菜鸟教程小白 发表于 2022-12-12 10:21:23

iOS : Could not convert const char to NSString object


                                            <p><p>我需要将 const char 类型数据转换为 NSString 对象类型,因为 sqlite 数据库返回 char * 类型数据。为此,我使用了 NSString 类方法 stringWithUTF8strin 但它是
返回 NULL。它获取 sqlite 文本类型数据。</p>

<p>这是我的代码:</p>

<pre><code>-(void)getAllData:(const char *)sqlQuery
{
name=[init];

department=[init];
image=[init];
testimonial=[init];
@try
{

NSArray *pathArray=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *final_phone_path=[stringByAppendingPathComponent:@&#34;amarinf5_excel.sqlite&#34;];
NSLog(@&#34;%@&#34;,final_phone_path);

NSFileManager *myFileManager=;

if(!)
{
    NSLog(@&#34;file doesnot exist&#34;);
}
if( sqlite3_open(, &amp;dataBAse)!=SQLITE_OK)
{
   NSLog(@&#34;could not be able to open the file&#34;);
}
const char *sql=sqlQuery;
sqlite3_stmt *statement;
if(sqlite3_prepare_v2(dataBAse, sql, -1, &amp;statement, nil)!=SQLITE_OK)
{
    NSLog(@&#34;Error message fail to prepare statement %s&#34;,sqlite3_errmsg(dataBAse));
}


while(sqlite3_step(statement)==SQLITE_ROW)
{
    const char *name1=(char *)sqlite3_column_text(statement, 0);
    const char *deprtment1=(char *)sqlite3_column_text(statement, 1);
    const char *image1= (char *)sqlite3_column_text(statement, 2);
    **const char *testimonial1=(char *)sqlite3_column_text(statement, 3);
    NSLog(@&#34;%@&#34;,);**
    NSLog(@&#34;%s&#34;,testimonial1);
    NSLog(@&#34;%@&#34;,);
    ];
    ];
    ];

    //];
    NSLog(@&#34;%@&#34;,);
}
if (sqlite3_finalize(statement) != SQLITE_OK)
{
    NSLog(@&#34;Failed to finalize data statement, normally error handling here.&#34;);
}
if (sqlite3_close(dataBAse) != SQLITE_OK)
{
    NSLog(@&#34;Failed to close database, normally error handling here.&#34;);
}
}
@catch (NSException *exception) {
NSLog(@&#34;An exception occurred: %@&#34;, );

}
@finally {

}

}
</code></pre></p>
                                    <br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
                                            <p><p>当我使用 stringWithFormat 方法找到不同的 NSString 解决方案时,下面是我的代码</p>

<pre><code> while(sqlite3_step(statement1)==SQLITE_ROW)
{
    const char *name1=(char *)sqlite3_column_text(statement1, 0);
    const char *deprtment1=(char *)sqlite3_column_text(statement1, 1);
    const char *image1= (char *)sqlite3_column_text(statement1, 2);
    const char *testimonial1=(char *)sqlite3_column_text(statement1, 3);


    ];
    ];
    ];
    ];

}
</code></pre></p>
                                   
                                                <p style="font-size: 20px;">关于iOS : Could not convert const char to NSString object,我们在Stack Overflow上找到一个类似的问题:
                                                        <a href="https://stackoverflow.com/questions/24077734/" rel="noreferrer noopener nofollow" style="color: red;">
                                                                https://stackoverflow.com/questions/24077734/
                                                        </a>
                                                </p>
                                       
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