java - 在现有项目上集成 git 项目 startActivityForResult 和 onActivityResult android

Question

我实现了这个git在我当前的项目中，没有克隆

implementation 'com.github.adityaarora1:LiveEdgeDetection:master-SNAPSHOT'

但我无法在我的方法上调用它。文档说

1. 从您的 Activity 中启动 startActivityForResult

   startActivityForResult(new Intent(this, ScanActivity.class), REQUEST_CODE);
   

2. 在 onActivityResult 上获取裁剪图像的文件路径

   String filePath =  data.getExtras().getString(ScanConstants.SCANNED_RESULT);
   Bitmap baseBitmap = ScanUtils.decodeBitmapFromFile(filePath, ScanConstants.IMAGE_NAME);
   

所以我尝试从新类中像这样调用 onClick 按钮

   scan.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent myIntent = new Intent(MainActivity.this,
                        ScanActivity.class);
                startActivity(myIntent);
            }

并将其余部分放入我的 onActivityResult

 protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    String filePath = data.getExtras().getString(ScanConstants.SCANNED_RESULT);
    Bitmap baseBitmap = ScanUtils.decodeBitmapFromFile(filePath, ScanConstants.IMAGE_NAME);
}

编辑:这是作者在 git 上使用的 MainActivity 我尝试使用它，但收到此错误:

scannedImageView = findViewById(com.adityaarora.liveedgedetection.R.id.scanned_image);

MainActivity(已导入)

private static final int REQUEST_CODE = 101;
private ImageView scannedImageView;
Button scan;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_scan);
    scannedImageView = findViewById(com.adityaarora.liveedgedetection.R.id.scanned_image);
    startScan();

    scan = findViewById(R.id.open_scan);
        scan.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent myIntent = new Intent(ScanActivity2.this,
                    ScanActivity.class);
            startActivityForResult(myIntent ,111);
        }
    });
}

private void startScan() {
    Intent intent = new Intent(this, ScanActivity.class);
    startActivityForResult(intent, REQUEST_CODE);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == REQUEST_CODE) {
        if(resultCode == Activity.RESULT_OK) {
            if(null != data && null != data.getExtras()) {
                String filePath = data.getExtras().getString(ScanConstants.SCANNED_RESULT);
                Bitmap baseBitmap = ScanUtils.decodeBitmapFromFile(filePath, ScanConstants.IMAGE_NAME);
                scannedImageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
                scannedImageView.setImageBitmap(baseBitmap);
            }
        } else if(resultCode == Activity.RESULT_CANCELED) {
            finish();
        }
    }
}

更新:

经过一番研究，我发现导入的项目仅读取文件且无法更改(ScanActivity.java)，并且我当前的项目已更新 sdk 28，这与导入的项目不同，因此 ScanActivity 中存在一些错误，即为什么按钮(技术上)不起作用

Answer 1

您应该使用 startActivityForResult 而不是如下所示的 startActivity。

scan.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
         Intent myIntent = new Intent(MainActivity.this,
                        ScanActivity.class);
         startActivityForResult(myIntent ,111);
    }
});

并修改您的onActivityResult，例如

protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if(resultCode == Activity.RESULT_OK && requestCode == 111){
         String filePath = data.getExtras().getString(ScanConstants.SCANNED_RESULT);
         Bitmap baseBitmap = ScanUtils.decodeBitmapFromFile(filePath, ScanConstants.IMAGE_NAME);
         Log.d("YourTAG","File Path "+filePath);
         // here you can set bitmap to your image view 
         yourImageView.setImageBitmap(baseBitmap);
    }
}

更新

您的主要 Activity 应该是这样的

private static final int REQUEST_CODE = 111;
private ImageView scannedImageView;
Button scan;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_scan);
    scannedImageView = findViewById(R.id.scanned_image); // this  ImageView should be in your activity_scan.xml file with same id(scanned_image)
    startScan();

    scan = findViewById(R.id.open_scan);
    scan.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
           startScan();
        }
    });
}

private void startScan() {
    Intent intent = new Intent(ScanActivity2.this, ScanActivity.class);
    startActivityForResult(intent, REQUEST_CODE);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == REQUEST_CODE) {
        if(resultCode == Activity.RESULT_OK) {
            if(null != data && null != data.getExtras()) {
                String filePath = data.getExtras().getString(ScanConstants.SCANNED_RESULT);
                Bitmap baseBitmap = ScanUtils.decodeBitmapFromFile(filePath, ScanConstants.IMAGE_NAME);
                scannedImageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
                scannedImageView.setImageBitmap(baseBitmap);
            }
        } else if(resultCode == Activity.RESULT_CANCELED) {
            finish();
        }
    }
}

演示项目

我已在 Github 上上传了一个演示项目，该项目集成了 LiveEdgeDetection 库并按预期工作。检查一下go here