UITextView默認文字提示

在UITextField中自帶placeholder屬性，可以用於提示輸入框信息。但是UITextView並不具備此功能
介紹兩種方法來實現：
第一種：
初始化UITextView
//首先定義UITextView
UITextView *textView = [[UITextView alloc] init];
textView.font = [UIFont systemFontOfSize:14];
textView.frame =CGRectMake(10, 0, cell.contentView.bounds.size.width-20, side);
textView.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
textView.backgroundColor = [UIColor whiteColor];
[cell.contentView addSubview:textView];
textView.hidden = NO;
textView.delegate = self;
//其次在UITextView上面覆蓋個UILable,UILable設置為全局變量。
uilabel.frame =CGRectMake(17, 8, cell.contentView.bounds.size.width - side+10, 20);
uilabel.text = @"請填寫審批意見...";
uilabel.enabled = NO;//lable必須設置為不可用
uilabel.backgroundColor = [UIColor clearColor];
[cell.contentView addSubview:uilabel];
實現UITextView的代理
-(void)textViewDidChange:(UITextView *)textView
{
self.examineText = textView.text;
if (textView.text.length == 0) {
uilabel.text = @"請填寫審批意見...";
}else{
uilabel.text = @"";
}
}