Question

我的应用程序是某种“迷你颜料”，我想将当前视图保存到设备内存中...我也想做相反的过程（从设备内存加载图像并设置它作为我的当前观点）

MiniPaint

是的，我想这是一个火烈鸟，我是一个艺术家！

Answer 1

我自己没有尝试过，但this answer显示通过获取根视图并保存其绘图缓存来以编程方式截取屏幕截图。这可能是您保存绘画所需的全部内容。

编辑：固定链接

Answer 2

首先，我假设您正在通过覆盖View对象上的onDraw（）方法来执行此绘图，该对象传入Canvas对象，然后您可以对其执行一些绘制操作。

这是解决此问题的一种非常基本的方法。可能需要考虑许多其他注意事项，例如您读取和写入的文件格式，以及I / O代码中的一些额外错误处理。但这应该让你前进。

要保存当前的绘图，请将View的drawingCache写出到Picture对象，然后使用Picture的writeToStream方法。

要加载预先存在的图片，您可以使用Picture.readFromStream方法，然后在onDraw调用中，将加载的图片绘制到Canvas。

To Wit：

/**
 * Saves the current drawing cache of this View object to external storage.
 * @param filename a file to be created in the device's Picture directory on the SD card
 */
public void SaveImage(String filename) {
    // Grab a bitmap of what you've drawn to this View object so far
    Bitmap b = this.getDrawingCache();
    // It's easy to save a Picture object to disk, so we copy the contents
    // of the Bitmap into a Picture
    Picture pictureToSave = new Picture();
    // To copy the Bitmap into the Picture, we have to use a Canvas
    Canvas c = pictureToSave.beginRecording(b.getWidth(), b.getHeight());
    c.drawBitmap(b, 0, 0, new Paint());
    pictureToSave.endRecording();

    // Create a File object where we are going to write the Picture to
    File file = new File(this.getContext().getExternalFilesDir(Environment.DIRECTORY_PICTURES), filename);
    try {
        file.createNewFile();
    }
    catch (IOException ioe) {
        ioe.printStackTrace();
    }
    // Write the contents of the Picture object to disk
    try {
        OutputStream os = new FileOutputStream(file);
        pictureToSave.writeToStream(os);
        os.close();
    }
    catch (FileNotFoundException fnfe) {
        fnfe.printStackTrace();
    }
}

/**
 * Returns a Picture object loaded from external storage
 * @param filename the name of the file in the Pictures directory on the SD card
 * @return null if the file is not found, or a Picture object.
 */
public Picture LoadImage(String filename) {
    // Load a File object where we are going to read the Picture from
    File file = new File(this.getContext().getExternalFilesDir(Environment.DIRECTORY_PICTURES), filename);
    Picture pictureToLoad = null;
    try {
        InputStream is = new FileInputStream(file);
        pictureToLoad = Picture.createFromStream(is);
        is.close();
    }
    catch (FileNotFoundException fnfe) {
        fnfe.printStackTrace();
    }
    // Return the picture we just loaded. Draw the picture to canvas using the
    // Canvas.draw(Picture) method in your View.onDraw(Canvas) method
    return pictureToLoad;
}

我读到的有用链接可以解决这个问题：

从当前视图创建图像。如何？

2 个答案:

To Wit：