I have a text box with a query the the user can load and change or leave alone. I have a test database that the user sends this to with a Development Test button. The results are displayed in another forms text box in XML.
Is there a way to check if the user changed anything in the text box since the development button was pushed? I have another button called production where, if the results returned to the user are correct the user can save this query to a production database.
What I want to prevent is a user loading a correctly worded query, test it, the results are good, and then the user changes something, either on accident or on purpose where this query will no longer work, and submitting it to production. At which point there will be errors and things will have to be found and changed. I would like a little message box that comes up and says: "The text box has been changed since you tested it are you sure you want to submit this to production". Now they can still submit it but at least they are warned..
Presume at some point a button is pushed or some action happens.
1) When you load the box, you could hold the original value in a variable
2) When the action occurs, you could re-query the same query and make another round-trip to retrieve the original value
3) Then compare the original value with current
if (textBox.Text == myOriginalValue)
{
}
else
{
}
You can subscribe to the TextChanged event, and update your field then.
textbox.TextChanged += (sender, e) => { textValue = textbox.Text; };
set a dirty flag in a Tag property and check it.
//Set 1 in the Tag property after loading data
private void LoadData()
{
textBox1.Text = myValue;
textBox1.Tag = 0;
}
//Set 0 in the Tag property on TextChange
private void textBox1_TextChange(object sender, EventArgs)
{
((TextBox)sender).Tag = 1;
}
//Check if Tag != 0 then do your stuff.
private void button1_click(object sender, EventArgs e)
{
if (textBox1.Tag != null && Convert.ToInt32(textBox1.Tag) != 0)
{
MessageBox.Show("The text box has been changed since you tested it are you sure you want to submit this to production", "Value Has Changed");
}
}
Related
I have a DataGridView with several columns of TextBoxes. I need to capture the event where they are done entering data, and are exiting the box (via Tab, Enter, Mouse click elsewhere, etc)
I have searched SO and Google, and it seems like you have to build an event from scratch. I've tried multiple variations on what I have found since I can't seems to find one that fits with my particular needs.
I've been at this for longer than I care to admit and I need help.
Here is what I have...
// Select DataGridView EditingControlShowing Event
Private void gridData_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e) {
e.Control.TextChanged += new EventHandler(textBox_TextChanged);
Control cntObject = e.Control;
cntObject.TextChanged += textBox_TextChanged;
}
// TextBox TextChanged Event
Private void textBox_TextChanged(object sender, EventArgs e) {
// Checks to see if the AddlQty field was altered
if (gridData.Columns[e.ColumnIndex].Name == "AddlQty") {
// Validate Entry
if (e.Text is Not numeric) {
MessageBox.Show("Entry Not Valid, Only Numeric Values Accepted");
} else {
CalcFinalQty(e.RowIndex);
}
}
}
For the record, the code does NOT work, the validation is quasi code and I'm getting an error in the function heading. The important part for me is the
if (gridData.Columns[e.ColumnIndex].Name == "AddlQty"){ }
I just need help getting to that point.
I'm using web forms
Right now my code runs when I leave the text box and the text has changed. I am running into issues. If I change the text but hit a button instead of enter, it resets via code. I need to be able to change the text and click a button which wont yet do anything, or change the text and hit enter which will trigger code.
thanks for the help
This is text changed event for the text box with notations of what im needing to do. really what I think I need is an event for clicking enter, not changing text
protected void txtboxPlate_TextChanged(object sender, EventArgs e)
{
if (txtboxPlate.Text == "plate number")
{
//will check database for "plate number" and do stuff on enter.
}
else
{
resetforms();// on enter
}
else
{
the text has changed by user, but has clicked a button and needs nothing to happen because of this text change
}
}
You need to implement a method for the KeyDown event of your textbox.
private void txtboxPlate_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.Enter) {
//Code
}
}
Keydown is a client-side event, as far as I know you're more than likely going to have to use JavaScript/Jquery.
Refer to the following link:
Textbox Keydown Event
I would of used a comment but... rep issues :/
edit:
To anyone that hasn't realised yet, the question changed to webforms not winforms
Alternative:
Use a button.
You could place a button next to the textfield, it's simple and not a lot of work goes into it. You can set the TabIndex of the textbox to 1 and the TabIndex of the button to 2 so when you hit TAB it will focus the textbox and if pressed again it will focus the button. You could also look into adding the button to the textbox for design purposes.
edit: You also need to think about post back, when you hit a button the page get's post back meaning values are lost, to persist the data within the field you would have to use view state, session variables or a hidden field. For simplicity I'd set the value of the text box to a hidden field and then simply re-apply the value on page_load. If the value needs to persist across multiple postbacks/accessed from other pages use session variables.
