iOS:释放 NSString 对象，从 sqlite 数据库读取数据

Question

我有一个应用程序，它从 sqlite 数据库读取数据，然后在每次单击按钮后在按钮中显示内容。

 NSString *data;    
 query = [NSString stringWithFormat:@"SELECT * FROM %@ WHERE ID=%d",TABLENAME,tempIndex];
 sqlite3_prepare_v2(contactDB,[query UTF8String],-1,&statement,NULL);
 sqlite3_step(statement);
 data = [[NSString alloc] initWithUTF8String:(const char *)sqlite3_column_text(statement, 2)];
 sqlite3_finalize(statement);
 [myButton setTitle:data forState:UIControlStateNormal];
 [data release];

但是，数据从未显示在按钮中，并且出现错误:

Error loading /System/Library/Extensions/AppleHDA.kext/Contents/PlugIns/AppleHDAHALPlugIn.bundle/Contents/MacOS/AppleHDAHALPlugIn:  dlopen(/System/Library/Extensions/AppleHDA.kext/Contents/PlugIns/AppleHDAHALPlugIn.bundle/Contents/MacOS/AppleHDAHALPlugIn, 262): Symbol not found: _CFXMLNodeGetInfoPtr

如果我不释放数据，应用程序运行正常

Answer 1

这是非常奇怪的行为，我很想弄清楚它的真相。但现在，自动释放您的数据字符串。

 data = [[[NSString alloc] initWithUTF8String:(const char *)sqlite3_column_text(statement, 2)] autorelease]