我在「return mFragmentList.get(position);」處得到不兼容類型的奇怪錯誤在MainActivity.java請幫助。

MainActivity.java

package com.pixalstudio.musicadda;

import android.os.Bundle;

import android.support.design.widget.TabLayout;

import android.support.v4.app.FragmentManager;

import android.support.v4.app.FragmentPagerAdapter;

import android.support.v4.view.ViewPager;

import android.support.v7.app.AppCompatActivity;

import android.widget.Toolbar;

import android.support.v4.app.Fragment;

import java.util.ArrayList;

import java.util.List;

public class MainActivity extends AppCompatActivity {

private Toolbar toolbar;

private TabLayout tabLayout;

private ViewPager viewPager;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

toolbar = (Toolbar) findViewById(R.id.toolbar);

setSupportActionBar(toolbar);

getSupportActionBar().setDisplayHomeAsUpEnabled(true);

viewPager = (ViewPager) findViewById(R.id.viewpager);

setupViewPager(viewPager);

tabLayout = (TabLayout) findViewById(R.id.tabs);

tabLayout.setupWithViewPager(viewPager);

}

private void setSupportActionBar(Toolbar toolbar) {

}

private void setupViewPager(ViewPager viewPager) {

ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());

adapter.addFragment(new OneFragment(), "ONE");

adapter.addFragment(new TwoFragment(), "TWO");

adapter.addFragment(new ThreeFragment(), "THREE");

viewPager.setAdapter(adapter);

}

class ViewPagerAdapter extends FragmentPagerAdapter {

private final List mFragmentList = new ArrayList<>();

private final List mFragmentTitleList = new ArrayList<>();

public ViewPagerAdapter(FragmentManager manager) {

super(manager);

}

@Override

public android.support.v4.app.Fragment getItem(int position) {

return mFragmentList.get(position);

}

@Override

public int getCount() {

return mFragmentList.size();

}

public void addFragment(android.app.Fragment fragment, String title) {

mFragmentList.add(fragment);

mFragmentTitleList.add(title);

}

@Override

public CharSequence getPageTitle(int position) {

return mFragmentTitleList.get(position);

}

}

}

如果任何人有什麼需要幫助，請讓我知道。 thanx提前:)

logcat的

03-04 21:38:22.643 2650-2650/com.pixalstudio.musicadda E/AndroidRuntime: FATAL EXCEPTION: main

Process: com.pixalstudio.musicadda, PID: 2650

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.pixalstudio.musicadda/com.pixalstudio.musicadda.MainActivity}: java.lang.ClassCastException: android.support.v7.widget.Toolbar cannot be cast to android.widget.Toolbar

at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)

at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)

at android.app.ActivityThread.access$800(ActivityThread.java:151)

at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)

at android.os.Handler.dispatchMessage(Handler.java:102)

at android.os.Looper.loop(Looper.java:135)

at android.app.ActivityThread.main(ActivityThread.java:5254)

at java.lang.reflect.Method.invoke(Native Method)

at java.lang.reflect.Method.invoke(Method.java:372)

at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

Caused by: java.lang.ClassCastException: android.support.v7.widget.Toolbar cannot be cast to android.widget.Toolbar

at com.pixalstudio.musicadda.MainActivity.onCreate(MainActivity.java:26)

at android.app.Activity.performCreate(Activity.java:5990)

at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)

at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)

at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)

at android.app.ActivityThread.access$800(ActivityThread.java:151)

at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)

at android.os.Handler.dispatchMessage(Handler.java:102)

at android.os.Looper.loop(Looper.java:135)

at android.app.ActivityThread.main(ActivityThread.java:5254)

at java.lang.reflect.Method.invoke(Native Method)

at java.lang.reflect.Method.invoke(Method.java:372)

at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)

at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

03-04 21:38:22.645 1519-1887/system_process W/ActivityManager: Force finishing activity 1 com.pixalstudio.musicadda/.MainA

ctivity

的build.gradle

apply plugin: 'com.android.application'

android {

compileSdkVersion 23

buildToolsVersion "23.0.1"

defaultConfig {

applicationId "com.pixalstudio.musicadda"

minSdkVersion 14

targetSdkVersion 23

versionCode 1

versionName "1.0"

}

buildTypes {

release {

minifyEnabled false

proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'

}

}

}

dependencies {

compile fileTree(dir: 'libs', include: ['*.jar'])

testCompile 'junit:junit:4.12'

compile 'com.android.support:appcompat-v7:23.2.0'

compile 'com.android.support:design:23.2.0'

compile 'com.android.support:support-v4:23.2.0'

}