地址
CSDN地址：http://blog.csdn.net/xiangyong_1521/article/details/78137394
当需要动态更改的TextView的内容字体的大小，比如设定的TextView的只有一行，宽度只有200dp，内容超过这个之后就缩小字体显示，只能能将字体都显示完全;也就是动态更改的的TextView的字体大小，当TextView的的的内容比较多时缩小显示，当TextView的中的内容比较少时正常显示
目录
- 图片展示
- 方法一：重写的TextView
- 方法二：使用框架Android的autofittextview
- 链接
一. 图片展示
可以看出来：当文字没有填充的TextView的完全时显示的就是默认的字体，当文字能够完全填充的TextView的并且一行显示不下时，他会默认的缩小文字的字体，当文字再多时，他会默认在末尾省略。
二. 方法一：重写的TextView
代码语言：javascript复制此类方法是在的TextView的onTextChanged和onSizeChanged下，根据获取的TextView可容纳的宽度来计算一个靠近可容纳的最大字体宽度，从而来给TextView的设置textsize。
public class CustomTextView extends TextView {
private static float DEFAULT_MIN_TEXT_SIZE = 1;
private static float DEFAULT_MAX_TEXT_SIZE = 48;
// Attributes
private Paint testPaint;
private float minTextSize, TextSize, maxTextSize;
public CustomTextView(Context context, AttributeSet attrs) {
super(context, attrs);
initialise();
}
private void initialise() {
/*
* limited size
*/
testPaint = new Paint();
testPaint.set(this.getPaint());
TextSize = this.getTextSize();
if (TextSize <= DEFAULT_MIN_TEXT_SIZE) {
TextSize = DEFAULT_MIN_TEXT_SIZE;
}
if (TextSize >= DEFAULT_MAX_TEXT_SIZE) {
TextSize = DEFAULT_MAX_TEXT_SIZE;
}
minTextSize = DEFAULT_MIN_TEXT_SIZE;
maxTextSize = DEFAULT_MAX_TEXT_SIZE;
};
/*
* (non-Javadoc)
* @see android.widget.TextView#onTextChanged(java.lang.CharSequence, int, int, int)
*/
@Override
protected void onTextChanged(CharSequence text, int start, int before,
int after) {
super.onTextChanged(text, start, before, after);
refitText(text.toString(), this.getWidth());
}
/*
* (non-Javadoc)
* @see android.view.View#onSizeChanged(int, int, int, int)
*/
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
if (w != oldw) {
refitText(this.getText().toString(), w);
}
}
//修改text方法
private void refitText(String text, int textWidth) {
if (textWidth > 0) {
int availableWidth = textWidth - this.getPaddingLeft()
- this.getPaddingRight();// 获取实际TextView的画布可用大小
float trySize = TextSize;
float scaled = getContext().getResources().getDisplayMetrics().scaledDensity*trySize; //dp转为px后的textsize
testPaint.setTextSize(scaled);
while ((trySize > minTextSize||trySize<maxTextSize)&&
(testPaint.measureText(text) > availableWidth)
) {
trySize -= 2; //减小2个单位大小
FontMetrics fm = testPaint.getFontMetrics();
float scaled1 = (float) (this.getHeight() / (Math.ceil(fm.descent - fm.top) 2));
float scaled2 = (float) ((testPaint.measureText(text) / availableWidth));
if (scaled1 >= 1.75 & scaled1 >= scaled2) {
break;
}
if (trySize <= minTextSize) {
trySize = minTextSize;
break;
}else if (trySize >= maxTextSize) {
trySize = maxTextSize;
break;
}
testPaint.setTextSize(trySize * scaled);
}
this.setTextSize(trySize);
}
};
}三. 方法二：使用框架Android的autofittextview
框架地址：HTTPS：//github.com/grantland/android-autofittextview
代码语言：javascript复制AutofitTextView：自定义的TextView的并继承系统的的TextView的，然后在绘制组件的时候根据getMaxLines方法获取内容的行数若内容的行数大于1，则缩小文字的字体，然后在尝试获取getMaxLines方法，若内容的行数还是大于1，则缩小文字的字体，直到内容能够一行显示或者是字体缩小大一定的大小，这时候若缩小到一定的大小还是不能一行显示，则尾部省略。
package me.grantland.widget;
import android.content.Context;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.TextView;
/**
* A {@link TextView} that re-sizes its text to be no larger than the width of the view.
