Question

错误是引起：java.lang.NullPointerException：尝试调用虚方法＆＃39; void android.widget.RelativeLayout.setOnClickListener（android.view.View $ OnClickListener）＆＃39;在空对象引用上

我的java是

package com.doctorfinderapp.doctorfinder;

import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.RelativeLayout;

public class DoctorProfileActivity extends AppCompatActivity {



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

        //get data from previous activity
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Invia una mail a Dottore", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();


            }
        });

        //vado sul feed
        RelativeLayout feedback = (RelativeLayout) findViewById(R.id.feedback);
        feedback.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(DoctorProfileActivity.this, FeedbackItemActivity.class);
                startActivity(intent);
            }
        });
    }

}

xml代码，其中声明了函数＆＃34; feedbackfunction＆＃34;

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginTop="@dimen/activity_horizontal_margin"
    android:padding="@dimen/activity_horizontal_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.letsnurture.ln_202.coordinatorlayoutpart1.ScrollingActivity"
    tools:showIn="@layout/activity_scrolling">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:weightSum="1">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="74dp"
            android:background="?attr/selectableItemBackground"
            android:clickable="true"
            android:padding="@dimen/activity_horizontal_margin"
            android:layout_weight="0.61">

            <ImageView
                android:id="@+id/ivContactItem1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginEnd="@dimen/activity_horizontal_margin"
                android:layout_marginRight="@dimen/activity_horizontal_margin"
                android:src="@drawable/ic_account_circle_black_24dp" />

            <TextView
                android:id="@+id/tvNumber1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:layout_toEndOf="@id/ivContactItem1"
                android:layout_toRightOf="@id/ivContactItem1"
                android:text="Lorenzo Gitto"
                android:textAppearance="@style/TextAppearance.AppCompat.Medium"
                android:textColor="#212121" />


            <ToggleButton
                android:id="@+id/chkState1"
                android:layout_width="24dp"
                android:layout_height="24dp"
                android:layout_alignParentEnd="true"
                android:layout_alignParentRight="true"
                android:layout_centerVertical="true"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:background="@drawable/ic_account_circle_white_24dp"
                android:checked="true"
                android:padding="6dp"
                android:textOff=""
                android:textOn="" />

        </RelativeLayout>

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/selectableItemBackground"
            android:clickable="true"
            android:padding="@dimen/activity_horizontal_margin">

            <ImageView
                android:id="@+id/ivContactItem2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginEnd="@dimen/activity_horizontal_margin"
                android:layout_marginRight="@dimen/activity_horizontal_margin"
                android:src="@drawable/ic_info_black_24dp"
                android:visibility="visible" />

            <TextView
                android:id="@+id/tvNumber2"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:layout_toEndOf="@id/ivContactItem2"
                android:layout_toRightOf="@id/ivContactItem2"
                android:text="Chirurgia Toracica"
                android:textAppearance="@style/TextAppearance.AppCompat.Medium"
                android:textColor="#212121" />

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_below="@id/tvNumber2"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:layout_marginTop="8dp"
                android:layout_toEndOf="@id/ivContactItem2"
                android:layout_toRightOf="@id/ivContactItem2"
                android:text="Chirurgia Vascolare"
                android:textAppearance="@style/TextAppearance.AppCompat.Small"
                android:textColor="#727272" />

            <ToggleButton
                android:id="@+id/chkState2"
                android:layout_width="24dp"
                android:layout_height="24dp"
                android:layout_alignParentEnd="true"
                android:layout_alignParentRight="true"
                android:layout_centerVertical="true"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:background="@drawable/ic_info_white_24dp"
                android:checked="false"
                android:padding="6dp"
                android:textOff=""
                android:textOn="" />

        </RelativeLayout>

        <include layout="@layout/item_divider" />

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/selectableItemBackground"
            android:clickable="true"
            android:padding="@dimen/activity_horizontal_margin">

            <ImageView
                android:id="@+id/ivContactItem3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginEnd="@dimen/activity_horizontal_margin"
                android:layout_marginRight="@dimen/activity_horizontal_margin"
                android:src="@drawable/ic_book_black_24dp" />

            <TextView
                android:id="@+id/tvNumber3"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:layout_toEndOf="@id/ivContactItem3"
                android:layout_toLeftOf="@+id/chkState3"
                android:layout_toRightOf="@id/ivContactItem3"
                android:layout_toStartOf="@+id/chkState3"
                android:ellipsize="end"
                android:maxLines="1"
                android:text="Anni di esperienza: "
                android:textAppearance="@style/TextAppearance.AppCompat.Medium"
                android:textColor="#212121" />

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_below="@id/tvNumber3"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:layout_marginTop="8dp"
                android:layout_toEndOf="@id/ivContactItem3"
                android:layout_toRightOf="@id/ivContactItem3"
                android:text="11"
                android:textAppearance="@style/TextAppearance.AppCompat.Small"
                android:textColor="#727272" />

            <ToggleButton
                android:id="@+id/chkState3"
                android:layout_width="24dp"
                android:layout_height="24dp"
                android:layout_alignParentEnd="true"
                android:layout_alignParentRight="true"
                android:layout_centerVertical="true"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:background="@drawable/ic_info_white_24dp"
                android:checked="true"
                android:padding="6dp"
                android:textOff=""
                android:textOn="" />

        </RelativeLayout>

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/selectableItemBackground"
            android:clickable="true"
            android:padding="@dimen/activity_horizontal_margin">

            <ImageView
                android:id="@+id/ivContactItem4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginEnd="@dimen/activity_horizontal_margin"
                android:layout_marginRight="@dimen/activity_horizontal_margin"
                android:src="@drawable/ic_explore_black_24dp"
                android:visibility="visible" />

