Question

我需要你的帮助，如果你很友好，我需要解决我在Android应用中遇到的问题：

我设法在MainActivity中捕获图片并将其显示在一个单独的活动中 - PictureActivity。我的代码如下：

在 MainActivity 中，我有

private static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 100;

/**
 * This is called in tap on a graphic element in my MainActivity layout
 */
public void launchCamera(View v) {
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE) {
            Bitmap imageData = null;

            if (resultCode == RESULT_OK) {
                imageData = (Bitmap) data.getExtras().get("data");

                Intent i = new Intent(this, PictureActivity.class);
                i.putExtra("captured_picture", imageData);
                startActivity(i);
            } else if (resultCode == RESULT_CANCELED) {
                // User cancelled the image capture
            } else {
                Toast.makeText(getApplicationContext(), R.string.picture_capture_error, Toast.LENGTH_SHORT).show();
            }
        }
    }

我的 PictureActivity 如下所示：

public class PictureActivity extends ActionBarActivity {

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

        Bitmap bitmap  = getIntent().getExtras().getParcelable("captured_picture");

        ImageView view = (ImageView) findViewById(R.id.preview_photo);
        view.setImageBitmap(bitmap);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.image_menu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();


        return super.onOptionsItemSelected(item);
    }
}

我的 PictureActivity布局看起来像这样

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/preview_photo"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>

这是迄今为止最终结果的表现：

PictureActivity screen preview

长话短说，这些是我想要做的事情下一步：

如果用户点击主操作栏中的中间按钮
如果用户点击左侧第一个按钮

接下来，将图像保存在某处（在共享首选项或会话中可能？），然后将其上传到远程服务器。我说“将图像保存在某个地方”因为用户可以选择拍摄第二张照片（最多两张）并执行相同的动作，如上所述（通过点击第一个按钮）从右边开始，在主动作栏中。）

到目前为止我无法弄清楚：

我怎么知道当前图像是什么（我在屏幕上看到的）
如何设置它的名称以及它应保存到的位置，直到我将其上传到远程服务器
当我点击其中一个按钮（裁剪或旋转）时，我该如何操纵它

很抱歉这篇长篇文章，并提前感谢您的帮助！

Answer 1

回答你的3个问题：

您看到的当前图像位于设备RAM中。它是保存数据的位图对象。
您必须将位图保存到设备存储
您必须先转换位图，然后再将其保存到存储

以下是一些可能对您有用的代码：

public static void saveBitmapToFile(Bitmap bitmap, String filename){
        FileOutputStream out = null;
        try {
            out = new FileOutputStream(filename);
            bitmap.compress(Bitmap.CompressFormat.PNG, 100, out); // bmp is your Bitmap instance
            // PNG is a lossless format, the compression factor (100) is ignored 
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (out != null) {
                    out.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

public static Bitmap cropAndRotateBitmap(Bitmap bitmap, Rect cropRect, int rotateByDegrees) {
        Log.v(TAG, "cropAndRotateBitmap()");
        Log.v(TAG, "bitmap: " + bitmap);
        //Log.v(TAG, "orientation: " + orientation);
        Log.v(TAG, "degrees: " + rotateByDegrees);
        Log.v(TAG, "cropRect: " + cropRect);
        int cropRectWidth = cropRect.right - cropRect.left;
        int cropRectHeight = cropRect.bottom - cropRect.top;

        System.gc();

        Bitmap result;
        Matrix m = new Matrix();
        Canvas canvas = new Canvas();
        if (rotateByDegrees == 0) {
            result = Bitmap.createBitmap(cropRectWidth, cropRectHeight, Bitmap.Config.ARGB_8888);
            canvas = new Canvas(result);
            m.postTranslate(-cropRect.left, -cropRect.top);

        } else if (rotateByDegrees == 90) {
            Log.v(TAG, "rotate 90, cropRect: " + cropRect);
            result = Bitmap.createBitmap(cropRectHeight, cropRectWidth, Bitmap.Config.ARGB_8888);
            canvas = new Canvas(result);
            m.postTranslate(-cropRect.left, -cropRect.height() - cropRect.top);
            m.postRotate(90);

        } else if (rotateByDegrees == 180) {
            Log.v(TAG, "rotate 180");
            result = Bitmap.createBitmap(cropRectWidth, cropRectHeight, Bitmap.Config.ARGB_8888);
            canvas = new Canvas(result);
            m.postTranslate(-cropRect.left - cropRect.width(), -cropRect.height() - cropRect.top);
            m.postRotate(180);

        } else { // 270
            Log.v(TAG, "rotate 270");
            result = Bitmap.createBitmap(cropRectHeight, cropRectWidth, Bitmap.Config.ARGB_8888);
            canvas = new Canvas(result);
            m.postTranslate(-cropRect.width() - cropRect.left, -cropRect.top);
            m.postRotate(270);

        }
        Paint whitePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        whitePaint.setStyle(Paint.Style.FILL);
        whitePaint.setColor(Color.WHITE);

        canvas.drawBitmap(bitmap, m, whitePaint);
        // canvas.restore();
        return result;
    }

    public static Bitmap rotateBitmap(Bitmap bitmap, int rotateByDegrees) {

        Log.v(TAG, "rotateBitmap()");
        Log.v(TAG, "degrees: " + rotateByDegrees);

        System.gc();

        Bitmap result;
        Canvas canvas = new Canvas();
        if (rotateByDegrees == 0) {
            result = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
            canvas = new Canvas(result);
            canvas.save();
        } else if (rotateByDegrees == 90) {
            result = Bitmap.createBitmap(bitmap.getHeight(), bitmap.getWidth(), Bitmap.Config.ARGB_8888);
            canvas = new Canvas(result);
            canvas.save();
            canvas.rotate(90);
            canvas.translate(0, -1 * bitmap.getHeight());
        } else if (rotateByDegrees == 180) {
            result = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
            canvas = new Canvas(result);
            canvas.save();
            canvas.rotate(180);
            canvas.translate(-1 * bitmap.getWidth(), -1 * bitmap.getHeight());
        } else { // 270
            result = Bitmap.createBitmap(bitmap.getHeight(), bitmap.getWidth(), Bitmap.Config.ARGB_8888);
            canvas = new Canvas(result);
            canvas.save();
            canvas.rotate(270);
            canvas.translate(-1 * bitmap.getWidth(), 0);
        }

        canvas.drawBitmap(bitmap, new Matrix(), null);
        canvas.restore();
        return result;
    }

捕获后的图片处理

1 个答案: