Android ClickableSpan 不改变样式 onclick

Question

我有一个 TextView，其中所有单词都可以单独点击。我想从每一个没有风格的词开始。单击一个词后，该词应变为并保持下划线。我能够清除默认下划线，但点击后没有任何反应。 (我正在捕获甚至处理点击，但我无法更改 Span 样式)。

相关代码如下。预先感谢您的帮助。

自定义 ClickableSpan:

class WordSpan extends ClickableSpan {
  private TextPaint textpaint;
  public boolean clicked = false;

  @Override
  public void updateDrawState(TextPaint ds) {
    textpaint = ds;
    ds.setUnderlineText(false);

    if (clicked)
      ds.setUnderlineText(true);
  }

  @Override
  public void onClick(View v) {}

  public void setClicked(boolean c) {
    clicked = c;
    updateDrawState(textpaint);
  }
}

我从 onCreate() 解析一个 txt 文件并将每个单词添加到 TextView。在这个解析循环中，我有以下代码:

  SpannableString ss = new SpannableString(word.toString());

  WordSpan clickableSpan = new WordSpan() {
    @Override
    public void onClick(View view) {
    setClicked(true);
    view.invalidate();
    }};

  ss.setSpan(clickableSpan, 0, word.toString().length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);

  tvText.append(ss);
  tvText.append(" ");
}

tvText.setMovementMethod(LinkMovementMethod.getInstance());

Answer 1

要使单个单词可点击，您必须向 spannable 字符串添加多个可点击的 span。例如，要在单个 Textview 中单独点击“foo”和“bar”，您必须添加两个可点击的 span，一个用于“foo”，另一个用于“bar”，并将它们添加到 spannable 字符串中。

在示例中，为了简单起见，我使用空格拆分了字符串，而且您还必须为单击跨度编写逻辑。

删除下划线的可点击范围。此外，您可以在单击时配置背景和文本颜色。如果您不打算使用它，可以将其删除。

import android.text.TextPaint;
import android.text.style.ClickableSpan;

public abstract class TouchableSpan  extends ClickableSpan {
    private boolean mIsPressed;
    private int mPressedBackgroundColor;
    private int mNormalTextColor;
    private int mPressedTextColor;
    private int mBackgroundColor;

    public TouchableSpan(int normalTextColor,int backgroundColor, int pressedTextColor, int pressedBackgroundColor) {
        mBackgroundColor = backgroundColor;
        mNormalTextColor = normalTextColor;
        mPressedTextColor = pressedTextColor;
        mPressedBackgroundColor = pressedBackgroundColor;
    }

    public void setPressed(boolean isSelected) {
        mIsPressed = isSelected;
    }

    @Override
    public void updateDrawState(TextPaint ds) {
        super.updateDrawState(ds);
        ds.setColor(mIsPressed ? mPressedTextColor : mNormalTextColor);
        ds.bgColor = mIsPressed ? mPressedBackgroundColor : mBackgroundColor;
        ds.setUnderlineText(!mIsPressed);
    }
}

创建一个 LinkMovementMethod 来处理您的 Span。如果您删除颜色规定，您也可以更改它

import android.text.Layout;
import android.text.Selection;
import android.text.Spannable;
import android.text.method.LinkMovementMethod;
import android.text.method.MovementMethod;
import android.view.MotionEvent;
import android.widget.TextView;

public class LinkTouchMovementMethod extends LinkMovementMethod {

    private TouchableSpan mPressedSpan;

    @Override
    public boolean onTouchEvent(TextView textView, Spannable spannable, MotionEvent event) {
        if (event.getAction() == MotionEvent.ACTION_DOWN) {
            mPressedSpan = getPressedSpan(textView, spannable, event);
            if (mPressedSpan != null) {
                mPressedSpan.setPressed(true);
                Selection.setSelection(spannable, spannable.getSpanStart(mPressedSpan),
                        spannable.getSpanEnd(mPressedSpan));
            }
        } else if (event.getAction() == MotionEvent.ACTION_MOVE) {
            TouchableSpan touchedSpan = getPressedSpan(textView, spannable, event);
            if (mPressedSpan != null && touchedSpan != mPressedSpan) {
                mPressedSpan.setPressed(false);
                mPressedSpan = null;
                Selection.removeSelection(spannable);
            }
        } else {
            if (mPressedSpan != null) {
                mPressedSpan.setPressed(false);
                super.onTouchEvent(textView, spannable, event);
            }
            mPressedSpan = null;
            Selection.removeSelection(spannable);
        }
        return true;
    }

    private TouchableSpan getPressedSpan(TextView textView, Spannable spannable, MotionEvent event) {

        int x = (int) event.getX();
        int y = (int) event.getY();

        x -= textView.getTotalPaddingLeft();
        y -= textView.getTotalPaddingTop();

        x += textView.getScrollX();
        y += textView.getScrollY();

        Layout layout = textView.getLayout();
        int line = layout.getLineForVertical(y);
        int off = layout.getOffsetForHorizontal(line, x);

        TouchableSpan[] link = spannable.getSpans(off, off, TouchableSpan.class);
        TouchableSpan touchedSpan = null;
        if (link.length > 0) {
            touchedSpan = link[0];
        }
        return touchedSpan;
    }

}

那么您可以通过以下方式使用它:

TextView textView = (TextView)findViewById(R.id.hello_world);
String fooBar = "asdfasdfasdfasf asdfasfasfasd";
String[] clickSpans = fooBar.split(" ");
int clickSpanLength = clickSpans.length;
SpannableStringBuilder spannableStringBuilder = new SpannableStringBuilder();
int totalLength = 0;
int normalColor = getResources().getColor(android.R.color.black);
int clickColor = getResources().getColor(android.R.color.holo_blue_bright);
String separator = " , ";
int separatorLength = separator.length();
for (int i = 0; i < clickSpanLength; i++) {
    int currentWordLength = clickSpans[i].length();
    spannableStringBuilder.append(clickSpans[i]);
    if (i < clickSpanLength - 1) {
        spannableStringBuilder.append(" , ");
    }

    spannableStringBuilder.setSpan(new TouchableSpan(normalColor, Color.TRANSPARENT, clickColor, Color.TRANSPARENT) {
        @Override
        public void onClick(View widget) {

        }
    }, totalLength, totalLength + currentWordLength, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
    totalLength = totalLength + currentWordLength + separatorLength;
}

textView.setText(spannableStringBuilder);
textView.setMovementMethod(new LinkTouchMovementMethod());