iOS實現逐幀動畫做loading視圖
本文實例為大傢分享瞭iOS實現逐幀動畫做loading視圖的具體代碼，供大傢參考，具體內容如下
我封裝瞭一個可復用的loading視圖組件，用於按照一定周期逐幀播放加載動畫。代碼如下：
.h文件
#import <UIKit/UIKit.h>
//加載狀態
typedef enum {
FZImageSequenceLoadingStatusStop = 1, // 停止
FZImageSequenceLoadingStatusLoading, // 加載中
FZImageSequenceLoadingStatusError //發生錯誤
} FZImageSequenceLoadingStatus;
@interface FZImageSequenceLoadingView : UIView {
UIImageView *_imageView;
UILabel *_lblMsg;
NSTimer *timer;
int currentImageIndex;
}
@property(strong) NSArray *imageArray; //動畫序列的圖片數組
@property(strong, nonatomic) UIImage *errorImage;
@property(nonatomic, strong) NSString *errorMsg;
@property(nonatomic, strong) NSString *loadingMsg; //提示文字
@property(nonatomic) CGRect imageFrame; //圖片的Frame
@property(nonatomic) CGRect msgFrame; //文字內容的Frame
@property(nonatomic) float timerInterval; //切換圖片的周期
/**
切換狀態
*/
- (void)switchToStatus:(FZImageSequenceLoadingStatus)status;
/**
通過圖片名字和數量設置圖片數組，如給定名字"name"、“.png”和數量4，則會去加載“name_1.png”到"name_4.png"的圖片
*/
- (void)setImageArrayByName:(NSString *)name andExtName:(NSString *)extName andCount:(int)count;
@end
.m文件
#import "FZImageSequenceLoadingView.h"
@implementation FZImageSequenceLoadingView
@synthesize errorImage;
@synthesize errorMsg;
@synthesize imageArray;
@synthesize loadingMsg;
@synthesize timerInterval;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
timerInterval = 1;
currentImageIndex = -1;
}
return self;
}
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect
{
// Drawing code
}
*/
- (void)setupSubviews {
// self.backgroundColor = [UIColor redColor];
if (self.imageArray && self.imageArray.count > 0) {
if (!_imageView) {
_imageView = [[UIImageView alloc] init];
[self addSubview:_imageView];
}
//讓圖片view為本view的頂部居中，大小為圖片數組中的第一張
UIImage *firstImg = [self.imageArray objectAtIndex:0];
_imageView.size = firstImg.size;
_imageView.top = 0;
_imageView.left = (self.size.width - _imageView.size.width) / 2;
}
if (self.loadingMsg) {
CGSize labelSize = [self.loadingMsg sizeWithFont:[UIFont systemFontOfSize:11]];
if (!_lblMsg) {
_lblMsg = [[UILabel alloc] initWithFrame:CGRectZero];
_lblMsg.textAlignment = NSTextAlignmentCenter;
[self addSubview:_lblMsg];
}
_lblMsg.font = [UIFont systemFontOfSize:11];
_lblMsg.size = labelSize;
_lblMsg.textColor = [UIColor darkGrayColor];
_lblMsg.backgroundColor = [UIColor clearColor];
_lblMsg.bottom = self.height;
_lblMsg.left = (self.width - _lblMsg.width) / 2;
}
}
- (void)switchToStatus:(FZImageSequenceLoadingStatus)status {
if (!_lblMsg || !_imageView) {
[self setupSubviews];
}
switch (status) {
case FZImageSequenceLoadingStatusError:
[self switchToError];
break;
case FZImageSequenceLoadingStatusLoading:
[self switchToLoading];
break;
case FZImageSequenceLoadingStatusStop:
[self switchToStop];
break;
}
}
- (void)switchToStop {
[timer invalidate];
timer = nil;
if (self.imageArray && self.imageArray.count > 0) {
_imageView.image = [self.imageArray objectAtIndex:0];
}
}
- (void)switchToError {
[timer invalidate];
timer = nil;
//如果有錯誤狀態的圖
if (self.errorImage) {
_imageView.image = self.errorImage;
//如果沒有就用第一張動畫圖
} else if (self.imageArray && self.imageArray.count > 0) {
_imageView.image = [self.imageArray objectAtIndex:0];
}
if (self.errorMsg) {
_lblMsg.text = self.errorMsg;
}
}
- (void)switchToLoading {
if (self.loadingMsg) {
_lblMsg.text = self.loadingMsg;
}
if (!timer) {
timer = [NSTimer scheduledTimerWithTimeInterval:self.timerInterval target:self selector:@selector(showNextImage) userInfo:nil repeats:YES];
}
}
- (void)showNextImage {
if (!imageArray || imageArray.count < 1) {
return;
}
currentImageIndex = (currentImageIndex + 1) % self.imageArray.count;
// 主線程執行：
dispatch_async(dispatch_get_main_queue(), ^{
_imageView.image = [imageArray objectAtIndex:currentImageIndex];
});
}
- (void)setImageArrayByName:(NSString *)name andExtName:(NSString *)extName andCount:(int)count {
NSAssert((name && extName && (count > 0)), @"圖片名字和數量錯誤");
NSMutableArray *imgs = [NSMutableArray arrayWithCapacity:count];
for (int i = 1; i <= count; i++) {
NSString *imgName = [NSString stringWithFormat:@"%@_%i%@", name, i, extName];
UIImage *image = [UIImage imageNamed:imgName];
NSLog(@"%@", image);
if (!image) {
continue;
}
[imgs addObject:image];
}
self.imageArray = imgs;
}
@end
使用示例，在uiwebview中使用如下：
初始化視圖：
//設置loading視圖
- (void)setupLoadingView {
if (!_loadingView) {
_loadingView = [[FZImageSequenceLoadingView alloc] initWithFrame:CGRectMake(0, 0, 170, 70)];
_loadingView.center = self.view.center;
[_loadingView setImageArrayByName:@"loading" andExtName:@".png" andCount:10];
_loadingView.loadingMsg = @"努力加載中，請稍候";
_loadingView.errorMsg = @"加載失敗";
_loadingView.timerInterval = 0.1;
_loadingView.hidden = YES;
[self.view addSubview:_loadingView];
}
}
在uiwebview的代理方法中切換狀態：
#pragma mark - webview delegate
- (void)webViewDidStartLoad:(UIWebView *)webView {
if (_loadingView.hidden) {
_loadingView.hidden = NO;
[_loadingView switchToStatus:FZImageSequenceLoadingStatusLoading];
}
}
- (void)webViewDidFinishLoad:(UIWebView *)webView {
if (!_loadingView.hidden) {
[_loadingView switchToStatus:FZImageSequenceLoadingStatusStop];
_loadingView.hidden = YES;
}
}
- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error {
NSLog(@"load page error:%@", [error description]);
if (!_loadingView.hidden) {
[_loadingView switchToStatus:FZImageSequenceLoadingStatusError];
}
}
目前該組件功能還不夠完善，但是能滿足目前我自己的需求，後續再繼續豐富。
以上就是本文的全部內容，希望對大傢的學習有所幫助，也希望大傢多多支持WalkonNet。