So as a code example:
Remove the Text_changed event entirely.
protected void btnDoStuff(object sender, EventArgs e)
{
if(txtPlateNumber.Text == "Plate Number")
{
//Do stuff
}
else
{
//Do other stuff
}
}
-
If you notice the value disappearing after the post back do something like:
protected void btnDoStuff(object sender, EventArgs e)
{
if(txtPlateNumber.Text == "Plate Number")
{
//Do stuff
myHiddenField.Value == txtPlateNumber.Text;
}
else
{
//Do other stuff
}
}
then reset the value on page_load.
If this is winform and you still want to use textchanged you can try catching your code first for example:
protected void txtboxPlate_TextChanged(object sender, EventArgs e)
{
//Catching code
if (txtboxPlate.Text != "")
{
if (txtboxPlate.Text == "plate number")
{
//will check database for "plate number" and do stuff on enter.
}
else
{
resetforms();// on enter
}
}
else
{
the text has changed by user, but has clicked a button and needs nothing to happen because of this text change
}
cause what textchanged is doing is unless txtboxPlate.Text equels "plate number" it will always do the else statement. Correct me if i'm wrong though but i had the same problem before which almost made me go insane.
Or try above 1 upvote code:
protected void txtboxPlate_TextChanged(object sender, EventArgs e)
{
//Event only happens if you press enter
if (e.KeyCode == Keys.Enter)
{
if (txtboxPlate.Text == "plate number")
{
//will check database for "plate number" and do stuff on enter.
}
else
{
resetforms();// on enter
}
}
else
{
the text has changed by user, but has clicked a button and needs nothing to happen because of this text change
}
}
I am trying to follow the MSDN example code for the Control.Validating Event and to apply it to a bindingNavigator item instead of the textbox as in the example.
The code provided for the textbox validation event is shown below.
private void textBox1_Validating(object sender,
System.ComponentModel.CancelEventArgs e)
{
string errorMsg;
if(!ValidEmailAddress(textBox1.Text, out errorMsg))
{
// Cancel the event and select the text to be corrected by the user.
e.Cancel = true;
textBox1.Select(0, textBox1.Text.Length);
// Set the ErrorProvider error with the text to display.
this.errorProvider1.SetError(textBox1, errorMsg);
}
}
I too intend on validating texboxes however I have several and have already written the validation methods for them which handle the error messages. I would like these methods to be tested when the user selects an item (Arrow buttons / Save button / Add button) on the bindingNavidator.
I therefore have the code below to attempt this,
private void myBindingNavigator_Validating(object sender, CancelEventArgs e)
{
if (!IsPostCodeValid())
{
PostCodeTextBox.Focus();
e.Cancel = true;
}
}
I have the ItemClicked event for the bindingNavigator set to bindingNavigator.Focus() with the hope of initiating the Validating event. (myBindingNavigator.CausesValidation = true; has been declared on formLoad). However I feel this is where an infinite loop of focusing the Navigation bar follows? I have stepped through and no code is executed once it has locked on to the Navigation bar it simply won't let the user interact with the rest of the form to change and correct the error after the navigation bar has been locked onto.
I can provide any extra information required and test any suggestions to discover what is going on.
Thanks
When you work with BindingNavigator and you have put your controls in details mode on the form, to ensure save only valid data, you should write validation rules for your controls and also you should handle your binding navigator items yourself.
This way you even don't need to set AutoValidate Property of your form to annoying EnablePreventFocusChange and you can set it to be the friendly EnableAllowFocusChange and because you can't navigate or save anything when there is validation errors, then you can be sure only valid data will save in database.
To do so, follow these steps:
Step 1
Handle Validating event of child controls and set e.cancel = true when the value is not valid.
private void nameTextBox_Validating(object sender, CancelEventArgs e)
{
//Put validation logic here
if (this.nameTextBox.Text.Length < 10)
{
e.Cancel = true;
this.errorProvider1.SetError(this.nameTextBox, "Some Error");
}
else
{
this.errorProvider1.SetError(this.nameTextBox, "");
}
}
Step 2
Go to BindingNavigator properties, and set MoveFirstItem, MovePreviousItem, MoveNextItem, MoveLastItem, AddNewItem, DeleteItem properties To (none). Also from designer click on the text box that shows record number, it is bindingNavigatorPositionItem, and then set its ReadOnly property to true.
