关于slider设置setMinimumTrackImage与setMaximumTrackImage时

UIImage *yellow=[[UIImageimageNamed:@"y_yy"]stretchableImageWithLeftCapWidth:2topCapHeight:0];

UIImage *white=[[UIImageimageNamed:@"y_ww"]stretchableImageWithLeftCapWidth:2topCapHeight:0];

[leftSlider setMinimumTrackImage:yellowforState:UIControlStateNormal];

[leftSlider setMaximumTrackImage:whiteforState:UIControlStateNormal];

这样设置图片没显示的时候，可能是图片规格不对，图片yellow和white的高度决定slider的高度