如何在IOS中使用9-patch圖像？

Question

我想在我的IOS應用程序中使用9補丁圖像。可能嗎？

Answer 1

調查UIImage的方法resizableImageWithCapInsets:(UIEdgeInsets)capInsets。

Answer 2

最有可能的結果是 https://github.com/andylanddev/Tortuga22-NinePatch 9補丁庫已經使用波紋管方法 resizableImageWithCapInsets：（UIEdgeInsets）鑲石

Answer 3

你可以試試這個簡單的實現： https://github.com/shiami/SWNinePatchImageFactory

的概念是很簡單的描述如下：

該技術只是將9修補程序PNG圖像轉換爲iOS兼容，可調整大小的UIImage對象。 請參閱UIImage的方法resizableImageWithCapInsets：（UIEdgeInsets）insets以獲取更多信息。 所以它只支持在水平和垂直兩側伸展一段補丁標記。

+ (UIImage*)createResizableImageFromNinePatchImage:(UIImage*)ninePatchImage 
{ 
    NSArray* rgbaImage = [self getRGBAsFromImage:ninePatchImage atX:0 andY:0 count:ninePatchImage.size.width * ninePatchImage.size.height]; 
    NSArray* topBarRgba = [rgbaImage subarrayWithRange:NSMakeRange(1, ninePatchImage.size.width - 2)]; 
    NSMutableArray* leftBarRgba = [NSMutableArray arrayWithCapacity:0]; 
    int count = [rgbaImage count]; 
    for (int i = 0; i < count; i += ninePatchImage.size.width) { 
     [leftBarRgba addObject:rgbaImage[i]]; 
    } 

    int top = -1, left = -1, bottom = -1, right = -1; 
    count = [topBarRgba count]; 
    for (int i = 0; i <= count - 1; i++) { 
     NSArray* aColor = topBarRgba[i]; 
     if ([aColor[3] floatValue] == 1) { 
      left = i; 
      break; 
     } 
    } 
    NSAssert(left != -1, @"The 9-patch PNG format is not correct."); 
    for (int i = count - 1; i >= 0; i--) { 
     NSArray* aColor = topBarRgba[i]; 
     if ([aColor[3] floatValue] == 1) { 
      right = i; 
      break; 
     } 
    } 
    NSAssert(right != -1, @"The 9-patch PNG format is not correct."); 
    for (int i = left + 1; i <= right - 1; i++) { 
     NSArray* aColor = topBarRgba[i]; 
     if ([aColor[3] floatValue] < 1) { 
      NSAssert(NO, @"The 9-patch PNG format is not support."); 
     } 
    } 
    count = [leftBarRgba count]; 
    for (int i = 0; i <= count - 1; i++) { 
     NSArray* aColor = leftBarRgba[i]; 
     if ([aColor[3] floatValue] == 1) { 
      top = i; 
      break; 
     } 
    } 
    NSAssert(top != -1, @"The 9-patch PNG format is not correct."); 
    for (int i = count - 1; i >= 0; i--) { 
     NSArray* aColor = leftBarRgba[i]; 
     if ([aColor[3] floatValue] == 1) { 
      bottom = i; 
      break; 
     } 
    } 
    NSAssert(bottom != -1, @"The 9-patch PNG format is not correct."); 
    for (int i = top + 1; i <= bottom - 1; i++) { 
     NSArray* aColor = leftBarRgba[i]; 
     if ([aColor[3] floatValue] == 0) { 
      NSAssert(NO, @"The 9-patch PNG format is not support."); 
     } 
    } 

    UIImage* cropImage = [ninePatchImage crop:CGRectMake(1, 1, ninePatchImage.size.width - 2, ninePatchImage.size.height - 2)]; 

    return [cropImage resizableImageWithCapInsets:UIEdgeInsetsMake(top, left, bottom, right)]; 
} 

SWNinePatchImageView還提供了Nib或Storyboard的用法。 您可以檢查回購中的示例項目。