UIImage *image = [UIImage imageNamed:@"聊天后背景图"];
    
    // 设置端盖的值
    CGFloat top = 10;
    CGFloat left = 30;
    CGFloat bottom = 10;
    CGFloat right = 10;
    
    // 设置端盖的值
    UIEdgeInsets edgeInsets = UIEdgeInsetsMake(top, left, bottom, right);
    // 设置拉伸的模式
    UIImageResizingMode mode = UIImageResizingModeStretch;
    // 拉伸图片
    UIImage *newImage = [image resizableImageWithCapInsets:edgeInsets resizingMode:mode];
    self.testImageView.image  = newImage;
        self.imageViewOne.image = newImage;