java - 无法解析方法getSupportFragmentManager()

Question

我发现消息无法解析方法“getSupportFragmentManager()”，我想在 Activity 中添加片段

这是我的代码

package com.formation.testfragment;

import android.app.Activity;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v7.app.*;

import android.support.v4.app.FragmentTransaction;
import android.os.Bundle;

public class MainActivity extends Activity {

    private FragmentManager fragmentManager;


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

        fragmentManager = getSupportFragmentManager();
    }
}

这是我的build.gradle

应用插件:“com.android.application”

android {


    compileSdkVersion 27
    defaultConfig {
        applicationId "com.formation.testfragment"
        minSdkVersion 17
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    repositories {
        mavenCentral()
    }


}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support.constraint:constraint-layout:1.1.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

    compile 'com.android.support:support-v4:27.1.1'
}

但是找不到方法getSupportFragmentManager()。
谢谢。

Answer 1

getSupportFragmentManager()是FragmentActivity的一种方法。您需要直接或间接(例如，通过扩展AppCompatActivity)从中继承。

在您的情况下，考虑到您的依赖关系，您可以直接扩展FragmentActivity:

public class MainActivity extends FragmentActivity