Android Edittext 富文本格式

Question

是否有任何库或开源应用程序演示包含具有所见即所得界面的富文本格式 Edittext 组件。听说 android-richtexteditor 有这样的功能，但是它的源代码已经没有了。

如果有人有以上链接或来源，请与我分享。

Answer 1

这里有两个很棒的库帮助了我。它们都是所见即所得的实现。

Android 实时编辑器： https://github.com/1gravity/Android-RTEditor

RichEditor-Android： https://github.com/wasabeef/richeditor-android

还提供了它们的实现代码。

Answer 2

没有这方面的库，但您可以使用以下类来做到这一点

1.HTML

2.可扩展

3.ForegroundSpan

4.BackgroundSpan

5.AbsoluteSpan

1.http://developer.android.com/reference/android/text/Html.html

使用这个你可以直接嵌入带有 android 的 html 标签，比如粗体，itlic，underlince 等

2.http://developer.android.com/reference/android/text/Spannable.html (SpannableString ,SpannableStringBuilder 等)

编辑

用于编辑文本粗体、斜体等。请参阅以下链接中的一些示例

http://www.androidengineer.com/2010/08/easy-method-for-formatting-android.html

https://blog.stylingandroid.com/introduction-to-spans/

Answer 3

以下是将 EditText 转换为 RichText 的步骤

1) 如下图创建一个RichTextEditor类，本例支持粗体/非粗体，可以根据需要添加更多

import android.app.Activity;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.text.Editable;
import android.text.Selection;
import android.text.Spannable;
import android.text.TextWatcher;
import android.text.style.StyleSpan;
import android.view.View;
import android.widget.AdapterView;
import android.widget.EditText;
import android.widget.ImageButton;

import com.loa.learnandcheck.R;
import com.loa.learnandcheck.util.ResourceHelper;

public class RichTextEditor implements ImageButton.OnClickListener, TextWatcher {
    private boolean textBold;
    private ImageButton buttonBold;
    private EditText editText;
    private Activity parent;
    private int styleStart = 0;

    public RichTextEditor(Activity parent, EditText editText){
        try {
            this.parent = parent;
            this.editText = editText;
            init();
        }catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void init(){
        try {
            buttonBold = (ImageButton)parent.findViewById(R.id.text_control_text_bold);
            if(buttonBold!=null) {
                buttonBold.setOnClickListener(this);
            }
            editText.addTextChangedListener(this);
        }catch (Exception e) {
            e.printStackTrace();
        }
    }

    public Activity getParent() {
        return parent;
    }

    public void setParent(Activity parent) {
        this.parent = parent;
    }

    public void updateBackground(boolean itemSelected, ImageButton button) {
        try {
            if(itemSelected) {
                button.setBackgroundColor(ResourceHelper.getThemeColor(parent,R.color.colorGray, Color.GRAY));
            } else {
                button.setBackgroundColor(ResourceHelper.getThemeColor(parent,R.color.colorWhite, Color.WHITE));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void handleBoldButtonClick() {
        try {
            textBold = !textBold;
            updateBackground(textBold,buttonBold);
            int selectionStart = editText.getSelectionStart();
            int selectionEnd = editText.getSelectionEnd();
            if (selectionStart > selectionEnd){
                int temp = selectionEnd;
                selectionEnd = selectionStart;
                selectionStart = temp;
            }
            if (selectionEnd > selectionStart) {
                Spannable str = editText.getText();
                StyleSpan[] ss = str.getSpans(selectionStart, selectionEnd, StyleSpan.class);
                boolean exists = false;
                for (int i = 0; i < ss.length; i++) {
                    if (ss[i].getStyle() == android.graphics.Typeface.BOLD){
                        str.removeSpan(ss[i]);
                        exists = true;
                    }
                }
                if (!exists){
                    str.setSpan(new StyleSpan(android.graphics.Typeface.BOLD), selectionStart, selectionEnd, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void handleFormat(Editable s, int position, int format) {
        try {
            StyleSpan[] ss = s.getSpans(styleStart, position, StyleSpan.class);
            for (int i = 0; i < ss.length; i++) {
                if (ss[i].getStyle() == format){
                    s.removeSpan(ss[i]);
                }
            }
            s.setSpan(new StyleSpan(format), styleStart, position, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onClick(View view) {
        try {
            switch (view.getId()) {
                case R.id.text_control_text_bold:
                    handleBoldButtonClick();
                    break;
                //more formats to be handled as needed here...
                default:
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public void afterTextChanged(Editable s) {
        int position = Selection.getSelectionStart(editText.getText());
        //handle bold
        if (textBold){
            handleFormat(s, position, android.graphics.Typeface.BOLD);
        }
        //more formats to be handled as needed here...
    }
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
        styleStart = start;
    }
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        //unused
    }

}

2) 创建以下 ResourceHelper 类

public class ResourceHelper {
    /**
     * Get a color value from a theme attribute.
     * @param context used for getting the color.
     * @param attribute theme attribute.
     * @param defaultColor default to use.
     * @return color value
     */
    public static int getThemeColor(Context context, int attribute, int defaultColor) {
        int themeColor = 0;
        String packageName = context.getPackageName();
        try {
            Context packageContext = context.createPackageContext(packageName, 0);
            ApplicationInfo applicationInfo =
                context.getPackageManager().getApplicationInfo(packageName, 0);
            packageContext.setTheme(applicationInfo.theme);
            Resources.Theme theme = packageContext.getTheme();
            TypedArray ta = theme.obtainStyledAttributes(new int[] {attribute});
            themeColor = ta.getColor(0, defaultColor);
            ta.recycle();
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
        return themeColor;
    }
}

3) 使用edittext和控制按钮（ImageButtons）创建布局，如下所示

   <EditText
                android:id="@+id/text_content"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_weight="5"
                android:inputType="textMultiLine"
                android:lines="5"
                android:scrollbars="vertical"
                android:background="@color/colorWhite"

                android:hint="@string/text_content" />


<ImageButton
                            android:id="@+id/text_control_text_bold"
                            android:layout_width="40dp"
                            android:layout_height="40dp"
                            android:background="@color/colorWhite"
                            android:src="@drawable/ic_action_text_bold"/>

4) 在 Activity 中，加载编辑文本并创建 RichTextEditor 实例，如下所示

inputText = (EditText)findViewById(R.id.text_content) ;
new RichTextEditor(this,inputText);