";
private static final String TAG_POSTAL_CODE = "postalcode";
private static final String TAG_IMAGE = "image";
SessionManager session;
private double latitude;
private double longitude;
private String apikey;
private String status;
GPSTracker gps;
private Toolbar toolbar; // Declaring the Toolbar Object
// contacts JSONArray
JSONArray contacts = null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home);
toolbar = (Toolbar) findViewById(R.id.tool_bar); // Attaching the layout to the toolbar object
setActionBar(toolbar); // Setting toolbar as the ActionBar with setSupportActionBar() call
// get action bar
/* ActionBar actionBar = getActionBar();
getActionBar().setHomeButtonEnabled(true);
actionBar.setDisplayHomeAsUpEnabled(true);*/
AlertDialog.Builder alertDialog2 = new AlertDialog.Builder(
Home.this);
// Setting Dialog Title
alertDialog2.setTitle("Too quiet?");
// Setting Dialog Message
alertDialog2.setMessage("Follow your favourite merchants and see what deals they're launching at the 11th Hour!");
// Setting Positive "Yes" Btn
alertDialog2.setPositiveButton("YES",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// Write your code here to execute after dialog
dialog.cancel();
}
});
alertDialog2.show();
Gps_func();
// Session class instance
session = new SessionManager(getApplicationContext());
// get user data from session
HashMap<String, String> user = session.getUserDetails();
// apikey
// Calling Application class (see application tag in AndroidManifest.xml)
final GlobalClass globalVariable = (GlobalClass) getApplicationContext();
//Set name and email in global/application context
apikey = globalVariable.getApikey();
latitude = globalVariable.getLatitude();
longitude = globalVariable.getLongitude();
status = globalVariable.getStatus();
contactList = new ArrayList<HashMap<String, String>>();
ListView lv = getListView();
// Listview on item click listener
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String cost = ((TextView) view.findViewById(R.id.email))
.getText().toString();
// Starting single contact activity
Intent in = new Intent(getApplicationContext(),
Adds.class);
in.putExtra(TAG_EMAIL, cost);
startActivity(in);
}
});
// Calling async task to get json
new GetContacts().execute();
}
private void Gps_func() {
gps = new GPSTracker(Home.this);
// check if GPS enabled
if (gps.canGetLocation()) {
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
// \n is for new line
// Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
Log.d("tag", "Longitude:\n" + longitude + "\n Latitude: \n" + latitude);
} else {
// can't get location
// GPS or Network is not enabled
// Ask user to enable GPS/network in settings
gps.showSettingsAlert();
if (gps.canGetLocation()) {
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
// \n is for new line
// Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
Log.d("tag", "Longitude:\n" + longitude + "\n Latitude: \n" + latitude);
}
}
}
@Override
protected void onRestart() {
super.onRestart();
Gps_func();
}
/**
* Async task class to get json by making HTTP call
*/
private class GetContacts extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(Home.this);
pDialog.setMessage("Please wait....");
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler1 sh = new ServiceHandler1(apikey, latitude, longitude);
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler1.POST);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
contacts = jsonObj.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
String username = c.getString(TAG_USERNAME);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_CONTACT_NUMBER);
String postalcode = c.getString(TAG_POSTAL_CODE);
// tmp hashmap for single contact
HashMap<String, String> contact = new HashMap<String, String>();
// adding each child node to HashMap key => value
contact.put(TAG_EMAIL, email);
// adding contact to contact list
contactList.add(contact);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
Home.this, contactList,
R.layout.list_item1, new String[]{TAG_EMAIL,
}, new int[]{
R.id.email,});
setListAdapter(adapter);
}
}
@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();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
但是当我运行应用程序时，它会出错：
java.lang.NoClassDefFoundError：android.widget.Toolbar
请帮我拿出工具栏
apply plugin: 'com.android.application'
android {
compileSdkVersion 22
buildToolsVersion "22.0.1"
defaultConfig {
applicationId "com.example.kmi_dev.fbloginsample"
minSdkVersion 11
targetSdkVersion 22
versionCode 1
versionName "1.0"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
repositories {
mavenCentral()
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:appcompat-v7:22.2.0'
compile 'com.facebook.android:facebook-android-sdk:4.1.0'
}
tool_bar.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/ColorPrimary"
android:theme="@style/ThemeOverlay.AppCompat.Dark"
android:elevation="4dp"
>
</android.support.v7.widget.Toolbar>
列表布局包括tool_bar.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<!-- Main ListView
Always give id value as list(@android:id/list)
-->
<include
android:id="@+id/tool_bar"
layout="@layout/tool_bar"
></include>
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
答案 0 :(得分：4)
此错误表示您要转换Toolbar R.id.tool_bar。在您的布局中，Toolbar为android.support.v7.widget.Toolbar，但在Home中，您希望将其投放到android.widget.Toolbar。因此，请检查导入，确保导入的Toolbar为android.support.v7.widget.Toolbar。
P.S.：如果它不起作用，清理或重建你的项目。
答案 1 :(得分：1)
工具栏包含在支持库中。直到我的知识工具栏应该从
导入android.support.v7.widget.Toolbar
不是这个
android.widget.Toolbar
所以我想请你在build.gradle中添加V7支持库的工具栏：
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
// Android Support Libraries
compile 'com.android.support:appcompat-v7:22.2.0'
}
答案 2 :(得分：1)
首先，进行任何布局，然后在其中放置该工具栏。
使用27 SDK不要使用修订版28.0.0 Alphas版本，它有一个我遇到的错误。 如果您想使用最新的SDK，请在alphas之后使用beta版本，例如beta。 稳定版本之后，就可以使用了。
答案 3 :(得分：0)
如果您使用API级别＆lt; 21在设备上你应该使用支持库中的android.support.v7.widget.Toolbar
答案 4 :(得分：0)
根据Java文档java.lang.NoClassDefFoundError:是Runtime error而不是compileTimeError。而error只是因为你的类能够在编译时找到但在程序执行时（运行模式）此课程未由virtual machine查找。因此，现在已清除您的必修课在compile()时找到，但在execute()时找不到。
享受你的代码：） -