假设您有一个普通的 TextView,其中写有“Stackoverflow”,是否可以将 TextView 旋转 -90°,使 S 位于屏幕底部,W 位于屏幕顶部?当然,我可以将我的文本写成图像,旋转它并以这种方式使用它,但我现在对文本感兴趣。谢谢。
10 回答
您可以像往常一样设置文本视图
例如:
<TextView android:id="@+id/txtview"
android:layout_height="fill_parent"
android:layout_width="wrap_content" />
并在您的活动中编写一个函数
- 反转文本中的字符
\n
在每个字符之后插入
然后将文本设置为 TextView。
如果您不想插入\n
,则必须设置android:layout_width
字体大小并使用字体大小不让 2 个字符适合同一行且不截断
编辑 如果我对你的理解正确,你可以通过使用动画来得到你想要的。
例如
下res/anim/myanim.xml
:
<rotate xmlns:android="http://schemas.android.com/apk/res/android"
android:fromDegrees="0"
android:toDegrees="-90"
android:pivotX="50%"
android:duration="0" />
您将不得不使用此文件来定义您希望放置文本视图的位置。
在您的活动中:
TextView t = (TextView)findViewById(R.id.txtview);
String txt = "Stackoverflow";
t.setText(txt);
RotateAnimation ranim = (RotateAnimation)AnimationUtils.loadAnimation(this, R.anim.myanim);
ranim.setFillAfter(true); //For the textview to remain at the same place after the rotation
t.setAnimation(ranim);
为我工作:
public class VerticalTextView extends TextView {
private int _width, _height;
private final Rect _bounds = new Rect();
public VerticalTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public VerticalTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public VerticalTextView(Context context) {
super(context);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
// vise versa
_height = getMeasuredWidth();
_width = getMeasuredHeight();
setMeasuredDimension(_width, _height);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.save();
canvas.translate(_width, _height);
canvas.rotate(-90);
TextPaint paint = getPaint();
paint.setColor(getTextColors().getDefaultColor());
String text = text();
paint.getTextBounds(text, 0, text.length(), _bounds);
canvas.drawText(text, getCompoundPaddingLeft(), (_bounds.height() - _width) / 2, paint);
canvas.restore();
}
private String text() {
return super.getText().toString();
}
}
xml:
<VerticalTextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="left|center_vertical"
android:background="@color/feedback_background"
android:padding="4dip"
android:text="@string/feedback"
android:textColor="@color/feedback_text_color"
android:textSize="@dimen/text_xlarge" />
<TextView
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:text="xyz"
android:rotation="-90"
android:gravity="fill_vertical"/>
试试这个。这对我来说可以。它可以垂直显示一行文本,但只能显示一行。颜色、大小、填充、边距和背景都可以正常工作。
public class VerticalTextView extends TextView {
public VerticalTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public VerticalTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public VerticalTextView(Context context) {
super(context);
}
@Override
protected void onDraw(Canvas canvas) {
final ColorStateList csl = getTextColors();
final int color = csl.getDefaultColor();
final int paddingBottom = getPaddingBottom();
final int paddingTop = getPaddingTop();
final int viewWidth = getWidth();
final int viewHeight = getHeight();
final TextPaint paint = getPaint();
paint.setColor(color);
final float bottom = viewWidth * 9.0f / 11.0f;
Path p = new Path();
p.moveTo(bottom, viewHeight - paddingBottom - paddingTop);
p.lineTo(bottom, paddingTop);
canvas.drawTextOnPath(getText().toString(), p, 0, 0, paint);
}
}
如果您使用的是 API 11 或更高版本,您可以尝试:
TextView t = (TextView) findViewById(R.id.txtview);
String txt = "Stackoverflow";
t.setText(txt);
t.setRotation(90); // 90 degree rotation
我将向你们展示我的自定义垂直按钮示例,其中包含旋转的 TextView:
<!--Undo button-->
<LinearLayout
android:id="@+id/undo_points_pr_a"
android:layout_width="@dimen/zero_dp"
android:gravity="center"
android:layout_height="match_parent"
android:orientation="vertical"
android:layout_weight="1"
android:background="@color/timerUndoButton">
<ImageView
android:layout_width="@dimen/large"
android:layout_height="@dimen/large"
android:src="@drawable/undo_icon"
android:rotation="-90"
android:layout_marginBottom="@dimen/medium"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/undo"
android:textSize="@dimen/small_medium_text"
android:rotation="-90"/>
</LinearLayout>
这就是它在 Android Studio 中的样子:
当然,您必须修改此代码以使其适合您。(在 android:layout_width、android:layout_height 等属性中)
我在另一个 StackOverflow问题中提供了解决方案。您可以通过从 View 扩展并覆盖其onMeasure()
