如何在Xamarin Android中的TextView中显示源代码？

Question

我想开发有关编程的教育应用程序，但是我不知道如何在TextView中显示源代码（Java / XML / C＃/ ...）。 我认为这是行不通的，因为语法会混乱。

myTextView.SetText("MY_SOURCE_CODE");

那么，有人对这个问题有想法吗？ 我知道我可以在Android Studio中使用类似CodeView的库，但是我不知道如何在Xamarin.Android中执行此操作

我想创建这样的东西。

Answer 1

您可以参考此CodeView库 ， CodeView的类型是WebView但可以实现相同的功能。 您可以通过从nuget包下载直接使用它：

将视图添加到您的布局：

<br.tiagohm.codeview.CodeView
    android:id="@+id/codeView"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1"
    app:cv_font_size="14"
    app:cv_highlight_line_number="36"
    app:cv_show_line_number="true"
    app:cv_start_line_number="0"
    app:cv_wrap_line="true"
    app:cv_zoom_enable="true">
</br.tiagohm.codeview.CodeView>  

使用时：

public class CodeViewActivity : AppCompatActivity, CodeView.IOnHighlightListener
{

    CodeView mCodeView;
    private ProgressDialog mProgressDialog;
    private int themePos = 0;

    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);

        SetContentView(Resource.Layout.codeView);
        mCodeView = FindViewById<CodeView>(Resource.Id.codeView);

        mCodeView.SetOnHighlightListener(this)
                .SetOnHighlightListener(this)
                .SetTheme(Br.Tiagohm.Theme.ArduinoLight)
                .SetCode(JAVA_CODE)
                .SetLanguage(Language.Auto)
                .SetWrapLine(true)
                .SetFontSize(14)
                .SetZoomEnabled(true)
                .SetShowLineNumber(true)
                .SetStartLineNumber(1)
                .Apply();

        mCodeView.SetTheme(Br.Tiagohm.Theme.All.ElementAt(1)).Apply();
    }

    private void setHighlightTheme(int pos)
    {
        mCodeView.SetTheme(Br.Tiagohm.Theme.All.ElementAt(pos)).Apply();
        Toast.MakeText(this, Br.Tiagohm.Theme.All.ElementAt(pos).Name, ToastLength.Short).Show();
    }

    public void OnFinishCodeHighlight()
    {
        if (mProgressDialog != null)
        {
            mProgressDialog.Dismiss();
        }

        Toast.MakeText(this, "line count: " + mCodeView.LineCount, ToastLength.Short).Show();
    }

    public void OnFontSizeChanged(int sizeInPx)
    {
        Log.Debug("TAG", "font-size: " + sizeInPx + "px");
    }

    public void OnLanguageDetected(Language language, int relevance)
    {
        Toast.MakeText(this, "language: " + language + " relevance: " + relevance, ToastLength.Short).Show();
    }

    public void OnLineClicked(int lineNumber, string content)
    {
        Toast.MakeText(this, "line: " + lineNumber + " html: " + content, ToastLength.Short).Show();
    }

    public void OnStartCodeHighlight()
    {
        mProgressDialog = ProgressDialog.Show(this, null, "Carregando...", true);
    }

    #region Code
    private static String JAVA_CODE = "package com.example.android.bluetoothchat;\n" +

       "\n" +

       "import android.os.Bundle;\n" +

       "import android.support.v4.app.FragmentTransaction;\n" +

       "import android.view.Menu;\n" +

       "import android.view.MenuItem;\n" +

       "import android.widget.ViewAnimator;\n" +

       "\n" +

       "import com.example.android.common.activities.SampleActivityBase;\n" +

       "import com.example.android.common.logger.Log;\n" +

       "import com.example.android.common.logger.LogFragment;\n" +

       "import com.example.android.common.logger.LogWrapper;\n" +

       "import com.example.android.common.logger.MessageOnlyLogFilter;\n" +

       "\n" +

       "/**\n" +

       " * A simple launcher activity containing a summary sample description, sample log and a custom\n" +

       " * {@link android.support.v4.app.Fragment} which can display a view.\n" +

       " * <p>\n" +

       " * For devices with displays with a width of 720dp or greater, the sample log is always visible,\n" +

       " * on other devices it's visibility is controlled by an item on the Action Bar.\n" +