            <TextView
                android:id="@+id/tvNumber4"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:layout_toEndOf="@id/ivContactItem4"
                android:layout_toLeftOf="@+id/chkState4"
                android:layout_toRightOf="@id/ivContactItem4"
                android:layout_toStartOf="@+id/chkState4"
                android:ellipsize="end"
                android:maxLines="1"
                android:text="Luogo di lavoro"
                android:textAppearance="@style/TextAppearance.AppCompat.Medium"
                android:textColor="#212121" />

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_below="@id/tvNumber4"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:layout_marginTop="8dp"
                android:layout_toEndOf="@id/ivContactItem4"
                android:layout_toRightOf="@id/ivContactItem4"
                android:text="Via del Porto, 21"
                android:textAppearance="@style/TextAppearance.AppCompat.Small"
                android:textColor="#727272" />

            <ToggleButton
                android:id="@+id/chkState4"
                android:layout_width="24dp"
                android:layout_height="24dp"
                android:layout_alignParentEnd="true"
                android:layout_alignParentRight="true"
                android:layout_centerVertical="true"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:background="@drawable/ic_info_white_24dp"
                android:padding="6dp"
                android:textOff=""
                android:textOn="" />

        </RelativeLayout>

        <include layout="@layout/item_divider" />

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/selectableItemBackground"
            android:clickable="true"
            android:onClick="feedbackfunction"
            android:padding="@dimen/activity_horizontal_margin">

            <ImageView
                android:id="@+id/ivContactItem5"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginEnd="@dimen/activity_horizontal_margin"
                android:layout_marginRight="@dimen/activity_horizontal_margin"
                android:src="@drawable/ic_exit_to_app_white_24dp" />

            <TextView
                android:id="@+id/tvNumber5"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:layout_toEndOf="@id/ivContactItem5"
                android:layout_toLeftOf="@+id/chkState5"
                android:layout_toRightOf="@id/ivContactItem5"
                android:layout_toStartOf="@+id/chkState5"
                android:ellipsize="end"
                android:maxLines="1"
                android:text="Punteggio Feedback"
                android:clickable="true"
                android:textAppearance="@style/TextAppearance.AppCompat.Medium"
                android:textColor="#212121"
                />

            <ToggleButton
                android:id="@+id/chkState5"
                android:layout_width="24dp"
                android:layout_height="24dp"
                android:layout_alignParentEnd="true"
                android:layout_alignParentRight="true"
                android:layout_centerVertical="true"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:background="@drawable/ic_book_white_24dp"
                android:checked="true"
                android:padding="6dp"
                android:textOff=""
                android:textOn="" />

        </RelativeLayout>

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:background="?attr/selectableItemBackground"
            android:clickable="true"
            android:padding="@dimen/activity_horizontal_margin">

            <ImageView
                android:id="@+id/ivContactItem6"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_centerVertical="true"
                android:layout_marginEnd="@dimen/activity_horizontal_margin"
                android:layout_marginRight="@dimen/activity_horizontal_margin"
                android:src="@drawable/ic_book_black_24dp"
                android:visibility="visible" />

            <TextView
                android:id="@+id/tvNumber6"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:layout_toEndOf="@id/ivContactItem6"
                android:layout_toLeftOf="@+id/chkState6"
                android:layout_toRightOf="@id/ivContactItem6"
                android:layout_toStartOf="@+id/chkState6"
                android:ellipsize="end"
                android:maxLines="1"
                android:text="Ulteriori info"
                android:textAppearance="@style/TextAppearance.AppCompat.Medium"
                android:textColor="#212121" />

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_below="@id/tvNumber6"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:layout_marginTop="8dp"
                android:layout_toEndOf="@id/ivContactItem6"
                android:layout_toRightOf="@id/ivContactItem6"
                android:maxLines="10"
                android:text="Vai Su linkedin per vedere le mie info e competenze...http://www.linkedin.com/NomeDottore  "
                android:textAppearance="@style/TextAppearance.AppCompat.Small"
                android:textColor="#727272" />

            <ToggleButton
                android:id="@+id/chkState6"
                android:layout_width="24dp"
                android:layout_height="24dp"
                android:layout_alignParentEnd="true"
                android:layout_alignParentRight="true"
                android:layout_centerVertical="true"
                android:layout_marginLeft="@dimen/activity_horizontal_margin"
                android:layout_marginStart="@dimen/activity_horizontal_margin"
                android:background="@drawable/ic_exit_to_app_white_24dp"
                android:padding="6dp"
                android:textOff=""
                android:textOn="" />

        </RelativeLayout>

        <include layout="@layout/item_divider" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:padding="@dimen/activity_horizontal_margin">

            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Prenota appuntamento"
                />

            <Button
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginBottom="@dimen/activity_horizontal_margin"
                android:layout_marginTop="@dimen/activity_horizontal_margin"
                android:text="Videochiama"
                />
        </LinearLayout>
    </LinearLayout>

</android.support.v4.widget.NestedScrollView>

有人能帮帮我吗？感谢所有

Answer 1

你没有id等于反馈的任何RelativeLayout。

RelativeLayout feedback = (RelativeLayout) findViewById(R.id.feedback);

因此，您的反馈对象为空，并且您无法在空对象上执行onClick事件

解决方案

设置RelativeLayout id = feedback

Answer 2

您似乎没有为@id设置RelativeLayout：

 android:id="@+id/feedback"

由以下引起：java.lang.NullPointerException：-...在null对象引用上

2 个答案: