原文：iphone 输入/输出流异步读写数据

分类： iphone2012-05-30 14:50 2484人阅读 评论(1) 收藏 举报

iphoneattributesinterfacepathstreamfile

1、首先是往文件里写入数据

WriteFile.h

[cpp] view plaincopy

1. #import <Foundation/Foundation.h>
2. #import <UIKit/UIKit.h>
3. @class NoteDb;
4. @interface WriteFile : NSObject<NSStreamDelegate>{
5. //文件地址
6. NSString *parentDirectoryPath;
7. //输出流，写数据
8. NSOutputStream *asyncOutputStream;
9. //写数据的内容
10. NSData *outputData;
11. //位置及长度
12. NSRange outputRange;
13. //数据的来源
14. NoteDb *aNoteDb;
15. }
16. @property (nonatomic,retain) NSData *outputData;
17. @property (nonatomic,retain) NoteDb *aNoteDb;
18. //写数据
19. -(void)write;
20. @end

实现文件WriteFile.m

[cpp] view plaincopy

1. #import "WriteFile.h"
2. #import "NoteDb.h"
3. @implementation WriteFile
4. @synthesize outputData,aNoteDb;
5. -(id)init{
6. self=[super init];
7. if (!self) {
8. [self release];
9. return nil;
10. }
11. outputData=[[NSData alloc]init];
12. aNoteDb=[[NoteDb alloc]init];
13. return self;
14. }
15. -(void)write{
16. //NSLog(@"%@",self.aNoteDb);
17. //沙盒路径
18. NSArray *paths= NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
19. NSString *documentsDirectory = [paths objectAtIndex:0];
20. //文件名字是note.txt
21. NSString *path = [documentsDirectory stringByAppendingPathComponent:@"note.txt"];
22. [asyncOutputStream release];
23. parentDirectoryPath = path;
24. //数据源
25. NSData *tmpdata = [NSKeyedArchiver archivedDataWithRootObject:self.aNoteDb.noteList];
26. //self.outputData=[[NSData alloc]initWithData:tmpdata];
27. self.outputData=tmpdata;
28. //位置从哪开始
29. outputRange.location=0;
30. //创建文件
31. [[NSFileManager defaultManager] createFileAtPath:parentDirectoryPath
32. contents:nil attributes:nil];
33. //初始化输出流
34. asyncOutputStream = [[NSOutputStream alloc] initToFileAtPath: parentDirectoryPath append: NO];
35. //回调方法，
36. [asyncOutputStream setDelegate: self];
37. //异步处理，
38. [asyncOutputStream scheduleInRunLoop:[NSRunLoop currentRunLoop]  forMode:NSDefaultRunLoopMode];
39. //打开异步输出流
40. [asyncOutputStream open];
41. }
42. -(void)stream:(NSStream *)theStream handleEvent:(NSStreamEvent)streamEvent{
43. // NSLog(@"as");
44. NSOutputStream *outputStream = (NSOutputStream*) theStream;
45. BOOL shouldClose = NO;
46. switch (streamEvent)
47. {
48. case NSStreamEventHasSpaceAvailable://读事件
49. {
50. //缓冲区
51. uint8_t outputBuf [1];
52. //长度
53. outputRange.length = 1;
54. //把数据放到缓冲区中
55. [outputData getBytes:&outputBuf range:outputRange];
56. //把缓冲区中的东西放到输出流
57. [outputStream write: outputBuf maxLength: 1];
58. //判断data数据是否读完
59. if (++outputRange.location == [outputData length])
60. {
61. shouldClose = YES;
62. }
63. break;
64. }
65. case NSStreamEventErrorOccurred:
66. {
67. //出错的时候
68. NSError *error = [theStream streamError];
69. if (error != NULL)
70. {
71. UIAlertView *errorAlert = [[UIAlertView alloc]
72. initWithTitle: [error localizedDescription]
73. message: [error localizedFailureReason]
74. delegate:nil
75. cancelButtonTitle:@"OK"
76. otherButtonTitles:nil];
77. [errorAlert show];
78. [errorAlert release];
79. }
80. shouldClose = YES;
81. break;
82. }
83. case NSStreamEventEndEncountered:
84. shouldClose = YES;
85. }
86. if (shouldClose)
87. {
88. //当出错或者写完数据，把线程移除
89. [outputStream removeFromRunLoop: [NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
90. //最后关掉输出流
91. [theStream close];
92. }
93. }
94. -(void)dealloc{
95. [outputData release];
96. [aNoteDb release];
97. [super dealloc];
98. }
99. @end

2、其次是从文件里读出数据

ReadFile.h

[cpp] view plaincopy

1. #import <Foundation/Foundation.h>
2. @class NoteDb;
3. @interface ReadFile : NSObject<NSStreamDelegate>{
4. //路径
5. NSString *parentDirectoryPath;
6. //异步输出流
7. NSInputStream *asyncInputStream;
8. //读出来的数据
9. NSMutableData *resultData;
10. //返回去的数据
11. NoteDb *aNoteDb;
12. }
13. @property(nonatomic,retain)NoteDb *aNoteDb;
14. @property (nonatomic, retain) NSMutableData *resultData;
15. //开始读数据
16. -(void)read;
17. //读出来的数据追加到resultData上
18. - (void)appendData:(NSData*)_data;
19. //
20. - (void)dataAtNoteDB;
21. //返回去的数据
22. - (NoteDb*)getNoteDb;
23. @end

