Java 如何从android中的另一个应用程序以编程方式安装apk

我想以编程方式安装我的应用程序的新版本。对于targetSdkVersion=23，应用程序工作正常，以下是我的代码：

public class MainActivity extends AppCompatActivity {
    private int PERMISSION_REQUEST_STORAGE = 0;
    private DownloadController downloadController;

    Button btn_download;

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

        btn_download = findViewById(R.id.buttonDownload);

        btn_download.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                checkStoragePermission();
            }
        });
    }

    public void checkStoragePermission() {
        if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {

            String url= getApplicationContext().getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS).toString() + "/example.apk";
            Intent intent = new Intent(Intent.ACTION_VIEW);
            intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
            intent.setDataAndType(Uri.parse("file://" + url), "application/vnd.android.package-archive");
            String selfPackageName = getApplicationContext().getPackageName();
            ComponentName componentName = intent.resolveActivity(getApplicationContext().getPackageManager());
            String otherPackageName = (componentName != null ? componentName.getPackageName() : "");

            if (MainActivity.this == null || !selfPackageName.equals(otherPackageName)) {
                intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            }
           startActivity(intent);

        } else {
            requestStoragePermission();
        }
    }

    public void requestStoragePermission() {
        ActivityCompat.requestPermissions(
                MainActivity.this,
                new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                PERMISSION_REQUEST_STORAGE);
    }
}

但是对于targetSdkVersion=29，我听说我必须使用FileProvider。我使用了instructure，但不幸的是它没有打开我的apk进行安装。这是我的res=>xml=>file\u provider\u paths.xml

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <external-path
        name="external"
        path="." />
    <external-files-path
        name="external_files"
        path="." />
    <files-path
        name="files"
        path="." />
</paths>

我得到这个错误

2019-12-17 00:46:38.035 32020-32020/com.example.myapp E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.mysms, PID: 32020
    android.os.FileUriExposedException: file:///storage/emulated/0/Android/data/com.example.myapp/files/Download/example.apk exposed beyond app through Intent.getData()
        at android.os.StrictMode.onFileUriExposed(StrictMode.java:1799)
        at android.net.Uri.checkFileUriExposed(Uri.java:2346)
        at android.content.Intent.prepareToLeaveProcess(Intent.java:8933)
        at android.content.Intent.prepareToLeaveProcess(Intent.java:8894)
        at android.app.Instrumentation.execStartActivity(Instrumentation.java:1517)
        at android.app.Activity.startActivityForResult(Activity.java:4224)
        at androidx.fragment.app.FragmentActivity.startActivityForResult(FragmentActivity.java:767)
        at android.app.Activity.startActivityForResult(Activity.java:4183)
        at androidx.fragment.app.FragmentActivity.startActivityForResult(FragmentActivity.java:754)
        at android.app.Activity.startActivity(Activity.java:4507)
        at android.app.Activity.startActivity(Activity.java:4475)
        at com.example.mysms.MainActivity.checkStoragePermission(MainActivity.java:107)
        at com.example.mysms.MainActivity$3.onClick(MainActivity.java:76)
        at android.view.View.performClick(View.java:5610)
        at android.view.View$PerformClick.run(View.java:22265)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6077)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

---

问题似乎是您为意图数据设置了错误的uri：

install.setData(Uri.fromFile(file));

您需要设置使用FileProvider创建的uri：

Uri uri = FileProvider.getUriForFile(getApplicationContext(), "com.example.myapp", file);
install.setData(uri);

在您找到的说明中也有相同的操作：

val contentUri = FileProvider.getUriForFile(
    context,
    BuildConfig.APPLICATION_ID + PROVIDER_PATH,
    File(destination)
)
val install = Intent(Intent.ACTION_VIEW)
install.data = contentUri

Uri uri = FileProvider.getUriForFile(getApplicationContext(), "com.example.myapp", file);
install.setData(uri);

val contentUri = FileProvider.getUriForFile(
    context,
    BuildConfig.APPLICATION_ID + PROVIDER_PATH,
    File(destination)
)
val install = Intent(Intent.ACTION_VIEW)
install.data = contentUri