和onDraw()
方法来获得垂直 TextView。但是,它不会支持所有 TextView 功能,而是支持它的主要功能,如填充、大小、颜色和字体。
import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.os.Build;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
public class VerticalLabelView extends View
{
private final String LOG_TAG = "VerticalLabelView";
private final int DEFAULT_TEXT_SIZE = 30;
private int _ascent = 0;
private int _leftPadding = 0;
private int _topPadding = 0;
private int _rightPadding = 0;
private int _bottomPadding = 0;
private int _textSize = 0;
private int _measuredWidth;
private int _measuredHeight;
private Rect _textBounds;
private TextPaint _textPaint;
private String _text = "";
private TextView _tempView;
private Typeface _typeface = null;
private boolean _topToDown = false;
public VerticalLabelView(Context context)
{
super(context);
initLabelView();
}
public VerticalLabelView(Context context, AttributeSet attrs)
{
super(context, attrs);
initLabelView();
}
public VerticalLabelView(Context context, AttributeSet attrs, int defStyleAttr)
{
super(context, attrs, defStyleAttr);
initLabelView();
}
@TargetApi(Build.VERSION_CODES.LOLLIPOP)
public VerticalLabelView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)
{
super(context, attrs, defStyleAttr, defStyleRes);
initLabelView();
}
private final void initLabelView()
{
this._textBounds = new Rect();
this._textPaint = new TextPaint();
this._textPaint.setAntiAlias(true);
this._textPaint.setTextAlign(Paint.Align.CENTER);
this._textPaint.setTextSize(DEFAULT_TEXT_SIZE);
this._textSize = DEFAULT_TEXT_SIZE;
}
public void setText(String text)
{
this._text = text;
requestLayout();
invalidate();
}
public void topToDown(boolean topToDown)
{
this._topToDown = topToDown;
}
public void setPadding(int padding)
{
setPadding(padding, padding, padding, padding);
}
public void setPadding(int left, int top, int right, int bottom)
{
this._leftPadding = left;
this._topPadding = top;
this._rightPadding = right;
this._bottomPadding = bottom;
requestLayout();
invalidate();
}
public void setTextSize(int size)
{
this._textSize = size;
this._textPaint.setTextSize(size);
requestLayout();
invalidate();
}
public void setTextColor(int color)
{
this._textPaint.setColor(color);
invalidate();
}
public void setTypeFace(Typeface typeface)
{
this._typeface = typeface;
this._textPaint.setTypeface(typeface);
requestLayout();
invalidate();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
try
{
this._textPaint.getTextBounds(this._text, 0, this._text.length(), this._textBounds);
this._tempView = new TextView(getContext());
this._tempView.setPadding(this._leftPadding, this._topPadding, this._rightPadding, this._bottomPadding);
this._tempView.setText(this._text);
this._tempView.setTextSize(TypedValue.COMPLEX_UNIT_PX, this._textSize);
this._tempView.setTypeface(this._typeface);
this._tempView.measure(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
this._measuredWidth = this._tempView.getMeasuredHeight();
this._measuredHeight = this._tempView.getMeasuredWidth();
this._ascent = this._textBounds.height() / 2 + this._measuredWidth / 2;
setMeasuredDimension(this._measuredWidth, this._measuredHeight);
}
catch (Exception e)
{
setMeasuredDimension(widthMeasureSpec, heightMeasureSpec);
Log.e(LOG_TAG, Log.getStackTraceString(e));
}
}
@Override
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
if (!this._text.isEmpty())
{
float textHorizontallyCenteredOriginX = this._measuredHeight / 2f;
float textHorizontallyCenteredOriginY = this._ascent;
canvas.translate(textHorizontallyCenteredOriginY, textHorizontallyCenteredOriginX);
float rotateDegree = -90;
float y = 0;
if (this._topToDown)
{
rotateDegree = 90;
y = this._measuredWidth / 2;
}
canvas.rotate(rotateDegree);
canvas.drawText(this._text, 0, y, this._textPaint);
}
}
}
我认为垂直编写“Stackoverflow”的问题的最简单答案是使用普通的 TextView,并且由于文本在变窄时会换行到下一行,因此请使用 TextView 的宽度,以便每个字母都有一个行,如果您需要在边缘有更多空间作为缓冲区,请增加 TextView 的“填充”和/或“边距”。
我最初在垂直 LinearLayout 中呈现垂直文本的方法如下(这是 Kotlin,在 Java 中使用setRoatation
等):
val tv = TextView(context)
tv.gravity = Gravity.CENTER
tv.rotation = 90F
tv.height = calcHeight(...)
