NGUI扩展UITexture支持设置Texture的同时，动态修改对应材质的参数

NGUI的UITexture,可以单独设置渲染材质，但是动态设置材质球参数时候，发现总是不生效，看了下NGUI源码，发现其中的原因

UITexture中的UIDrawCall（对MeshRenderer的封装）并不是直接使用参数mMaterial，而是使用的mDynamicMat，所有的UIWiget设置的都是mMaterial，只有当RebuildMaterial()时才会把之前的mDynamicMat效果并以mMaterial重新new一遍，并拷贝当前mMaterial的所有属性，源码如下：

	Material RebuildMaterial ()
	{
		// Destroy the old material
		NGUITools.DestroyImmediate(mDynamicMat);

		// Create a new material
		CreateMaterial();
		mDynamicMat.renderQueue = mRenderQueue;

		// Update the renderer
		if (mRenderer != null)
		{
			mRenderer.sharedMaterials = new Material[] { mDynamicMat };
			mRenderer.sortingLayerName = mSortingLayerName;
			mRenderer.sortingOrder = mSortingOrder;
		}
		return mDynamicMat;
	}

但真正的问题出在CreateMaterial这个函数中的下面这段代码

if (mMaterial != null)
{
	mDynamicMat = new Material(mMaterial);
#if UNITY_EDITOR
	mDynamicMat.name = "[NGUI] " + mMaterial.name;
#else
	mDynamicMat.name = "[NGUI] ";
#endif
	mDynamicMat.hideFlags = (HideFlags.DontSave | HideFlags.NotEditable);
	mDynamicMat.CopyPropertiesFromMaterial(mMaterial);
#if !UNITY_FLASH
	string[] keywords = mMaterial.shaderKeywords;
	for (int i = 0; i < keywords.Length; ++i)
		mDynamicMat.EnableKeyword(keywords[i]);
#endif
	// If there is a valid shader, assign it to the custom material
	if (shader != null)
	{
		mDynamicMat.shader = shader;
	}
	else if (mClipCount != 0)
	{
		Debug.LogError(shaderName + " shader doesn't have a clipped shader version for " + mClipCount + " clip regions");
	}
}

这段代码最后一句 mDynamicMat.shader = shader; 会使先前的mDynamicMat.CopyPropertiesFromMaterial(mMaterial);之后的mDynamicMat参数重新变成默认值

以下是我通过对UITexture扩展的解决方案:

using UnityEngine;
using System.Collections.Generic;

public partial class UITexture
{
    /// <summary>
    /// 支持设置UITexture图片同时生效对图片处理的材质
    /// </summary>
	public void SetTextureEx(Texture texture, Material material)
	{
        if (mTexture != texture)
        {
            if (drawCall != null && drawCall.widgetCount == 1)
            {
                if (nullTexture == null)
                {
                    nullTexture = new Texture2D(1, 1, TextureFormat.ARGB32, false, true);
                    nullTexture.SetPixel(0, 0, Color.clear); 
                    nullTexture.Apply();
                }
                mTexture = texture ?? nullTexture;
                drawCall.mainTexture = texture ?? nullTexture;

                if (material != null)
                {
                    mMat = material;
                    if (drawCall.Renderer.material != material)
                        drawCall.Renderer.material = new Material(material);
                    drawCall.Renderer.material.CopyPropertiesFromMaterial(material);
                }
                else
                {
                    this.material = null;
                }
            }
        }
    }

}