！[在此处输入图像描述][1]我是Android的初学者，我正在使用后端 Parse.com 在我的应用程序中存储和检索信息。问题是我想检索带有姓名和职业的人员列表，但是我只能检索一个人的详细信息，我有多个人，但它在我的文本视图中只显示一条记录，我应该使用 listview，但我不明白适配器。我尝试在以下教程后实现，但它们不起作用。请告诉我如何在应用活动中检索多条记录或从 parse.com 动态加载文本视图。
显示数据活动仅显示 1 人的记录，但我有多个记录
public class ShowData extends ActionBarActivity {
Button Bsearch;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_show_data);
Parse.initialize(this, "keys", "keys");
// Uses a layout with a ListView (id: "listview"), which uses our Adapter.
Bsearch= (Button) findViewById(R.id.Bsearch);
Bsearch.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
ParseQuery<ParseObject> query = ParseQuery.getQuery("Pro");
query.whereEqualTo("City", "Pune");
query.getFirstInBackground(new GetCallback<ParseObject>() {
public void done(ParseObject emp, ParseException e) {
if (emp == null) {
Toast.makeText(ShowData.this,"Error", Toast.LENGTH_LONG).show();
} else {
String n =emp.getString("Name");
String prof= emp.getString("Professional");
//Toast.makeText(MainActivity.this,"User"+un+"n Password"+pwd,Toast.LENGTH_LONG).show();
TextView t = (TextView)findViewById(R.id.TVresult);
t.setText(""+n);
TextView t1 = (TextView) findViewById(R.id.TVresult1);
t1.setText("" + prof);
}
}
});
}
});
}
}
编辑的查询不起作用
Bsearch.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
ParseQuery<ParseObject> query = ParseQuery.getQuery("Pro");
query.whereEqualTo("City", "Pune");
query.findInBackground(new FindCallback<ParseObject>() {
public void done(List<ParseObject> emp, ParseException e) {
if (e == null) {
String n =emp.getString("Name");
String prof= emp.getString("Professional");
Toast.makeText(ShowData.this,"success", Toast.LENGTH_LONG).show();
TextView t = (TextView)findViewById(R.id.TVresult);
t.setText(""+n);
TextView t1 = (TextView) findViewById(R.id.TVresult1);
t1.setText("" + prof);
} else {
Log.d("score", "Error: " + e.getMessage());
}
}
});
}
});
https://i.stack.imgur.com/yxUqv.png
我设法修复了emp对象错误，但是当我点击搜索按钮应用程序崩溃时，不幸的是，我弹出了应用程序已停止在这里是logcat
04-24 18:39:34.208 4280-4280/com.example.sangram.nearbyapp E/Trace﹕ error opening trace file: No such file or directory (2)
04-24 18:39:34.432 4280-4280/com.example.sangram.nearbyapp E/ResourceType﹕ Style contains key with bad entry: 0x01010479
04-24 18:40:05.836 4280-4280/com.example.sangram.nearbyapp E/ResourceType﹕ Style contains key with bad entry: 0x01010479
04-24 18:40:08.397 4280-4280/com.example.sangram.nearbyapp E/ResourceType﹕ Style contains key with bad entry: 0x01010479
04-24 18:40:08.443 4280-4280/com.example.sangram.nearbyapp E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.sangram.nearbyapp/com.example.sangram.nearbyapp.ShowData}: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2211)
at android.app.ActivityThread.access$600(ActivityThread.java:149)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1300)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:153)
at android.app.ActivityThread.main(ActivityThread.java:5086)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:821)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:584)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
at android.app.ListActivity.onContentChanged(ListActivity.java:243)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:261)
at android.app.Activity.setContentView(Activity.java:1867)
at com.example.sangram.nearbyapp.ShowData.onCreate(ShowData.java:68)
at android.app.Activity.performCreate(Activity.java:5020)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2148)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2211)
at android.app.ActivityThread.access$600(ActivityThread.java:149)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1300)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:153)
at android.app.ActivityThread.main(ActivityThread.java:5086)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:821)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:584)
at dalvik.system.NativeStart.main(Native Method)
您正在调用getFirstInBackground，它将只返回一条记录。将查询更改为：
query.findInBackground(new FindCallback<ParseObject>() {
public void done(List<ParseObject> objects, ParseException e) {
if (e == null) {
objectsWereRetrievedSuccessfully(objects);
} else {
objectRetrievalFailed();
}
}
}
我想你想实现动态列表视图。您可以查看本教程。这将是有帮助的。
http://www.pcsalt.com/android/listview-using-baseadapter-android/
这应该有效，您只调用一个结果返回，并且您没有 for 循环来遍历对象。 我尝试编辑您的代码，看看并让我知道它是否有效：
public void updateMegaMillionsData() {
ParseQuery<GameDataParseClass> query = ParseQuery.getQuery("Pro");
query.whereEqualTo("City", "Pune");
query.getFirstInBackground(new GetCallback<ParseObject>() {
@Override
public void done(List<ParseObject> emp, ParseException e) {
if (emp != null) {
String n = String.valueOf(emp.get("Name"));
String prof= String.valueOf(emp.get("Professional"));
Toast.makeText(ShowData.this, "success", Toast.LENGTH_LONG).show();
TextView t = (TextView)findViewById(R.id.TVresult);
t.setText(""+n);
TextView t1 = (TextView) findViewById(R.id.TVresult1);
t1.setText("" + prof);
}
}
});
}