linearLabels.addView(tv)
正如您所看到的,问题在于 TextView 垂直但仍将其宽度视为水平方向!=/
因此方法#2包括额外手动切换宽度和高度来解决这个问题:
tv.measure(0, 0)
// tv.setSingleLine()
tv.width = tv.measuredHeight
tv.height = calcHeight(...)
setSingleLine
然而,这导致标签在相对较短的宽度之后环绕到下一行(或者被裁剪)。同样,这归结为将 x 与 y 混淆。
因此,我的方法#3 是将 TextView 包装在 RelativeLayout 中。这个想法是通过将 TextView 向左和向右(这里,在两个方向上 200 像素)延伸很远来允许 TextView 任何它想要的宽度。但后来我给 RelativeLayout 负边距以确保它被绘制为一个窄列。这是此屏幕截图的完整代码:
val tv = TextView(context)
tv.text = getLabel(...)
tv.gravity = Gravity.CENTER
tv.rotation = 90F
tv.measure(0, 0)
tv.width = tv.measuredHeight + 400 // 400 IQ
tv.height = calcHeight(...)
val tvHolder = RelativeLayout(context)
val lp = LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT)
lp.setMargins(-200, 0, -200, 0)
tvHolder.layoutParams = lp
tvHolder.addView(tv)
linearLabels.addView(tvHolder)
val iv = ImageView(context)
iv.setImageResource(R.drawable.divider)
linearLabels.addView(iv)
作为一般提示,这种让视图“持有”另一个视图的策略对我在 Android 中定位事物非常有用!例如,ActionBar 下方的信息窗口使用相同的策略!
对于从底部开始的文本,只需将其旋转 -90F 而不是 90F 度。
public class VerticalTextView extends AppCompatTextView {
final boolean topDown;
public VerticalTextView(Context context, AttributeSet attrs) {
super(context, attrs);
final int gravity = getGravity();
if (Gravity.isVertical(gravity) && (gravity & Gravity.VERTICAL_GRAVITY_MASK) == Gravity.BOTTOM) {
setGravity((gravity & Gravity.HORIZONTAL_GRAVITY_MASK) | Gravity.TOP);
topDown = false;
} else
topDown = true;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(heightMeasureSpec, widthMeasureSpec);
setMeasuredDimension(getMeasuredHeight(), getMeasuredWidth());
}
@Override
protected void onDraw(Canvas canvas) {
TextPaint textPaint = getPaint();
textPaint.setColor(getCurrentTextColor());
textPaint.drawableState = getDrawableState();
canvas.save();
if (topDown) {
canvas.translate(getWidth(), 0);
canvas.rotate(90);
} else {
canvas.translate(0, getHeight());
canvas.rotate(-90);
}
canvas.translate(getCompoundPaddingLeft(), getExtendedPaddingTop());
getLayout().draw(canvas);
canvas.restore();
}
}