如何在 TextView 文本中添加图像?

我在谷歌上搜索了一下,发现这个网站上有一个类似的问题: 如何在 TextView文本中包含一个图像,例如 “你好,我叫[图片]”,答案是:

ImageSpan is = new ImageSpan(context, resId);
text.setSpan(is, index, index + strLength, 0);

我想知道在这个代码中,

  1. 在上下文中我应该打什么字或做什么?
  2. 我是否应该对 text.setSpan()做一些事情,比如导入或引用,或者留下文本?

如果有人能帮我解释一下,我将不胜感激。

195609 次浏览

Try this ..

    txtview.setCompoundDrawablesWithIntrinsicBounds(
R.drawable.image, 0, 0, 0);

Also see this.. http://developer.android.com/reference/android/widget/TextView.html

Try this in xml file

    <TextView
android:id="@+id/txtStatus"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:drawableLeft="@drawable/image"
android:drawablePadding="5dp"
android:maxLines="1"
android:text="@string/name"/>

com/xyz/customandroid/ TextViewWithImages .java:

import java.util.regex.Matcher;
import java.util.regex.Pattern;


import android.content.Context;
import android.text.Spannable;
import android.text.style.ImageSpan;
import android.util.AttributeSet;
import android.util.Log;
import android.widget.TextView;


public class TextViewWithImages extends TextView {


public TextViewWithImages(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public TextViewWithImages(Context context, AttributeSet attrs) {
super(context, attrs);
}
public TextViewWithImages(Context context) {
super(context);
}
@Override
public void setText(CharSequence text, BufferType type) {
Spannable s = getTextWithImages(getContext(), text);
super.setText(s, BufferType.SPANNABLE);
}


private static final Spannable.Factory spannableFactory = Spannable.Factory.getInstance();


private static boolean addImages(Context context, Spannable spannable) {
Pattern refImg = Pattern.compile("\\Q[img src=\\E([a-zA-Z0-9_]+?)\\Q/]\\E");
boolean hasChanges = false;


Matcher matcher = refImg.matcher(spannable);
while (matcher.find()) {
boolean set = true;
for (ImageSpan span : spannable.getSpans(matcher.start(), matcher.end(), ImageSpan.class)) {
if (spannable.getSpanStart(span) >= matcher.start()
&& spannable.getSpanEnd(span) <= matcher.end()
) {
spannable.removeSpan(span);
} else {
set = false;
break;
}
}
String resname = spannable.subSequence(matcher.start(1), matcher.end(1)).toString().trim();
int id = context.getResources().getIdentifier(resname, "drawable", context.getPackageName());
if (set) {
hasChanges = true;
spannable.setSpan(  new ImageSpan(context, id),
matcher.start(),
matcher.end(),
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
);
}
}


return hasChanges;
}
private static Spannable getTextWithImages(Context context, CharSequence text) {
Spannable spannable = spannableFactory.newSpannable(text);
addImages(context, spannable);
return spannable;
}
}

Use:

in res/layout/mylayout.xml:

            <com.xyz.customandroid.TextViewWithImages
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#FFFFFF00"
android:text="@string/can_try_again"
android:textSize="12dip"
style=...
/>

Note that if you place TextViewWithImages.java in some location other than com/xyz/customandroid/, you also must change the package name, com.xyz.customandroid above.

in res/values/strings.xml:

<string name="can_try_again">Press [img src=ok16/] to accept or [img src=retry16/] to retry</string>

where ok16.png and retry16.png are icons in the res/drawable/ folder

This answer is based on this excellent answer by 18446744073709551615. Their solution, though helpful, does not size the image icon with the surrounding text. It also doesn't set the icon colour to that of the surrounding text.

The solution below takes a white, square icon and makes it fit the size and colour of the surrounding text.

public class TextViewWithImages extends TextView {


private static final String DRAWABLE = "drawable";
/**
* Regex pattern that looks for embedded images of the format: [img src=imageName/]
*/
public static final String PATTERN = "\\Q[img src=\\E([a-zA-Z0-9_]+?)\\Q/]\\E";


public TextViewWithImages(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}


public TextViewWithImages(Context context, AttributeSet attrs) {
super(context, attrs);
}


public TextViewWithImages(Context context) {
super(context);
}


@Override
public void setText(CharSequence text, BufferType type) {
final Spannable spannable = getTextWithImages(getContext(), text, getLineHeight(), getCurrentTextColor());
super.setText(spannable, BufferType.SPANNABLE);
}


private static Spannable getTextWithImages(Context context, CharSequence text, int lineHeight, int colour) {
final Spannable spannable = Spannable.Factory.getInstance().newSpannable(text);
addImages(context, spannable, lineHeight, colour);
return spannable;
}


private static boolean addImages(Context context, Spannable spannable, int lineHeight, int colour) {
final Pattern refImg = Pattern.compile(PATTERN);
boolean hasChanges = false;


final Matcher matcher = refImg.matcher(spannable);
while (matcher.find()) {
boolean set = true;
for (ImageSpan span : spannable.getSpans(matcher.start(), matcher.end(), ImageSpan.class)) {
if (spannable.getSpanStart(span) >= matcher.start()
&& spannable.getSpanEnd(span) <= matcher.end()) {
spannable.removeSpan(span);
} else {
set = false;
break;
}
}
final String resName = spannable.subSequence(matcher.start(1), matcher.end(1)).toString().trim();
final int id = context.getResources().getIdentifier(resName, DRAWABLE, context.getPackageName());
if (set) {
hasChanges = true;
spannable.setSpan(makeImageSpan(context, id, lineHeight, colour),
matcher.start(),
matcher.end(),
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
);
}
}
return hasChanges;
}


