Question

我创建了一个列表视图。并添加了一个OnItemClickListener（）＆＃39;它。我传递了一个意图并通过意图传递了一些数据。

 contactListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
     @Override
     public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Intent intent = new Intent(MainActivity.this, ContactInfo.class);
            Contact ParseContactID = contactAdapter.getItem(position);

            intent.putExtra("ParseContactID", (Parcelable) ParseContactID);

            startActivity(intent);
     }
 });

我正在检索另一个班级的数据。

    Intent intent = getIntent();
    Bundle cBundle = intent.getExtras();

    String ContactInfo = cBundle.getString("ParseContactID");

但是当我尝试单击任何列表时，应用程序崩溃了。这是 image of the app和app crash

日志猫有一些致命的错误，不知道如何修复它们。

04-18 10:33:22.547 3528-3528/cm0573.contactsapp.user.contactsapp E/AndroidRuntime: FATAL EXCEPTION: main
                                                                               Process: cm0573.contactsapp.user.contactsapp, PID: 3528
                                                                               java.lang.ClassCastException: cm0573.contactsapp.user.contactsapp.Contact cannot be cast to android.os.Parcelable
                                                                                   at cm0573.contactsapp.user.contactsapp.MainActivity$4.onItemClick(MainActivity.java:135)
                                                                                   at android.widget.AdapterView.performItemClick(AdapterView.java:299)
                                                                                   at android.widget.AbsListView.performItemClick(AbsListView.java:1113)
                                                                                   at android.widget.AbsListView$PerformClick.run(AbsListView.java:2904)
                                                                                   at android.widget.AbsListView$3.run(AbsListView.java:3638)
                                                                                   at android.os.Handler.handleCallback(Handler.java:733)
                                                                                   at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                                   at android.os.Looper.loop(Looper.java:136)
                                                                                   at android.app.ActivityThread.main(ActivityThread.java:5017)
                                                                                   at java.lang.reflect.Method.invokeNative(Native Method)
                                                                                   at java.lang.reflect.Method.invoke(Method.java:515)
                                                                                   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
                                                                                   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
                                                                                   at dalvik.system.NativeStart.main(Native Method)

HELP！

Answer 1

在您的班级Contact中，它实现了Serializable。

public class Contact implements Serializable{ 

}

Answer 2

您正在将一个Contact对象放入Extra中，但在您解压缩时，您正试图获得String。 Contact对象和String对象不一样。正确？

您可以让您的Contact类实现Serializable接口，之后，您可以执行此操作。

Bundle bundle = new Bundle();
bundle.putSerializable("ParseContactID", ParseContactID);
intent.putExtras(bundle);

检索另一个类中的数据

Bundle bundle = getIntent().getExtras();
Contact  contact = (Contact)bundle.getSerializable("ParseContactID");

或者，如果您要实施parcelable，可以阅读This

public class ContactInfo extends AppCompatActivity {

TextView ContactInfoFamily_Name;
TextView ContactInfoFirst_Name;
TextView ContactInfoHouse_Number_ ;
TextView ContactInfoStreet_Name;
TextView ContactInfoTown_;
TextView ContactInfoCounty_;
TextView ContactInfoPost_Code;
TextView ContactInfoPhone_Number;
DatabaseHandler dbHandler = new DatabaseHandler(getApplicationContext());


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_contact_info);

    ContactInfoFamily_Name = (TextView) findViewById(R.id.ContactInfoFamilyName);
    ContactInfoFirst_Name = (TextView) findViewById(R.id.ContactInfoFirstName);
    ContactInfoHouse_Number_ = (TextView) findViewById(R.id.ContactInfoHouseNumber);
    ContactInfoStreet_Name = (TextView) findViewById(R.id.ContactInfoStreetName);
    ContactInfoTown_ = (TextView) findViewById(R.id.ContactInfoTown);
    ContactInfoCounty_ = (TextView) findViewById(R.id.ContactInfoCounty);
    ContactInfoPost_Code = (TextView) findViewById(R.id.ContactInfoPostCode);
    ContactInfoPhone_Number = (TextView) findViewById(R.id.ContactInfoPhone);


    Intent intent = getIntent();
    Bundle cBundle = intent.getExtras();

    Contact ContactInfo = (Contact) cBundle.getSerializable("ParseContactID");

    ContactInfoFamily_Name.setText(ContactInfo.getID());
    ContactInfoFirst_Name.setText(getIntent().getExtras().getString("FirstNameKey"));
    ContactInfoHouse_Number_.setText(getIntent().getExtras().getString("HouseNumberKey"));
    ContactInfoStreet_Name.setText(getIntent().getExtras().getString("StreetNameKey"));
    ContactInfoTown_.setText(getIntent().getExtras().getString("TownKey"));
    ContactInfoCounty_.setText(getIntent().getExtras().getString("CountyKey"));
    ContactInfoPost_Code.setText(getIntent().getExtras().getString("TownKey"));
    ContactInfoPhone_Number.setText(getIntent().getExtras().getString("PhoneNumberKey"));


}
}

Answer 3

确保您的Contact班级实施Parcelable。

public class Contact implements Parcelable {

    ...........
    ............... 
}

将Contact发送至ContactInfo活动，如下所示：

Intent intent = new Intent(MainActivity.this, ContactInfo.class);
Contact contact = contactAdapter.getItem(position);

intent.putExtra("ParseContactID", contact);
startActivity(intent);

检索Contact活动中的ContactInfo。

Contact contact = (Contact) getIntent().getParcelableExtra("ParseContactID");

关于使用Parcelable，<{3}}很好。

希望这会有所帮助〜

Answer 4

ContactInfo类 -

package cm0573.contactsapp.user.contactsapp;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

public class ContactInfo extends AppCompatActivity {

TextView ContactInfoFamily_Name = (TextView) findViewById(R.id.ContactInfoFamilyName);
TextView ContactInfoFirst_Name = (TextView) findViewById(R.id.ContactInfoFirstName);
TextView ContactInfoHouse_Number_ = (TextView) findViewById(R.id.ContactInfoHouseNumber);
TextView ContactInfoStreet_Name = (TextView) findViewById(R.id.ContactInfoStreetName);
TextView ContactInfoTown_ = (TextView) findViewById(R.id.ContactInfoTown);
TextView ContactInfoCounty_ = (TextView) findViewById(R.id.ContactInfoCounty);
TextView ContactInfoPost_Code = (TextView) findViewById(R.id.ContactInfoPostCode);
TextView ContactInfoPhone_Number = (TextView) findViewById(R.id.ContactInfoPhone);
DatabaseHandler dbHandler = new DatabaseHandler(getApplicationContext());


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_contact_info);

    Intent intent = getIntent();
    Bundle cBundle = intent.getExtras();

    Contact ContactInfo = (Contact) cBundle.getSerializable("ParseContactID");

    ContactInfoFamily_Name.setText(ContactInfo.getID());
    ContactInfoFirst_Name.setText(getIntent().getExtras().getString("FirstNameKey"));
    ContactInfoHouse_Number_.setText(getIntent().getExtras().getString("HouseNumberKey"));
    ContactInfoStreet_Name.setText(getIntent().getExtras().getString("StreetNameKey"));
    ContactInfoTown_.setText(getIntent().getExtras().getString("TownKey"));
    ContactInfoCounty_.setText(getIntent().getExtras().getString("CountyKey"));
    ContactInfoPost_Code.setText(getIntent().getExtras().getString("TownKey"));
    ContactInfoPhone_Number.setText(getIntent().getExtras().getString("PhoneNumberKey"));


}
}

单击列表视图时，应用程序崩溃！为什么？

4 个答案: