You may check if you are sending clearText through HTTP Fix : https://medium.com/@son.rommer/fix-cleartext-traffic-error-in-android-9-pie-2f4e9e2235e6 OR In the Case of Apache HTTP client deprecation (From Google ) : With Android 6.0, we removed support for the Apache HTTP client. Beginning with Android 9, that library is removed from the bootclasspath and is not available to apps by default. To continue using the Apache HTTP client, apps that target Android 9 and above can add the following to their AndroidManifest.xml:

源 https://developer.android.com/about/versions/pie/android-9.0-changes-28

实现这一点的简单方法是使用这个属性到你的AndroidManifest.xml，你允许所有的http请求:

<application android:usesCleartextTraffic="true">
</application>

但如果你想要更多的配置不同的链接，例如，允许http的一些域，但不允许其他域，你必须提供res/xml/networkSecurityConfig.xml文件。

要在Android 9 Pie中做到这一点，你必须在Manifest应用程序标签中设置networkSecurityConfig，如下所示:

<?xml version="1.0" encoding="utf-8"?>
<manifest ... >
    <application android:networkSecurityConfig="@xml/network_security_config">




    </application>
</manifest>

然后在你的xml文件夹中，你现在必须创建一个名为network_security_config的文件，就像你在清单中命名它的方式一样，从那里，你的文件内容应该像这样，以启用所有不加密的请求:

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config cleartextTrafficPermitted="true">
        <trust-anchors>
            <certificates src="system" />
        </trust-anchors>
    </base-config>
</network-security-config>

然后你就可以继续了。现在你的应用程序将对所有类型的连接发出请求。有关此主题的更多信息，请阅读此处。

You may check if you are sending clearText through HTTP Fix : https://medium.com/@son.rommer/fix-cleartext-traffic-error-in-android-9-pie-2f4e9e2235e6 OR In the Case of Apache HTTP client deprecation (From Google ) : With Android 6.0, we removed support for the Apache HTTP client. Beginning with Android 9, that library is removed from the bootclasspath and is not available to apps by default. To continue using the Apache HTTP client, apps that target Android 9 and above can add the following to their AndroidManifest.xml:

源 https://developer.android.com/about/versions/pie/android-9.0-changes-28

对于在调试中运行的React Native应用程序，将@Xenolion提到的xml块添加到位于<project>/android/app/src/debug/res/xml中的react_native_config.xml中

类似于下面的代码片段:

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="false">localhost</domain>
        <domain includeSubdomains="false">10.0.2.2</domain>
        <domain includeSubdomains="false">10.0.3.2</domain>
    </domain-config>
    <base-config cleartextTrafficPermitted="true">
        <trust-anchors>
            <certificates src="system" />
        </trust-anchors>
    </base-config>
</network-security-config>

这对我很有效，

将此XML文件添加到: andriod / app / src / main / res / xml / network_security_config.xml

network_security_config.xml

xml/network_security_config.xml
<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config cleartextTrafficPermitted="true">
        <trust-anchors>
            <certificates src="system" />
        </trust-anchors>
    </base-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">your_domain1</domain>
    </domain-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">your_domain2</domain>
    </domain-config>
</network-security-config>

然后将此代码添加到AndroidMenifest.xml

<application
    ...
      android:usesCleartextTraffic="true"
      android:networkSecurityConfig="@xml/network_security_config"
    ...
      >
      <!-- for http support-->
      <uses-library android:name="org.apache.http.legacy" android:required="false"/>
      ...
</application>
        

一个简单的方法是设置android:usesCleartextTraffic="true"在你的AndroidManifest.xml

android:usesCleartextTraffic="true"

你的androidmanifest。xml是这样的

<?xml version="1.0" encoding="utf-8"?>
<manifest package="com.dww.drmanar">
   <application
       android:icon="@mipmap/ic_launcher"
       android:label="@string/app_name"
       android:usesCleartextTraffic="true"
       android:theme="@style/AppTheme"
       tools:targetApi="m">
       <activity
            android:name=".activity.SplashActivity"
            android:theme="@style/FullscreenTheme">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
       </activity>
    </application>
</manifest>

我希望这对你有所帮助。