只需将此组件添加到画布中的空对象即可。请注意，仅支持简单 图像类型。
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Sprites;
using UnityEngine.UI;
#if UNITY_2017_4 || UNITY_2018_2_OR_NEWER
using UnityEngine.U2D;
#endif
#if UNITY_EDITOR
using UnityEditor;
// Custom Editor to order the variables in the Inspector similar to Image component
[CustomEditor( typeof( PaddingIgnoringImage ) )]
[CanEditMultipleObjects]
public class PaddingIgnoringImageEditor : Editor
{
private SerializedProperty colorProp, spriteProp, preserveAspectProp, useSpriteMeshProp;
private GUIContent spriteLabel;
private void OnEnable()
{
colorProp = serializedObject.FindProperty( "m_Color" );
spriteProp = serializedObject.FindProperty( "m_Sprite" );
useSpriteMeshProp = serializedObject.FindProperty( "m_UseSpriteMesh" );
preserveAspectProp = serializedObject.FindProperty( "m_PreserveAspect" );
spriteLabel = new GUIContent( "Source Image" );
}
public override void OnInspectorGUI()
{
serializedObject.Update();
EditorGUILayout.PropertyField( colorProp );
EditorGUILayout.PropertyField( spriteProp, spriteLabel );
bool spriteAssigned = spriteProp.objectReferenceValue || spriteProp.hasMultipleDifferentValues;
if( spriteAssigned )
{
EditorGUI.indentLevel++;
EditorGUILayout.PropertyField( useSpriteMeshProp );
EditorGUILayout.PropertyField( preserveAspectProp );
EditorGUI.indentLevel--;
}
DrawPropertiesExcluding( serializedObject, "m_Script", "m_Color", "m_Sprite", "m_PreserveAspect", "m_UseSpriteMesh", "m_OnCullStateChanged" );
serializedObject.ApplyModifiedProperties();
if( spriteAssigned && GUILayout.Button( "Set Native Size", EditorStyles.miniButton ) )
{
foreach( Object target in targets )
{
PaddingIgnoringImage _target = target as PaddingIgnoringImage;
if( _target )
{
Undo.RecordObject( _target.rectTransform, "Set Native Size" );
_target.SetNativeSize();
EditorUtility.SetDirty( _target );
}
}
}
}
}
#endif
// Most of this code is a copy&paste of Unity's UnityEngine.UI.Image.cs
[RequireComponent( typeof( CanvasRenderer ) )]
public class PaddingIgnoringImage : MaskableGraphic, ILayoutElement
{
[SerializeField]
private Sprite m_Sprite;
public Sprite sprite
{
get {
return m_Sprite; }
set
{
if( m_Sprite )
{
if( m_Sprite != value )
{
m_Sprite = value;
SetAllDirty();
TrackImage();
}
}
else if( value )
{
m_Sprite = value;
SetAllDirty();
TrackImage();
}
}
}
[SerializeField]
private bool m_PreserveAspect;
public bool preserveAspect
{
get {
return m_PreserveAspect; }
set {
if( m_PreserveAspect != value ) {
m_PreserveAspect = value; SetVerticesDirty(); } }
}
[SerializeField]
private bool m_UseSpriteMesh;
public bool useSpriteMesh
{
get {
return m_UseSpriteMesh; }
set {
if( m_UseSpriteMesh != value ) {
m_UseSpriteMesh = value; SetVerticesDirty(); } }
}
public override Texture mainTexture {
get {
return sprite ? sprite.texture : s_WhiteTexture; } }
public float pixelsPerUnit
{
get
{
float spritePixelsPerUnit = 100;
if( sprite )
spritePixelsPerUnit = sprite.pixelsPerUnit;
float referencePixelsPerUnit = 100;
if( canvas )
referencePixelsPerUnit = canvas.referencePixelsPerUnit;
return spritePixelsPerUnit / referencePixelsPerUnit;
}
}
public override Material material
{
get
{
if( m_Material != null )
return m_Material;
if( sprite && sprite.associatedAlphaSplitTexture != null )
{
#if UNITY_EDITOR
if( Application.isPlaying )
#endif
return Image.defaultETC1GraphicMaterial;
}
return defaultMaterial;
}
set {
base.material = value; }
}
protected override void OnEnable()
{
base.OnEnable();
TrackImage();
}
protected override void OnDisable()
{
base.OnDisable();
if( m_Tracked )
UnTrackImage();
}
private Vector4 GetDrawingDimensions()
{
Vector4 padding = sprite ? DataUtility.GetPadding( sprite ) : Vector4.zero;
Vector2 size = sprite ? sprite.rect.size : Vector2.zero;
size -= new Vector2( padding.x + padding.z, padding.y + padding.w );
Rect r = GetPixelAdjustedRect();
if( preserveAspect && size.sqrMagnitude > 0f )
{
float spriteRatio = size.x / size.y;
float rectRatio = r.width / r.height;
if( spriteRatio > rectRatio )
{
float oldHeight = r.height;
r.height = r.width * ( 1f / spriteRatio );
r.y += ( oldHeight - r.height ) * rectTransform.pivot.y;
