问题描述
我正在尝试更改TextView
中下划线指示器的颜色.
I am trying to change the color of the underline indicator in a TextView
.
我知道我可以在这样的文本下划线
I know I can underline text like this
Spanned htmlString = Html.fromHtml("<u> <font color=\"#FF0000\"> some text </font> </u>")
someTextView.setText(htmlString);
像这样
SpannableString content = new SpannableString(test);
content.setSpan(new UnderlineSpan(), 0, test.length(), 0);
tvTest.setText(content);
但是,两种解决方案的文字和下划线指示符使用相同的颜色.我想知道是否可以以一种合理的方式更改下划线指示器的颜色,而不会出现如此处所示的任何背景XML和反射hacks
But both solutions use the same color for the text and the underline indicator. I want to know if I can change the color of the underline indicator in a sane way without any background XML and reflection hacks as seen here
我只想在文本上加下划线,而不是填充文字,下划线.我的文字也可以跨越多行,我希望每行都加下划线. (这是XML解决方案失败的地方.)
I want to underline only the text, not the paddings, margins. My text can span over multiple lines too, I want every line to be underlined. (This is where the XML solution fails).
我的代码的结果
Result of my code
推荐答案
回答我自己的问题感觉很奇怪,但是为了任何人遇到同样的问题,我都会这样做.在阅读其他有关此操作的帖子时,我偶然发现了 Layout 类EditText
.通过使用画布手动绘制下划线,它提供了实现此功能所需的一切.
It feels weird answering my own question, but for the sake of anyone having the same problem, I will. I have stumbled upon Layout class when reading some other posts for doing this on EditText
. It provides everything you need to make this happen by manually drawing underline with canvas.
首先,我定义了自定义属性,以便在XML布局文件中轻松自定义
First I defined custom attributes for an easy customization in XML layout files
<declare-styleable name="UnderlinedTextView" >
<attr name="underlineWidth" format="dimension" />
<attr name="underlineColor" format="color" />
</declare-styleable>
和一个自定义的TextView
类
public class UnderlinedTextView extends AppCompatTextView {
private Rect lineBoundsRect;
private Paint underlinePaint;
public UnderlinedTextView(Context context) {
this(context, null, 0);
}
public UnderlinedTextView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public UnderlinedTextView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context, attrs, defStyleAttr);
}
private void init(Context context, AttributeSet attributeSet, int defStyle) {
float density = context.getResources().getDisplayMetrics().density;
TypedArray typedArray = context.obtainStyledAttributes(attributeSet, R.styleable.UnderlinedTextView, defStyle, 0);
int mColor = typedArray.getColor(R.styleable.UnderlinedTextView_underlineColor, 0xFFFF0000);
float mStrokeWidth = typedArray.getDimension(R.styleable.UnderlinedTextView_underlineWidth, density * 2);
typedArray.recycle();
lineBoundsRect = new Rect();
underlinePaint = new Paint();
underlinePaint.setStyle(Paint.Style.STROKE);
underlinePaint.setColor(mColor); //color of the underline
underlinePaint.setStrokeWidth(mStrokeWidth);
}
@ColorInt
public int getUnderLineColor() {
return underlinePaint.getColor();
}
public void setUnderLineColor(@ColorInt int mColor) {
underlinePaint.setColor(mColor);
invalidate();
}
public float getUnderlineWidth() {
underlinePaint.getStrokeWidth()
}
public void setUnderlineWidth(float mStrokeWidth) {
underlinePaint.setStrokeWidth(mStrokeWidth);
invalidate();
}
@Override
protected void onDraw(Canvas canvas) {
int count = getLineCount();
final Layout layout = getLayout();
float x_start, x_stop, x_diff;
int firstCharInLine, lastCharInLine;
for (int i = 0; i < count; i++) {
int baseline = getLineBounds(i, lineBoundsRect);
firstCharInLine = layout.getLineStart(i);
lastCharInLine = layout.getLineEnd(i);
x_start = layout.getPrimaryHorizontal(firstCharInLine);
x_diff = layout.getPrimaryHorizontal(firstCharInLine + 1) - x_start;
x_stop = layout.getPrimaryHorizontal(lastCharInLine - 1) + x_diff;
canvas.drawLine(x_start, baseline + mStrokeWidth, x_stop, baseline + mStrokeWidth, underlinePaint);
}
super.onDraw(canvas);
}
}
然后它的用法很简单
<some.package.UnderlinedTextView
android:id="@+id/tvTest"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_marginBottom="10dp"
android:layout_marginLeft="20dp"
android:layout_marginRight="20dp"
android:gravity="center"
android:text="This is a demo text"
android:textSize="16sp"
app:underlineColor="#ffc112ef"
app:underlineWidth="3dp"/>
最终结果
- 多行
- 单行
- Multi line
- Single line
这篇关于更改TextView的下划线颜色的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!