给项目开发聊天输入框的时候，UGUI自带的InputField只能设置输入内容显示最新输入的内容和输入固定长度的内容，并没有自适应内容改变输入框的长度和宽度，针对此种问题，下面就分享下解决办法。
实现思路：
继承继承UGUI提供的Layout接口，根据接口提供的方法计算出输入内容的宽高，接口方法就能够自适应宽高。
实现效果：
实现代码：
<pre class="code" data-lang="javascript" style="box-sizing: border-box; margin: 0px; padding: 0px; white-space: pre-wrap;">using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;
[RequireComponent(typeof(InputField))]
public class InputFieldScaler : MonoBehaviour, ILayoutElement
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private Text textComponent
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get
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return this.GetComponent<InputField>().textComponent;
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public TextGenerationSettings GetTextGenerationSettings(Vector2 extents)
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var settings = textComponent.GetGenerationSettings(extents);
settings.generateOutOfBounds = true;
return settings;
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private RectTransform m_Rect;
private RectTransform rectTransform
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get
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if (m_Rect == null)
m_Rect = GetComponent<RectTransform>();
return m_Rect;
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public void OnValueChanged(string v)
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if (!fixedWidth)
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rectTransform.SetSizeWithCurrentAnchors((RectTransform.Axis)0, LayoutUtility.GetPreferredWidth(m_Rect));
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rectTransform.SetSizeWithCurrentAnchors((RectTransform.Axis)1, LayoutUtility.GetPreferredHeight(m_Rect));
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void OnEnable()
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this.inputField.onValueChanged.AddListener(OnValueChanged);
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void OnDisable()
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private Vector2 originalSize;
private InputField _inputField;
public InputField inputField
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get
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return _inputField ?? (_inputField = this.GetComponent<InputField>());
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private float _offsetHeight;
public float offsetHeight
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get
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if (_offsetHeight == 0)
_offsetHeight = generatorForLayout.GetPreferredHeight(text, GetTextGenerationSettings(Vector2.zero)) / textComponent.pixelsPerUnit;
return _offsetHeight;
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private float _offsetTextComponentLeftRingt;
public float offsetTextComponentLeftRingt
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get
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if (_offsetTextComponentLeftRingt == 0)
_offsetTextComponentLeftRingt = Mathf.Abs(rectTransform.rect.xMin - textComponent.rectTransform.rect.xMin) + Mathf.Abs(rectTransform.rect.xMax - textComponent.rectTransform.rect.xMax);
return _offsetTextComponentLeftRingt;
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protected void Awake()
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textComponent.fontSize = fontSize;
inputField.placeholder.GetComponent<Text>().fontSize = fontSize;
this.originalSize = this.GetComponent<RectTransform>().sizeDelta;
inputField.lineType = fixedWidth ? InputField.LineType.MultiLineNewline : InputField.LineType.SingleLine;
rectTransform.SetSizeWithCurrentAnchors((RectTransform.Axis)1, LayoutUtility.GetPreferredHeight(m_Rect));
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private string text
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get
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return this.GetComponent<InputField>().text;
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private TextGenerator _generatorForLayout;
public TextGenerator generatorForLayout
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get
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return _generatorForLayout ?? (_generatorForLayout = new TextGenerator());
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//[Tooltip("测试用")]
//public float Width;
//[Tooltip("测试用")]
//public float Height;
public void Update()
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//this.Width = this.preferredWidth;
//this.Height = this.preferredHeight;
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public float preferredWidth
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get
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if (fixedWidth)
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return this.originalSize.x;
//return Mathf.Max(this.originalSize.x, generatorForLayout.GetPreferredWidth(text, GetTextGenerationSettings(Vector2.zero)) / textComponent.pixelsPerUnit + 20);
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else
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if (keepInitWidthSize)
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return Mathf.Max(this.originalSize.x, generatorForLayout.GetPreferredWidth(text, GetTextGenerationSettings(Vector2.zero)) / textComponent.pixelsPerUnit + offsetTextComponentLeftRingt);
//return generatorForLayout.GetPreferredWidth(text, GetTextGenerationSettings(Vector2.zero)) / textComponent.pixelsPerUnit + 20;
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else
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return generatorForLayout.GetPreferredWidth(text, GetTextGenerationSettings(Vector2.zero)) / textComponent.pixelsPerUnit + offsetTextComponentLeftRingt;
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public virtual void CalculateLayoutInputHorizontal()
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public virtual void CalculateLayoutInputVertical()
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public virtual float minWidth
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get ｛ return -1; ｝
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public virtual float flexibleWidth ｛ get ｛ return -1; ｝ ｝
public virtual float minHeight
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get ｛ return -1; ｝
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public virtual float preferredHeight
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get
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if (fixedWidth)
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return generatorForLayout.GetPreferredHeight(text, GetTextGenerationSettings(new Vector2(this.textComponent.GetPixelAdjustedRect().size.x, 0.0f))) / textComponent.pixelsPerUnit + offsetHeight;
//return Mathf.Max(this.originalSize.y, generatorForLayout.GetPreferredHeight(text, GetTextGenerationSettings(new Vector2(this.textComponent.GetPixelAdjustedRect().size.x, 0.0f))) / textComponent.pixelsPerUnit);
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else
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return generatorForLayout.GetPreferredHeight(text, GetTextGenerationSettings(new Vector2(this.textComponent.GetPixelAdjustedRect().size.x, 0.0f))) / textComponent.pixelsPerUnit + offsetHeight;
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public virtual float flexibleHeight ｛ get ｛ return -1; ｝ ｝
//[Tooltip("输入框的字体大小，InputField的大小会随字体大小改变高度")]
[HideInInspector]
public int fontSize = 20;
//[Tooltip("是否保持InputField的宽度不变")]
[HideInInspector]
public bool fixedWidth = true;
//[Tooltip("是否不限制InputField的宽度")]
[HideInInspector]
public bool keepInitWidthSize = true;
//[SerializeField]
//[Tooltip("提高Layout计算优先级，要比InputField大 这里设为1")]
private int priority = 1;
public virtual int layoutPriority ｛ get ｛ return priority; ｝ ｝
｝</pre>
代码其实很简单，就是通过输入的字符串的内容，在接口方法里计算出宽高就可以了，接口方法会被自动调用。
下载链接：https://pan.baidu.com/s/1ggHYtAr 密码：98rp