       " */\n" +

       "public class MainActivity extends SampleActivityBase {\n" +

       "\n" +

       "    public static final String TAG = \"MainActivity\";\n" +

       "\n" +

       "    // Whether the Log Fragment is currently shown\n" +

       "    private boolean mLogShown;\n" +

       "\n" +

       "    @Override\n" +

       "    protected void onCreate(Bundle savedInstanceState) {\n" +

       "        super.onCreate(savedInstanceState);\n" +

       "        setContentView(R.layout.activity_main);\n" +

       "\n" +

       "        if (savedInstanceState == null) {\n" +

       "            FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();\n" +

       "            BluetoothChatFragment fragment = new BluetoothChatFragment();\n" +

       "            transaction.replace(R.id.sample_content_fragment, fragment);\n" +

       "            transaction.commit();\n" +

       "        }\n" +

       "    }\n" +

       "\n" +

       "    @Override\n" +

       "    public boolean onCreateOptionsMenu(Menu menu) {\n" +

       "        getMenuInflater().inflate(R.menu.main, menu);\n" +

       "        return true;\n" +

       "    }\n" +

       "\n" +

       "    @Override\n" +

       "    public boolean onPrepareOptionsMenu(Menu menu) {\n" +

       "        MenuItem logToggle = menu.findItem(R.id.menu_toggle_log);\n" +

       "        logToggle.setVisible(findViewById(R.id.sample_output) instanceof ViewAnimator);\n" +

       "        logToggle.setTitle(mLogShown ? R.string.sample_hide_log : R.string.sample_show_log);\n" +

       "\n" +

       "        return super.onPrepareOptionsMenu(menu);\n" +

       "    }\n" +

       "\n" +

       "    @Override\n" +

       "    public boolean onPrepareOptionsMenu(Menu menu) {\n" +

       "        MenuItem logToggle = menu.findItem(R.id.menu_toggle_log);\n" +

       "        logToggle.setVisible(findViewById(R.id.sample_output) instanceof ViewAnimator);\n" +

       "        logToggle.setTitle(mLogShown ? R.string.sample_hide_log : R.string.sample_show_log);\n" +

       "\n" +

       "        return super.onPrepareOptionsMenu(menu);\n" +

       "    }\n" +

       "\n" +

       "    @Override\n" +

       "    public boolean onPrepareOptionsMenu(Menu menu) {\n" +

       "        MenuItem logToggle = menu.findItem(R.id.menu_toggle_log);\n" +

       "        logToggle.setVisible(findViewById(R.id.sample_output) instanceof ViewAnimator);\n" +

       "        logToggle.setTitle(mLogShown ? R.string.sample_hide_log : R.string.sample_show_log);\n" +

       "\n" +

       "        return super.onPrepareOptionsMenu(menu);\n" +

       "    }\n" +

       "\n" +

       "    @Override\n" +

       "    public boolean onOptionsItemSelected(MenuItem item) {\n" +

       "        switch(item.getItemId()) {\n" +

       "            case R.id.menu_toggle_log:\n" +

       "                mLogShown = !mLogShown;\n" +

       "                ViewAnimator output = (ViewAnimator) findViewById(R.id.sample_output);\n" +

       "                if (mLogShown) {\n" +

       "                    output.setDisplayedChild(1);\n" +

       "                } else {\n" +

       "                    output.setDisplayedChild(0);\n" +

       "                }\n" +

       "                supportInvalidateOptionsMenu();\n" +

       "                return true;\n" +

       "        }\n" +

       "        return super.onOptionsItemSelected(item);\n" +

       "    }\n" +

       "\n" +

       "    /** Create a chain of targets that will receive log data */\n" +

       "    @Override\n" +

       "    public void initializeLogging() {\n" +

       "        // Wraps Android's native log framework.\n" +

       "        LogWrapper logWrapper = new LogWrapper();\n" +

       "        // Using Log, front-end to the logging chain, emulates android.util.log method signatures.\n" +

       "        Log.setLogNode(logWrapper);\n" +

       "\n" +

       "        // Filter strips out everything except the message text.\n" +

       "        MessageOnlyLogFilter msgFilter = new MessageOnlyLogFilter();\n" +

       "        logWrapper.setNext(msgFilter);\n" +

       "\n" +

       "        // On screen logging via a fragment with a TextView.\n" +

       "        LogFragment logFragment = (LogFragment) getSupportFragmentManager()\n" +

       "                .findFragmentById(R.id.log_fragment);\n" +

       "        msgFilter.setNext(logFragment.getLogView());\n" +

       "\n" +

       "        Log.i(TAG, \"Ready\");\n" +

       "    }\n" +

       "}";
    #endregion
}

效果 。