实现文件ReadFile.m

[cpp] view plaincopy

1. #import "ReadFile.h"
2. #import "NoteDb.h"
3. #import "NoteList.h"
4. #import "WriteFile.h"
5. @implementation ReadFile
6. @synthesize aNoteDb,resultData;
7. -(id)init{
8. self=[super init];
9. //aNoteDb=[[NoteDb alloc]init];
10. resultData=[[NSMutableData alloc]init];
11. return self;
12. }
13. -(void)read{
14. //沙盒路径
15. NSArray *paths= NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
16. NSString *documentsDirectory = [paths objectAtIndex:0];
17. //文件名
18. NSString *path = [documentsDirectory stringByAppendingPathComponent:@"note.txt"];
19. /*
20. if(![[NSFileManager defaultManager]fileExistsAtPath:path]){
21. //如果不存在，就新建
22. WriteFile *file=[[WriteFile alloc]init];
23. [file write];
24. [file release];
25. }else{
26. NSLog(@"有note.txt文件");
27. }
28. */
29. [asyncInputStream release];
30. parentDirectoryPath = path;
31. //异步输入流初始化，并把赋于地址
32. asyncInputStream =
33. [[NSInputStream alloc] initWithFileAtPath: parentDirectoryPath];
34. //设置代理（回调方法、委托）
35. [asyncInputStream setDelegate: self];
36. //设置线程，添加线程，创建线程：Runloop顾名思义就是一个不停的循环，不断的去check输入
37. [asyncInputStream scheduleInRunLoop:[NSRunLoop currentRunLoop]
38. forMode:NSDefaultRunLoopMode];
39. //打开线程
40. [asyncInputStream open];
41. }
42. //追加数据
43. - (void)appendData:(NSData*)_data{
44. [resultData appendData:_data];
45. }
46. //回调方法，不停的执行
47. -(void)stream:(NSStream *)theStream handleEvent:(NSStreamEvent)streamEvent{
48. BOOL shouldClose = NO;
49. NSInputStream *inputStream = (NSInputStream*) theStream;
50. //NSLog(@"as");
51. switch (streamEvent)
52. {
53. case NSStreamEventHasBytesAvailable:
54. {
55. //读数据
56. //读取的字节长度
57. NSInteger maxLength = 128;
58. //缓冲区
59. uint8_t readBuffer [maxLength];
60. //从输出流中读取数据，读到缓冲区中
61. NSInteger bytesRead = [inputStream read: readBuffer
62. maxLength:maxLength];
63. //如果长度大于0就追加数据
64. if (bytesRead > 0)
65. {
66. //把缓冲区中的数据读成data数据
67. NSData *bufferData = [[NSData alloc]
68. initWithBytesNoCopy:readBuffer
69. length:bytesRead
70. freeWhenDone:NO];
71. //追加数据
72. [self appendData:bufferData];
73. //release掉data
74. [bufferData release];
75. }
76. break;
77. }
78. case NSStreamEventErrorOccurred:
79. {
80. //读的时候出错了
81. NSError *error = [theStream streamError];
82. if (error != NULL)
83. {
84. UIAlertView *errorAlert = [[UIAlertView alloc]
85. initWithTitle: [error localizedDescription]
86. message: [error localizedFailureReason]
87. delegate:nil
88. cancelButtonTitle:@"OK"
89. otherButtonTitles:nil];
90. [errorAlert show];
91. [errorAlert release];
92. }
93. shouldClose = YES;
94. break;
95. }
96. case NSStreamEventEndEncountered:
97. {
98. shouldClose = YES;
99. //数据读完就返回数据
100. [self dataAtNoteDB];
101. [theStream close];
102. }break;
103. }
104. if (shouldClose)
105. {
106. //当文件读完或者是读到出错时，把线程移除
107. [inputStream removeFromRunLoop: [NSRunLoop currentRunLoop]
108. forMode:NSDefaultRunLoopMode];
109. //并关闭流
110. [theStream close];
111. }
112. }
113. -(void) dataAtNoteDB{
114. aNoteDb=nil;
115. aNoteDb=[[NoteDb alloc]init];
116. aNoteDb.noteList = [NSKeyedUnarchiver unarchiveObjectWithData:resultData];
117. //NSLog(@"%@",aNoteDb);
118. /*
119. for (id tmp in  aNoteDb.noteList.noteArray)
120. {
121. NSLog(@"tmp = %@",tmp);
122. }
123. */
124. }
125. - (NoteDb*)getNoteDb{
126. return self.aNoteDb;
127. }
128. -(void)dealloc{
129. [aNoteDb release];
130. [resultData release];
131. [super dealloc];
132. }
133. @end