安卓如何复制图片到剪贴板/剪贴数据（clipdata）？

Question

在网页或其他地方长按图片可以给我把图片复制到设备剪贴板的机会。请看下面：

现在我想把这个功能实现到我的应用程序中。目前为止，我已经做了以下工作：

代码

Bitmap bitmap = getBitmap();
        File file = storeImage(bitmap, name);

        //Share
        Intent shareIntent = new Intent(Intent.ACTION_SEND);
        shareIntent.setType("image/*");
        Uri uri = Uri.fromFile(file);
        shareIntent.putExtra(Intent.EXTRA_STREAM, uri);

        //Add Copy to Clipboard to choosers
        Intent clipboard = new Intent(this, CopyToClipboardImageActivity.class);
        clipboard.setData(uri);

        Intent chooserIntent = Intent.createChooser(shareIntent, getString(R.string.shareScreenshot));
        chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Intent[]{clipboard});
        startActivity(chooserIntent);

CopyToClipboardImageActivity

  public class CopyToClipboardImageActivity extends Activity {

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            Uri uri = getIntent().getData();
            if (uri != null) {
                copyImageToClipboard(uri);
                Toast.makeText(this, getString(R.string.hinweisInZwischenablageKopiert), Toast.LENGTH_SHORT).show();
            }

            // Finish right away. We don't want to actually display a UI.
            finish();
        }

        private void copyImageToClipboard(Uri uri) {
            ClipboardManager mClipboard = (ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
            ContentValues values = new ContentValues(2);
            values.put(MediaStore.Images.Media.MIME_TYPE, "Image/jpg");
            values.put(MediaStore.Images.Media.DATA,  "file://"+uri.getPath());

            ContentResolver theContent = getContentResolver();
            Uri imageUri = theContent.insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
            ClipData theClip = ClipData.newUri(getContentResolver(), "Image", imageUri);
            mClipboard.setPrimaryClip(theClip);
        }
    }

但是目前还无法实现。要么只会将奇怪的路径复制到剪贴板中（见上图^^），要么会出现以下NullpointerException：

尝试在空对象引用上调用虚拟方法“java.lang.String android.net.Uri.getScheme()”

这个错误发生在这一行： ClipData theClip = ClipData.newUri(getContentResolver(), "Image", imageUri);

- XxGoliathusxX

Answer 1

不要使用MediaStore数据库中的值。将图像保存到您具有使用权限的sdcard上。如何获取权限（清单）：

    <?xml version="1.0" encoding="utf-8"?>
    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
        package="com.example.html2pdf"
        android:versionCode="1"
        android:versionName="1.0" >

        <uses-sdk
            android:minSdkVersion="16"
            android:targetSdkVersion="19" />
        <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"         />    
        <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"        />
                <activity
            android:name=".CopyToClipboardImageActivity"
            android:label="@string/app_name" >
                <intent-filter>
        <action android:name="android.intent.action.SEND" />
        <category android:name="android.intent.category.DEFAULT" />
        <data android:mimeType="image/*" />
    </intent-filter>
    <intent-filter>
        <action android:name="android.intent.action.SEND" />
        <category android:name="android.intent.category.DEFAULT" />
        <data android:mimeType="text/plain" />
    </intent-filter>
    <intent-filter>
        <action android:name="android.intent.action.SEND_MULTIPLE" />
        <category android:name="android.intent.category.DEFAULT" />
        <data android:mimeType="image/*" />
    </intent-filter>
        </activity>
some code:

        final File sdcard = Environment.getExternalStorageDirectory();
        String absoluteFilePath = sdcard.getAbsolutePath() + "/tmp.jpg";
        File aFile = saveBitmap(bitmap , sdcard.getAbsolutePath(), "tmp", Bitmap.CompressFormat.JPEG);


            Intent shareIntent = new Intent(Intent.ACTION_SEND);
            shareIntent.setType("image/*");
            Uri uri = Uri.fromFile(new File(absoluteFilePath));
            shareIntent.putExtra(Intent.EXTRA_STREAM, uri);
            startActivity(shareIntent );

    /**
     * Saves the bitmap by given directory, filename, and format; if the directory is given null,
     * then saves it under the cache directory.
     */
    int DEFAULT_COMPRESS_QUALITY = 100;
    public File saveBitmap(
            Bitmap bitmap, String directory, String filename, CompressFormat format) 
    {
        if (directory == null) 
        {
            directory = this.getCacheDir().getAbsolutePath();
        } else 
        {
            // Check if the given directory exists or try to create it.
            File file = new File(directory);
            if (!file.isDirectory() && !file.mkdirs()) 
            {
                return null;
            }
        }

        File file = null;
        OutputStream os = null;
        try {
            filename = (format == CompressFormat.PNG) ? filename + ".png" : filename + ".jpg";
            file = new File(directory, filename);
            os = new FileOutputStream(file);
            bitmap.compress(format, DEFAULT_COMPRESS_QUALITY, os);
        } catch (FileNotFoundException e) 
        {
            e.printStackTrace();
        } finally {
            try {
                os.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return file;
    }
}

这个剪贴板功能无法用于粘贴图片，详见： 在Android中使用剪贴板管理器复制粘贴图片。

- Jon Goodwin