错误: 程序包android.support.v4.content不存在

android.support.v4.content.FileProvider     替换   androidx.core.content.FileProvider
android.support.v4.content.ContextCompat    替换   androidx.core.content.ContextCompat
android.support.v4.app.ActivityCompat       替换   androidx.core.app.ActivityCompat

import androidx.core.content.FileProvider;

import androidx.core.content.ContextCompat;
import androidx.core.app.ActivityCompat;

 

 

 

 

 

错误：

You need to use a Theme.AppCompat theme (or descendant) with this activity

 

解决办法：

1、把 AppCompatActivity 换成 Activity

2、注释代码段