'startActivityForResult(android.content.Intent, int)' 已弃用 我能做什么？

Question

'startActivityForResult(android.content.Intent, int)' 已弃用，我该怎么办？这是我的二维码扫描仪 Android 应用程序 (Java) 的代码：

package com.example.wfr;

import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {
    private static final int REQUEST_CODE = 0;

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


        //Button click event to open QR scanner
        findViewById(R.id.camera_button).setOnClickListener(v -> {
            Intent intent = new Intent(MainActivity.this, QRCodeScanner.class);
            intent.putExtra("SCAN_FORMATS", "QR_CODE");
            startActivityForResult(intent, REQUEST_CODE);
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == REQUEST_CODE && resultCode == RESULT_OK) {
            if (data != null) {
                String scannedText = data.getStringExtra("com.journeyapps.barcodescanner.CaptureActivity.SCAN_RESULT");
                TextView scannedTextView = findViewById(R.id.scanned_text);
                scannedTextView.setText(scannedText);
            }
        }
    }
}

Answer 1

基本培训可在https://developer.android.com/training/basics/intents/result上获得

以下是如何将现有代码转换为新代码的示例：

老办法：

public void openSomeActivityForResult() {
    Intent intent = new Intent(this, SomeActivity.class);
    startActivityForResult(intent, 123);
}

@Override
protected void onActivityResult (int requestCode, int resultCode, Intent data) {
    if (resultCode == Activity.RESULT_OK && requestCode == 123) {
        doSomeOperations();
    }
}

新方法（Java）：

public void openSomeActivityForResult() {
    Intent intent = new Intent(this, SomeActivity.class);
    someActivityResultLauncher.launch(intent);
}

// You can do the assignment inside onAttach or onCreate, i.e, before the activity is displayed
ActivityResultLauncher<Intent> someActivityResultLauncher = registerForActivityResult(
        new ActivityResultContracts.StartActivityForResult(),
        new ActivityResultCallback<ActivityResult>() {
            @Override
            public void onActivityResult(ActivityResult result) {
                if (result.getResultCode() == Activity.RESULT_OK) {
                    // There are no request codes
                    Intent data = result.getData();
                    doSomeOperations();
                }
            }
        });

这是你的代码

public class MainActivity extends AppCompatActivity {

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


        //Button click event to open QR scanner
        findViewById(R.id.camera_button).setOnClickListener(v -> {
            Intent intent = new Intent(MainActivity.this, QRCodeScanner.class);
            intent.putExtra("SCAN_FORMATS", "QR_CODE");
             someActivityResultLauncher.launch(intent);
        });
    }

// You can do the assignment inside onAttach or onCreate, i.e, before the activity is displayed
ActivityResultLauncher<Intent> someActivityResultLauncher = registerForActivityResult(
        new ActivityResultContracts.StartActivityForResult(),
        new ActivityResultCallback<ActivityResult>() {
            @Override
            public void onActivityResult(ActivityResult result) {
                if (result.getResultCode() == Activity.RESULT_OK) {
                    // There are no request codes
                    Intent data = result.getData();
                    if (data != null) {
                String scannedText = data.getStringExtra("com.journeyapps.barcodescanner.CaptureActivity.SCAN_RESULT");
                TextView scannedTextView = findViewById(R.id.scanned_text);
                scannedTextView.setText(scannedText);
            }
                }
            }
        });
}