/**
* Create an ImageSpan for the given icon drawable. This also sets the image size and colour.
* Works best with a white, square icon because of the colouring and resizing.
*
* @param context       The Android Context.
* @param drawableResId A drawable resource Id.
* @param size          The desired size (i.e. width and height) of the image icon in pixels.
*                      Use the lineHeight of the TextView to make the image inline with the
*                      surrounding text.
* @param colour        The colour (careful: NOT a resource Id) to apply to the image.
* @return An ImageSpan, aligned with the bottom of the text.
*/
private static ImageSpan makeImageSpan(Context context, int drawableResId, int size, int colour) {
final Drawable drawable = context.getResources().getDrawable(drawableResId);
drawable.mutate();
drawable.setColorFilter(colour, PorterDuff.Mode.MULTIPLY);
drawable.setBounds(0, 0, size, size);
return new ImageSpan(drawable, ImageSpan.ALIGN_BOTTOM);
}


}

How to use:

Simply embed references to the desired icons in the text. It doesn't matter whether the text is set programatically through textView.setText(R.string.string_resource); or if it's set in xml.

To embed a drawable icon named example.png, include the following string in the text: [img src=example/].

For example, a string resource might look like this:

<string name="string_resource">This [img src=example/] is an icon.</string>

I tried many different solutions and this for me was the best:

SpannableStringBuilder ssb = new SpannableStringBuilder(" Hello world!");
ssb.setSpan(new ImageSpan(context, R.drawable.image), 0, 1, Spannable.SPAN_INCLUSIVE_INCLUSIVE);
tv_text.setText(ssb, TextView.BufferType.SPANNABLE);

This code uses a minimum of memory.

This is partly based on this earlier answer above by @A Boschman. In that solution, I found that the input size of the image greatly affected the ability of makeImageSpan() to properly center-align the image. Additionally, I found that the solution affected text spacing by creating unnecessary line spacing.

I found BaseImageSpan (from Facebook's Fresco library) to do the job particularly well:

 /**
* Create an ImageSpan for the given icon drawable. This also sets the image size. Works best
* with a square icon because of the sizing
*
* @param context       The Android Context.
* @param drawableResId A drawable resource Id.
* @param size          The desired size (i.e. width and height) of the image icon in pixels.
*                      Use the lineHeight of the TextView to make the image inline with the
*                      surrounding text.
* @return An ImageSpan, aligned with the bottom of the text.
*/
private static BetterImageSpan makeImageSpan(Context context, int drawableResId, int size) {
final Drawable drawable = context.getResources().getDrawable(drawableResId);
drawable.mutate();
drawable.setBounds(0, 0, size, size);
return new BetterImageSpan(drawable, BetterImageSpan.ALIGN_CENTER);
}

Then supply your betterImageSpan instance to spannable.setSpan() as usual

This might Help You

  SpannableStringBuilder ssBuilder;


ssBuilder = new SpannableStringBuilder(" ");
// working code ImageSpan image = new ImageSpan(textView.getContext(), R.drawable.image);
Drawable image = ContextCompat.getDrawable(textView.getContext(), R.drawable.image);
float scale = textView.getContext().getResources().getDisplayMetrics().density;
int width = (int) (12 * scale + 0.5f);
int height = (int) (18 * scale + 0.5f);
image.setBounds(0, 0, width, height);
ImageSpan imageSpan = new ImageSpan(image, ImageSpan.ALIGN_BASELINE);
ssBuilder.setSpan(
imageSpan, // Span to add
0, // Start of the span (inclusive)
1, // End of the span (exclusive)
Spanned.SPAN_INCLUSIVE_EXCLUSIVE);// Do not extend the span when text add later


ssBuilder.append(" " + text);
ssBuilder = new SpannableStringBuilder(text);
textView.setText(ssBuilder);
fun TextView.addImage(atText: String, @DrawableRes imgSrc: Int, imgWidth: Int, imgHeight: Int) {
val ssb = SpannableStringBuilder(this.text)


val drawable = ContextCompat.getDrawable(this.context, imgSrc) ?: return
drawable.mutate()
drawable.setBounds(0, 0,
imgWidth,
imgHeight)
val start = text.indexOf(atText)
ssb.setSpan(VerticalImageSpan(drawable), start, start + atText.length, Spannable.SPAN_INCLUSIVE_EXCLUSIVE)
this.setText(ssb, TextView.BufferType.SPANNABLE)
}

VerticalImageSpan class from great answer https://stackoverflow.com/a/38788432/5381331

Using

val textView = findViewById<TextView>(R.id.textview)
textView.setText("Send an [email-icon] to example@email.com.")
textView.addImage("[email-icon]", R.drawable.ic_email,
resources.getDimensionPixelOffset(R.dimen.dp_30),
resources.getDimensionPixelOffset(R.dimen.dp_30))

Result

Note
Why VerticalImageSpan class?
ImageSpan.ALIGN_CENTER attribute requires API 29.
Also, after the test, I see that ImageSpan.ALIGN_CENTER only work if the image smaller than the text, if the image bigger than the text then only image is in center, text not center, it align on bottom of image

Let's say it is our TextView

<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:drawablePadding="4dp"
android:drawableRight="@drawable/edit"
android:text="Hello world"
android:textSize="18dp" />

Now we can add any one of the following lines to it as per our requirement

android:drawableLeft="@drawable/filename"
android:drawableRight="@drawable/filename"
android:drawableTop="@drawable/filename"
android:drawableBottom="@drawable/filename"

Did a component specifically for adding inline an Image inline to a text. it supports any given position and handles click on Image: https://github.com/myDario/DarioInlineImageTextView