c# 删除处理!

[perfect_love]

private void buttonOK5_Click(object sender, EventArgs e) //删除
{
string str, All ;
StreamReader stream1 = new StreamReader(@"f:\Test.txt", true);
string str1 = this.textBName.Text;
while (str1.Length < 8)
str1 = str1 + " ";
if (str1.Length > 8)
str1 = str1.Substring(0, 8);
while ((str = stream1.ReadLine()) != null)
{
//str = stream1.ReadLine();
if (str.Substring(0, 8) != str1)
{
All += str;
MessageBox.Show(All); //测试中数据进入了All; }
else if (str.Substring(0, 8) == str1)
MessageBox.Show("成功！");
}
stream1.Close();
StreamWriter stream2 = new StreamWriter(@"f:\Test.txt");
stream2.WriteLine(All);
MessageBox.Show(All); //可是在这里All就是空了!
}

不知道是什么原因!
有谁能帮忙改改啊!
谢谢!!!!!!!!!!!

[zzyhuian06142]

StreamReader里面不是保存写入的吧

[zzyhuian06142]

看错了,呵呵

[zhchg6666]

在最后执行stream1.Close(); 试下

[zzyhuian06142]

建议设置断点调试一下,看ALL在哪边为空了

[soaringbird]

string str, All = "";

[yuxianye1]

stream2.WriteLine(All); //这里有么？
MessageBox.Show(All);

[xhan2000]

是不是这里
stream2.WriteLine(All);

[hopewoo]

string str, All ;
            All = "";
            StreamReader stream1 = new StreamReader(@"f:\Test.txt", true); 
            string str1 = "gfdgfdgfdgdf";        
            while (str1.Length < 8) 
                str1 = str1 + " "; 
            if (str1.Length > 8) 
                str1 = str1.Substring(0, 8); 
            while ((str = stream1.ReadLine()) != null) 
            { 
                //str = stream1.ReadLine(); 
                if (str.Substring(0, 8) != str1)
                {
                    All += str;
                    MessageBox.Show(All);
                }//测试中数据进入了All;                } 
                else
                {
                    if (str.Substring(0, 8) == str1)
                        MessageBox.Show("成功！");
                }
            } 
            stream1.Close(); 
            StreamWriter stream2 = new StreamWriter(@"f:\Test.txt"); 
            stream2.WriteLine(All); 
            MessageBox.Show(All);  //可是在这里All就是空了!      

如果test.txt里面有内容的话,这段代码是没问题的.关键看你
while ((str = stream1.ReadLine()) != null)
进去了没.

[soaringbird]

最后写入后没有stream2.Close();所以数据就丢了。
所以在第一次运行时正常，第二次all就是空的了

[zzyhuian06142]

string str="", All="" ;
StreamReader stream1 = new StreamReader(@"c:\CSDN.txt", true);
string str1 = "KevinTex";
// while (str1.Length < 8)
// str1 = str1 + " ";
// if (str1.Length > 8)
// str1 = str1.Substring(0, 8);
while ((str = stream1.ReadLine()) != null)
{
//str = stream1.ReadLine();
if (str.Substring(0, 8) != str1)
{
All += str;
MessageBox.Show(All);
}//测试中数据进入了All;
else if (str.Substring(0, 8) == str1)
MessageBox.Show("成功！");
}
stream1.Close();
StreamWriter stream2 = new StreamWriter(@"c:\CSDN.txt");
stream2.WriteLine(All);
stream2.Close();
MessageBox.Show(All); //可是在这里All就是空了!

[zzyhuian06142]

这个是测试过的
像soaringbird说的,一定要stream2.Close();

[yuxianye1]

string str, All="" ; 
            StreamReader stream1 = new StreamReader(@"f:\Test.txt", true); 
            string str1 = "11111111";        
            while (str1.Length < 8) 
                str1 = str1 + " "; 
            if (str1.Length > 8) 
                str1 = str1.Substring(0, 8); 

            while ((str = stream1.ReadLine()) != null) 
            { 
                //str = stream1.ReadLine(); 
                if (str.Substring(0, 8) != str1) 
                { 
                    All += str; 
                    MessageBox.Show(All);    //测试中数据进入了All;                
                } 
                else if (str.Substring(0, 8) == str1) 
                    MessageBox.Show("成功！"); 
            } 
            stream1.Close(); 

            StreamWriter stream2 = new StreamWriter(@"f:\Test.txt"); 
            stream2.WriteLine(All); 
            MessageBox.Show(All);  //可是在这里All就是空了!     
            stream2.Close();

经过测试可以删除

[perfect_love]

在最后加 stream2.Close(); All里是不为空了,不过不管我有多少的数据,就第一条记录回被保存!
?????

[chinaicm]

LZ,你那程序我测试了,如果
if (str.Substring(0, 8) != str1)
{
All += str;
MessageBox.Show(All);
}//测试中数据进入了All;
程序能进入这里,最后哪个MessageBox.Show(All); 不可能显示不出来

你是流没有关闭,导致数据丢失了.

[soaringbird]

[Quote=引用 13 楼 perfect_love 的回复:]
在最后加  stream2.Close();  All里是不为空了,不过不管我有多少的数据,就第一条记录回被保存!
?????
[/Quote]

你的程序把所有的内容连接成一行了

[perfect_love]

就是哈!谢谢13楼哈!

[我姓区不姓区]

没有关闭流