? ? ? ?以前一直對類似聊天氣泡背景圖片拉伸的設置糾結，不管如何設置UIEdgeInsets屬性都不能正常設置，今天對以下幾種情況進行了總結，如有需要的同學可進行參考：

項目地址：https://github.com/loverjiao0321/EdgeInsetsDemo

說明：

/**

1、UIEdgeInsets中的值都可以以像素為單位進行設置

2、測量凸起部分距離圖片邊緣值時，若有存在圓角部分，計算時最好將圓角部分出去，如: - (void)addDialogueLeft;方法中左側凸起部分為12像素，圖片額外含圓角部分8像素，則UIEdgeInsets中left和right值>= (12+8)計算

**/

/**

*添加左側凸起背景圖片

*/

leftDialogue

- (void)addDialogueLeft

{

UIImageView *bgImageView = [[UIImageView alloc] initWithFrame:CGRectMake(30, dialogueCount * (kDialogueSpace + kDialogueViewHeight), 315, kDialogueViewHeight)];

UIImage *image = [UIImage imageNamed:@"dialogueLeft"];

/*該圖片尺寸為354*97

**1、凸起部分右側距離圖片左側邊緣大概為20(包括圓角部分寬度)，因此UIEdgeInsets中left和right值>= 20即可.(此值若不合適繼續調大)

**2、不涉及上下距離，整體高度為97，因此UIEdgeInsets中top和bottom值<= 48即可.(此值若不合適繼續調小)

*/

UIEdgeInsets insets = UIEdgeInsetsMake(45, 20, 45, 20);

UIImage *insetImage = [image resizableImageWithCapInsets:insets];

bgImageView.image = insetImage;

[self.view addSubview:bgImageView];

dialogueCount++;

}

/**

*添加右側凸起背景圖片

*/

rightDialogue

- (void)addDialogueRight

{

UIImageView*bgImageView = [[UIImageViewalloc]initWithFrame:CGRectMake(30,dialogueCount* (kDialogueSpace+kDialogueViewHeight),315,kDialogueViewHeight)];

UIImage*image = [UIImageimageNamed:@"dialogueRight"];

/*該圖片尺寸為354*97

**1、凸起部分左側距離圖片右側邊緣大概為20(包括圓角部分寬度)，因此UIEdgeInsets中left和right值>= 20即可.(此值若不合適繼續調大)

**2、不涉及上下距離，整體高度為97，因此UIEdgeInsets中top和bottom值<= 48即可.(此值若不合適繼續調小)

*/

UIEdgeInsetsinsets =UIEdgeInsetsMake(45,20,45,20);

UIImage*insetImage = [imageresizableImageWithCapInsets:insets];

bgImageView.image= insetImage;

[self.viewaddSubview:bgImageView];

}

/**

*添加左上角凸起背景圖片

*/

topLeftDialogue

- (void)addDialogueTopLeft

{

UIImageView*bgImageView = [[UIImageViewalloc]initWithFrame:CGRectMake(30,dialogueCount* (kDialogueSpace+kDialogueViewHeight),315,kDialogueViewHeight)];

UIImage*image = [UIImageimageNamed:@"dialogueTopLeft"];

/*該圖片尺寸為343*106

**1、凸起部分右側距離圖片左側邊緣大概為27，因此UIEdgeInsets中left和right值>= 27即可.(此值若不合適繼續調大)

**2、凸起部分底部圖片高度（除去凸起高度）大概為98，因此UIEdgeInsets中top和bottom值<= 49即可.(此值若不合適繼續調小)

*/

UIEdgeInsetsinsets =UIEdgeInsetsMake(40,27,40,27);

UIImage*insetImage = [imageresizableImageWithCapInsets:insets];

bgImageView.image= insetImage;

[self.viewaddSubview:bgImageView];

}

/**

*添加左下角凸起背景圖片

*/

bottomLeftDialogue

- (void)addDialogueBottomLeft

{

UIImageView*bgImageView = [[UIImageViewalloc]initWithFrame:CGRectMake(30,dialogueCount* (kDialogueSpace+kDialogueViewHeight),315,kDialogueViewHeight)];

UIImage*image = [UIImageimageNamed:@"dialogueBottomLeft"];

/*該圖片尺寸為343*106

**1、凸起部分右側距離圖片左側邊緣大概為23，因此UIEdgeInsets中left和right值>= 23即可.(此值若不合適繼續調大)

**2、凸起部分底部圖片高度（除去凸起高度）大概為97，因此UIEdgeInsets中top和bottom值<= 48即可.(此值若不合適繼續調小)

*/

UIEdgeInsetsinsets =UIEdgeInsetsMake(40,23,40,23);

UIImage*insetImage = [imageresizableImageWithCapInsets:insets];

bgImageView.image= insetImage;

[self.viewaddSubview:bgImageView];

}

/**

*添加右上角凸起背景圖片

*/

topRightDialogue

- (void)addDialogueTopRight

{

UIImageView*bgImageView = [[UIImageViewalloc]initWithFrame:CGRectMake(30,dialogueCount* (kDialogueSpace+kDialogueViewHeight),315,kDialogueViewHeight)];

UIImage*image = [UIImageimageNamed:@"dialogueTopRight"];

/*該圖片尺寸為343*106

**1、凸起部分左側距離圖片右側邊緣大概為22，因此UIEdgeInsets中left和right值>= 22即可.(此值若不合適繼續調大)

**2、凸起部分底部圖片高度（除去凸起高度）大概為98，因此UIEdgeInsets中top和bottom值<= 49即可.(此值若不合適繼續調小)

*/

UIEdgeInsetsinsets =UIEdgeInsetsMake(40,22,40,22);

UIImage*insetImage = [imageresizableImageWithCapInsets:insets];

bgImageView.image= insetImage;

[self.viewaddSubview:bgImageView];

}

/**

*添加右下角凸起背景圖片

*/

bottomRightDialogue

- (void)addDialogueBottomRight

{

UIImageView*bgImageView = [[UIImageViewalloc]initWithFrame:CGRectMake(30,dialogueCount* (kDialogueSpace+kDialogueViewHeight),315,kDialogueViewHeight)];

UIImage*image = [UIImageimageNamed:@"dialogueBottomRight"];

/*該圖片尺寸為343*106

**1、凸起部分左側距離圖片右側邊緣大概為54，因此UIEdgeInsets中left和right值>= 54即可.(此值若不合適繼續調大)

**2、凸起部分底部圖片高度（除去凸起高度）大概為96，因此UIEdgeInsets中top和bottom值<= 48即可.(此值若不合適繼續調小)

*/

UIEdgeInsetsinsets =UIEdgeInsetsMake(45,54,45,54);

UIImage*insetImage = [imageresizableImageWithCapInsets:insets];

bgImageView.image= insetImage;

[self.viewaddSubview:bgImageView];

}