iOS 修改占位文字的字体大小和颜色

[cell.textFiledsetValue:[UIColorcolorWithRed:153.0/255green:153.0/255blue:153.0/255alpha:1.0]forKeyPath:@"_placeholderLabel.textColor"];

[cell.textFiledsetValue:[UIFontboldSystemFontOfSize:16]forKeyPath:@"_placeholderLabel.font"];