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Thread: data is not appending to the file

  1. #1
    Join Date
    Nov 2007
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    Qt products
    Qt4
    Platforms
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    Unhappy data is not appending to the file

    Hello all,
    i had a problem to access the file operation, when i tried to write something to the file from my GUI(designer file) then it erasing all the data exist in the file and writing only string which i entered in the LineEdit but i want to be append it to the file.
    Here is my code


    Qt Code:
    1. #include<QtCore>
    2. #include<QtGui>
    3. #include"ui_dialog1.h"
    4. #include <stdio.h>
    5.  
    6.  
    7. class synopsys : public QDialog,public Ui::dialog1
    8. {
    9. Q_OBJECT
    10.  
    11. public:
    12. synopsys()
    13. {
    14. setupUi(this);
    15. connect(pushButton1, SIGNAL(clicked()), this , SLOT(save()));
    16. connect(pushButton2, SIGNAL(clicked()), this , SLOT(close()));
    17.  
    18. }
    19.  
    20. public slots:
    21.  
    22. void save()
    23. {
    24. Qt::CheckState state1,state2,state3,state4;
    25.  
    26. state1 = checkBox1->checkState();
    27. state2 = checkBox2->checkState();
    28. state3 = checkBox3->checkState();
    29. state4 = checkBox4->checkState();
    30.  
    31. if(state1 == Qt::Checked)
    32. {
    33. fileName = "/home/window1/synopsys_startup.txt";
    34. QFile file(fileName);
    35. QString str = lineEdit1->text();
    36.  
    37. const char *ch = str.toLatin1();
    38. file.open(QIODevice::WriteOnly);
    39. file.write(ch, qstrlen(ch));
    40. file.close();
    41.  
    42. }
    43.  
    44.  
    45.  
    46.  
    47. if(state2 == Qt::Checked)
    48. {
    49.  
    50. fileName = "/home/window1/synopsys_startup.txt";
    51. QFile file(fileName);
    52. QString str = lineEdit2->text();
    53.  
    54. const char *ch = str.toLatin1();
    55. file.open(QIODevice::WriteOnly);
    56. file.write(ch, qstrlen(ch));
    57. file.close();
    58.  
    59.  
    60. }
    61.  
    62.  
    63. if(state3 == Qt::Checked)
    64. {
    65.  
    66. fileName = "/home/window1/synopsys_startup.txt";
    67. QFile file(fileName);
    68. QString str = lineEdit3->text();
    69.  
    70. const char *ch = str.toLatin1();
    71.  
    72. file.open(QIODevice::WriteOnly);
    73. file.write(ch, qstrlen(ch));
    74. file.close();
    75.  
    76.  
    77.  
    78. }
    79.  
    80.  
    81. if(state4 == Qt::Checked)
    82. {
    83.  
    84. fileName = "/home/window1/synopsys_startup.txt";
    85. QFile file(fileName);
    86. QString str = lineEdit4->text();
    87.  
    88. const char *ch = str.toLatin1();
    89. file.open(QIODevice::WriteOnly);
    90. file.write(ch, qstrlen(ch));
    91. file.close();
    92.  
    93.  
    94.  
    95. }
    96.  
    97.  
    98. }
    99. private:
    100. QString fileName;
    101.  
    102. };
    103.  
    104. int main(int argc, char *argv[])
    105. {
    106.  
    107. QApplication app(argc,argv);
    108.  
    109. synopsys *startup = new synopsys;
    110. startup->show();
    111.  
    112. return app.exec();
    113. }
    114.  
    115. #include "main.moc"
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    any help or suggestion will be much appreciated
    Last edited by wysota; 3rd April 2008 at 16:58. Reason: missing [code] tags

  2. #2
    Join Date
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    Warsaw, Poland
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    Default Re: data is not appending to the file

    You have to open the file in proper mode. "WriteOnly" overwrites the current content of the file. You have to use Append.

  3. The following user says thank you to wysota for this useful post:

    sudheer (3rd April 2008)

  4. #3
    Join Date
    Nov 2007
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    Qt products
    Qt4
    Platforms
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    Default Re: data is not appending to the file

    thanks i dint observe that

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