}
else
{
float oldWidth = r.width;
r.width = r.height * spriteRatio;
r.x += ( oldWidth - r.width ) * rectTransform.pivot.x;
}
}
return new Vector4( r.x, r.y, r.x + r.width, r.y + r.height );
}
protected override void OnPopulateMesh( VertexHelper vh )
{
vh.Clear();
Vector4 v = GetDrawingDimensions();
Vector4 uv = sprite ? DataUtility.GetOuterUV( sprite ) : Vector4.zero;
Color32 color32 = color;
if( !sprite || !useSpriteMesh )
{
vh.AddVert( new Vector3( v.x, v.y ), color32, new Vector2( uv.x, uv.y ) );
vh.AddVert( new Vector3( v.x, v.w ), color32, new Vector2( uv.x, uv.w ) );
vh.AddVert( new Vector3( v.z, v.w ), color32, new Vector2( uv.z, uv.w ) );
vh.AddVert( new Vector3( v.z, v.y ), color32, new Vector2( uv.z, uv.y ) );
vh.AddTriangle( 0, 1, 2 );
vh.AddTriangle( 2, 3, 0 );
}
else
{
Vector4 spritePadding = DataUtility.GetPadding( sprite );
Vector2 spriteRectSize = sprite.rect.size;
Vector2 spriteNonPaddingSize = spriteRectSize - new Vector2( spritePadding.x + spritePadding.z, spritePadding.y + spritePadding.w );
Vector2 spritePivot = sprite.pivot;
Vector2 spriteNormalizedPivot = new Vector2( ( spritePivot.x - spritePadding.x ) / spriteNonPaddingSize.x, ( spritePivot.y - spritePadding.y ) / spriteNonPaddingSize.y );
Vector2 spriteBoundSize = Vector2.Scale( sprite.bounds.size, new Vector2( spriteNonPaddingSize.x / spriteRectSize.x, spriteNonPaddingSize.y / spriteRectSize.y ) );
Vector2 drawingSize = new Vector2( v.z - v.x, v.w - v.y );
Vector2 drawOffset = Vector2.Scale( rectTransform.pivot - spriteNormalizedPivot, drawingSize );
Vector2[] vertices = sprite.vertices;
Vector2[] uvs = sprite.uv;
ushort[] triangles = sprite.triangles;
for( int i = 0; i < vertices.Length; ++i )
vh.AddVert( new Vector3( ( vertices[i].x / spriteBoundSize.x ) * drawingSize.x - drawOffset.x, ( vertices[i].y / spriteBoundSize.y ) * drawingSize.y - drawOffset.y ), color32, new Vector2( uvs[i].x, uvs[i].y ) );
for( int i = 0; i < triangles.Length; i += 3 )
vh.AddTriangle( triangles[i + 0], triangles[i + 1], triangles[i + 2] );
}
}
public override void SetNativeSize()
{
if( sprite != null )
{
Vector4 padding = DataUtility.GetPadding( sprite );
Vector2 size = sprite.rect.size;
size -= new Vector2( padding.x + padding.z, padding.y + padding.w );
float w = size.x / pixelsPerUnit;
float h = size.y / pixelsPerUnit;
rectTransform.anchorMax = rectTransform.anchorMin;
rectTransform.sizeDelta = new Vector2( w, h );
SetAllDirty();
}
}
int ILayoutElement.layoutPriority {
get {
return 0; } }
float ILayoutElement.minWidth {
get {
return 0f; } }
float ILayoutElement.minHeight {
get {
return 0f; } }
float ILayoutElement.flexibleWidth {
get {
return -1; } }
float ILayoutElement.flexibleHeight {
get {
return -1; } }
float ILayoutElement.preferredWidth {
get {
return sprite ? ( sprite.rect.size.x / pixelsPerUnit ) : 0f; } }
float ILayoutElement.preferredHeight {
get {
return sprite ? ( sprite.rect.size.y / pixelsPerUnit ) : 0f; } }
void ILayoutElement.CalculateLayoutInputHorizontal() {
}
void ILayoutElement.CalculateLayoutInputVertical() {
}
// Whether this is being tracked for Atlas Binding
private bool m_Tracked = false;
#if UNITY_2017_4 || UNITY_2018_2_OR_NEWER
private static List<PaddingIgnoringImage> m_TrackedTexturelessImages = new List<PaddingIgnoringImage>();
private static bool s_Initialized;
#endif
private void TrackImage()
{
if( sprite != null && sprite.texture == null )
{
#if UNITY_2017_4 || UNITY_2018_2_OR_NEWER
if( !s_Initialized )
{
SpriteAtlasManager.atlasRegistered += RebuildImage;
s_Initialized = true;
}
m_TrackedTexturelessImages.Add( this );
#endif
m_Tracked = true;
}
}
private void UnTrackImage()
{
#if UNITY_2017_4 || UNITY_2018_2_OR_NEWER
m_TrackedTexturelessImages.Remove( this );
#endif
m_Tracked = false;
}
#if UNITY_2017_4 || UNITY_2018_2_OR_NEWER
private static void RebuildImage( SpriteAtlas spriteAtlas )
{
for( int i = m_TrackedTexturelessImages.Count - 1; i >= 0; i-- )
{
PaddingIgnoringImage image = m_TrackedTexturelessImages[i];
if( spriteAtlas.CanBindTo( image.sprite ) )
{
image.SetAllDirty();
m_TrackedTexturelessImages.RemoveAt( i );
}
}
}
#endif
}