作者:尛丶俊_188 | 来源:互联网 | 2023-05-16 06:43
项目中一般会遇到特殊的TextView,比如保证文字的左右对齐,首行缩进啦,这样的话系统定制的TextView就无法满足要求了,需要我们自定义WordTextView。
直接上效果图:
![这里写图片描述](https://www.#.com/go/aHR0cDovL2ltZy5ibG9nLmNzZG4ubmV0LzIwMTcwNzA5MTUzMjUyOTQ0P3dhdGVybWFyay8yL3RleHQvYUhSMGNEb3ZMMkpzYjJjdVkzTmtiaTV1WlhRdlRHOXphVzVuUTJGeWNubEthV1U9L2ZvbnQvNWE2TDVMMlQvZm9udHNpemUvNDAwL2ZpbGwvSTBKQlFrRkNNQT09L2Rpc3NvbHZlLzcwL2dyYXZpdHkvU291dGhFYXN0)
上面的是系统的TextView,下面的是WordTextView
package com.views;
import android.content.Context;
import android.graphics.Canvas;
import android.text.Layout;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.widget.TextView;
/**
* By Jie 2017.7.9
*
* Word排版文本View
*
* 首行缩进,左右对齐TextView
*/
public class WordTextView extends TextView {
private int mLineY;
private int mViewWidth;
private int mViewHeight;
public WordTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if(MeasureSpec.getMode(widthMeasureSpec)==MeasureSpec.EXACTLY&&MeasureSpec.getMode(heightMeasureSpec)==MeasureSpec.EXACTLY){
return;
}
Layout layout = getLayout();
mViewHeight =0;
mViewWidth = layout.getWidth()+getPaddingLeft()+getPaddingRight();
for (int i = 0; i mViewHeight += getLineHeight();
}
mViewHeight = mViewHeight + getPaddingTop() + getPaddingBottom();
setMeasuredDimension(mViewWidth,mViewHeight);
}
/**
*
* 整体思路如下:
*
* 1 确定整个文本有多少行
*
* 2 重新绘制每一行的文本保证能左右对齐,或者首行缩进
*
* 3 最后一行正常绘制,因为他没有下一行,不一定要设置右对齐了
* @param canvas
*/
@Override
protected void onDraw(Canvas canvas) {
TextPaint paint = getPaint();
mViewWidth = getMeasuredWidth();
String text = (String) getText();
mLineY = 0;
mLineY += getTextSize()*1.5;
Layout layout = getLayout();
for (int i = 0; i int lineStart = layout.getLineStart(i);
int lineEnd = layout.getLineEnd(i);
String line = text.substring(lineStart, lineEnd);
float width = StaticLayout.getDesiredWidth(text, lineStart, lineEnd, getPaint());
if (needScale(line) && i 1
) {
drawScaledText(canvas,line, width,i);
}
else {
canvas.drawText(line,
0, mLineY, paint);
}
mLineY += getLineHeight();
}
}
/**
* 思路如下:
*
* 举个例子,屏幕宽度100,文本90,要想让文本填充整个屏幕怎么办呢?
* 很简单,让文本字符间隔填充剩下的10,还是不懂?
* 假如文本有10个字符,那么我让每个字符绘制的时候都和上一个字符间隔多1,那么正好文本宽度就成了(90+10=100)可以左右对齐屏幕了
* @param canvas
* @param line
* @param lineWidth
* @param index
*/ private void drawScaledText(Canvas canvas,String line,
float lineWidth,
int index) {
float x =
0;
if (isFirstLineOfParagraph(index)) {
String blanks =
" ";
canvas.drawText(blanks, x, mLineY, getPaint());
float bw = StaticLayout.getDesiredWidth(blanks, getPaint());
x += bw;
lineWidth = lineWidth +bw;
}
float d = (mViewWidth-lineWidth) /line.length();
for (
int i =
0; i
String c = String.valueOf(line.charAt(i));
float cw = StaticLayout.getDesiredWidth(c, getPaint());
canvas.drawText(c, x, mLineY, getPaint());
x += cw+d;
}
}
private boolean isFirstLineOfParagraph(int lineIndex) {
return lineIndex==0;
}
private boolean needScale(String line) {
if (line.length() == 0) {
return false;
} else {
return line.charAt(line.length() - 1) != '\n';
}
}
}