UITextField实现PlaceHolder

@interface
ViewController () <UITextViewDelegate>

{

UITextView *_textView1;

UILabel *_label1;

}

@end

@implementation ViewController

- (void)viewDidLoad {

[super
viewDidLoad];

//首先定义UITextView

_textView1 = [[UITextView
alloc] init];

_textView1.font = [UIFont
systemFontOfSize:14];

_textView1.frame =CGRectMake(10,
30, 200,
300);

_textView1.autoresizingMask =
UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;

_textView1.backgroundColor = [UIColor
whiteColor];

[self.view
addSubview:_textView1];

_textView1.hidden =
NO;

_textView1.delegate =
self;

//其次在UITextView上面覆盖个UILable,UILable设置为全局变量。

_label1 = [[UILabel
alloc ] initWithFrame:CGRectMake(10,
30,
40, 30)];

_label1.text =
@"请填写审批意见...";

_label1.enabled =
NO;//lable必须设置为不可用

_label1.backgroundColor = [UIColor
clearColor];

[self.view
addSubview:_label1];

}

#pragma mark - 实现UITextView的代理

-(void)textViewDidChange:(UITextView *)textView

{

_textView1.text = textView.text;

if (textView.text.length ==
0)

{

_label1.text =
@"请填写审批意见...";

}else

{

_label1.text =
@"";

}

}