实现 placeholder 详见： http://code4app.com/ios/CBTextView/523965516803fa4e61000001
自定义一个CBTextView.h (也可以从上面网址下载，然后直接看后面的调用即可)
#import <UIKit/UIKit.h>
@interface CBTextView : UIView
{
UIColor *defaultTextColor;
NSString *prevText;
}
@property (strong, nonatomic) UITextView *textView;
@property (strong, nonatomic) NSString *placeHolder;
@property (strong, nonatomic) UIColor *placeHolderColor;
@property (weak, nonatomic) id<UITextViewDelegate> aDelegate;
@end
CBTextView.m
#import "CBTextView.h"
#define SHOW_DEBUG_VIEW 0
#define RGBAlphaColor(r, g, b, a) \
[UIColor colorWithRed:(r/255.0)\
green:(g/255.0)\
blue:(b/255.0)\
alpha:(a)]
#define OpaqueRGBColor(r, g, b) RGBAlphaColor((r), (g), (b), 1.0)
@interface CBTextView () <UITextViewDelegate>
@end
@implementation CBTextView
- (id)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
if (self) {
[self setup];
}
return self;
}
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
[self setup];
}
return self;
}
- (void)setup
{
[self addSubview:self.textView];
self.placeHolderColor = OpaqueRGBColor(199, 200, 201);
self.textView.delegate = self;
#if SHOW_DEBUG_VIEW
self.textView.backgroundColor = DEBUG_VIEW_ITEM_COLOR;
self.backgroundColor = DEBUG_VIEW_CONTAINER_COLOR;
#endif
}
#pragma mark - Layout
- (void)setFrame:(CGRect)frame
{
[super setFrame:frame];
CGRect aFrame = CGRectZero;
aFrame.origin = self.bounds.origin;
aFrame.size = frame.size;
self.textView.frame = aFrame;
}
#pragma mark - Accessor
- (void)setPlaceHolder:(NSString *)placeHolder
{
_placeHolder = placeHolder;
self.textView.text = placeHolder;
}
- (void)setPlaceHolderColor:(UIColor *)placeHolderColor
{
_placeHolderColor = placeHolderColor;
self.textView.textColor = placeHolderColor;
}
- (void)setTextColor:(UIColor *)textColor
{
defaultTextColor = self.textView.textColor;
self.textView.textColor = textColor;
}
- (void)setADelegate:(id)aDelegate
{
_aDelegate = aDelegate;
}
- (UITextView *)textView
{
if (_textView == nil) {
_textView = [[UITextView alloc] init];
_textView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
}
return _textView;
}
#pragma mark - UITextViewDelegate
- (BOOL)textViewShouldBeginEditing:(UITextView *)textView
{
if ([self.aDelegate respondsToSelector:@selector(textViewShouldBeginEditing:)]) {
return [self.aDelegate textViewShouldBeginEditing:textView];
}
return YES;
}
- (BOOL)textViewShouldEndEditing:(UITextView *)textView
{
if ([self.aDelegate respondsToSelector:@selector(textViewShouldEndEditing:)]) {
return [self.aDelegate textViewShouldEndEditing:textView];
}
return YES;
}
- (void)textViewDidBeginEditing:(UITextView *)textView
{
self.textView.text = prevText;
self.textView.textColor = defaultTextColor;
if ([self.aDelegate respondsToSelector:@selector(textViewDidBeginEditing:)]) {
[self.aDelegate textViewDidBeginEditing:textView];
}
}
- (void)textViewDidEndEditing:(UITextView *)textView
{
prevText = self.textView.text;
if (!prevText || [prevText length]==0) {
self.textView.text = self.placeHolder;
self.textView.textColor = self.placeHolderColor;
}
if ([self.aDelegate respondsToSelector:@selector(textViewDidEndEditing:)]) {
[self.aDelegate textViewDidEndEditing:textView];
}
}
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
if ([self.aDelegate respondsToSelector:@selector(textView:shouldChangeTextInRange:replacementText:)]) {
return [self.aDelegate textView:textView shouldChangeTextInRange:range replacementText:text];
}
return YES;
}
- (void)textViewDidChange:(UITextView *)textView
{
if ([self.aDelegate respondsToSelector:@selector(textViewDidChange:)]) {
[self.aDelegate textViewDidChange:textView];
}
}
- (void)textViewDidChangeSelection:(UITextView *)textView
{
if ([self.aDelegate respondsToSelector:@selector(textViewDidChangeSelection:)]) {
[self.aDelegate textViewDidChangeSelection:textView];
}
}
#pragma mark - Actions
- (BOOL)resignFirstResponder
{
return [self.textView resignFirstResponder];
}
@end
开始调用：
#import "CBTextView.h"
@property(strong,nonatomic)CBTextView *textView;
CBTextView *textView1=[[CBTextView alloc]initWithFrame:CGRectMake(5, 5, 220, 80)];
textView1.backgroundColor=[UIColor clearColor];
self.textView=textView1;
_textView.placeHolder = @"这软件做得不错,你们接受定制开发吗?";
_textView.placeHolderColor = [UIColor grayColor];
self.textView.aDelegate=self;
[self.view addSubview:textView1];
//隐藏键盘，实现UITextViewDelegate
-(BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString*)text
{
if ([text isEqualToString:@"\n"]) {
[self.textView resignFirstResponder];
return NO;
}
return YES;
}