*
* @attr ref R.styleable.AutofitTextView_sizeToFit
* @attr ref R.styleable.AutofitTextView_minTextSize
* @attr ref R.styleable.AutofitTextView_precision
*/
public class AutofitTextView extends TextView implements AutofitHelper.OnTextSizeChangeListener {
private AutofitHelper mHelper;
public AutofitTextView(Context context) {
super(context);
init(context, null, 0);
}
public AutofitTextView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context, attrs, 0);
}
public AutofitTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context, attrs, defStyle);
}
private void init(Context context, AttributeSet attrs, int defStyle) {
mHelper = AutofitHelper.create(this, attrs, defStyle)
.addOnTextSizeChangeListener(this);
}
// Getters and Setters
/**
* {@inheritDoc}
*/
@Override
public void setTextSize(int unit, float size) {
super.setTextSize(unit, size);
if (mHelper != null) {
mHelper.setTextSize(unit, size);
}
}
/**
* {@inheritDoc}
*/
@Override
public void setLines(int lines) {
super.setLines(lines);
if (mHelper != null) {
mHelper.setMaxLines(lines);
}
}
/**
* {@inheritDoc}
*/
@Override
public void setMaxLines(int maxLines) {
super.setMaxLines(maxLines);
if (mHelper != null) {
mHelper.setMaxLines(maxLines);
}
}
/**
* Returns the {@link AutofitHelper} for this View.
*/
public AutofitHelper getAutofitHelper() {
return mHelper;
}
/**
* Returns whether or not the text will be automatically re-sized to fit its constraints.
*/
public boolean isSizeToFit() {
return mHelper.isEnabled();
}
/**
* Sets the property of this field (sizeToFit), to automatically resize the text to fit its
* constraints.
*/
public void setSizeToFit() {
setSizeToFit(true);
}
/**
* If true, the text will automatically be re-sized to fit its constraints; if false, it will
* act like a normal TextView.
*
* @param sizeToFit
*/
public void setSizeToFit(boolean sizeToFit) {
mHelper.setEnabled(sizeToFit);
}
/**
* Returns the maximum size (in pixels) of the text in this View.
*/
public float getMaxTextSize() {
return mHelper.getMaxTextSize();
}
/**
* Set the maximum text size to the given value, interpreted as "scaled pixel" units. This size
* is adjusted based on the current density and user font size preference.
*
* @param size The scaled pixel size.
*
* @attr ref android.R.styleable#TextView_textSize
*/
public void setMaxTextSize(float size) {
mHelper.setMaxTextSize(size);
}
/**
* Set the maximum text size to a given unit and value. See TypedValue for the possible
* dimension units.
*
* @param unit The desired dimension unit.
* @param size The desired size in the given units.
*
* @attr ref android.R.styleable#TextView_textSize
*/
public void setMaxTextSize(int unit, float size) {
mHelper.setMaxTextSize(unit, size);
}
/**
* Returns the minimum size (in pixels) of the text in this View.
*/
public float getMinTextSize() {
return mHelper.getMinTextSize();
}
/**
* Set the minimum text size to the given value, interpreted as "scaled pixel" units. This size
* is adjusted based on the current density and user font size preference.
*
* @param minSize The scaled pixel size.
*
* @attr ref me.grantland.R.styleable#AutofitTextView_minTextSize
*/
public void setMinTextSize(int minSize) {
mHelper.setMinTextSize(TypedValue.COMPLEX_UNIT_SP, minSize);
}
/**
* Set the minimum text size to a given unit and value. See TypedValue for the possible
* dimension units.
*
* @param unit The desired dimension unit.
* @param minSize The desired size in the given units.
*
* @attr ref me.grantland.R.styleable#AutofitTextView_minTextSize
*/
public void setMinTextSize(int unit, float minSize) {
mHelper.setMinTextSize(unit, minSize);
}
/**
* Returns the amount of precision used to calculate the correct text size to fit within its
* bounds.
*/
public float getPrecision() {
return mHelper.getPrecision();
}
/**
* Set the amount of precision used to calculate the correct text size to fit within its
* bounds. Lower precision is more precise and takes more time.
*
* @param precision The amount of precision.
*/
public void setPrecision(float precision) {
mHelper.setPrecision(precision);
}
@Override
public void onTextSizeChange(float textSize, float oldTextSize) {
// do nothing
}
}