Step 3
For all buttons, including navigation buttons, add button, delete button, save button and other custom buttons, handle Click event and call ValidateChildren method of the container of your text boxes and check if ValidateChildren() doesn't return true, exit the method, else do the task that the method should do, for example:
private void toolStripButton1_Click(object sender, EventArgs e)
{
if (!this.ValidateChildren())
return;
//Put the logic for this button here
//MoveFirstItem: `this.myBindingSource.MoveFirst();`
//MovePreviousItem: `this.myBindingSource.MovePrevious();`
//MoveNextItem: `this.myBindingSource.MoveNext();`
//MoveLastItem: `this.myBindingSource.MoveLast();`
//AddNewItem: `this.myBindingSource.AddNew();`
//DeleteItem: `this.myBindingSource.RemoveCurrent();`
}
Let's say we have a Win32 form with a Save toolbar button and some sontrols like a CheckBox are on the form, now we write a one line code for onchange event of checkbox to enable/disable the Save button. Let's say checkbox is selected at first, Save button disabled, now de-select the checkbox, Save button becomes enabled...now select the checkbox again Save button is still enabled...Same for a TextBox for example. Let's say its text is "Hi"...change it to "Hi Bye" , Save is enabled...change it BACK to "Hi" as it was, Save remains enabled...
Is there a model we can use to prevent these wrong enabling/disabling of save button?
You need to write some IF - ELSE code in the CheckedChanged event of the Checkbox. Check what is the current state by inspecting the Checked proeprty of the control (checkbox) ,If yes set the Enabled proeprty of the Button to true, else false.
private void checkBox2_CheckedChanged(object sender, EventArgs e)
{
if (checkBox2.Checked)
button1.Enabled = true;
else
button1.Enabled = false;
}
Assuming checkBox2 is the name of the Checkbox and button1 is the name of the Save button.
You can use the same IF ELSE logic for other controls also. To Set the Value of the Textbox, Use the Text property
TextBox1.Text="I am gonna try something now"l
EDIT : As comecme suggested, If you only want to enable/disable button based on the checbox, It can be done in one line instead of the IF else block like this
button1.Enabled=checkBox2.Checked
You could store the last saved state, and compare the current state to it whenever it changes, to see if they're identical. If so, disable the button.
If these comparisons are expensive, you could make this more efficient, by calculating a hash value over all of the fields that need to be saved, and only doing the proper comparison if the hash of the last saved state matches the hash of the current state.
I prefer to put all my control state checking and setting into a single method:
private void UpdateControls()
{
saveButton.Enabled = checkBox1.Checked;
otherButton.Visible = checkBox2.Checked && textBox.Text.Length > 0;
}
private void checkBox1_CheckedChanged(object sender, EventArgs e)
{
UpdateControls();
}
private void checkBox2_CheckedChanged(object sender, EventArgs e)
{
UpdateControls();
}
private void textBox_TextChanged(object sender, EventArgs e)
{
UpdateControls();
}
This means you just have one place in which to check and set the state, and makes it much easier to understand what is going on, especially when you have complex forms. I also prefer boolean expressions rather than if statements when assigning boolean variables, because it caters for both true and false without having to write a separate else statement (which may be forgotten).
I don't get where you're going with your checkbox, but I would use a Boolean variable:
private Boolean _canSave = false;
private Boolean CanSave
{
get { return _canSave; }
set
{
_canSave = value;
MenuSave.Enabled = value;
}
}
public void MenuSave_Click()
{
Save();
}
private void Save()
{
// do your thing
CanSave = false;
}
public void TextBox_TextChanged()
{
CanSave = true;
}
This won't account for disabling the saving menu when you revert the text back to its original. If you want that, you'll have to store the text in the Save() method in a private variable, and compare that to the current text on every TextBox_TextChanged() to determine whether a change compared to the original (i.e. since last save) has occurred.
I am trying to make the save button visible when text is entered into the text box by using the following code:
if (tbName.TextModified == true)
{
btnCTimetablesOk.Visible = true;
}
else
{
btnCTimetablesOk.Visible = false;
}
but it gives error at tbname.textmodified
is there any other way to visible the button when we enter the text in text box
this is error i am getting "the event textbox.textmodified can only appear on the left hand side of += or -="
Try using the textbox's Enter and Leave events to show/hide your button:
private void textBox1_Enter(object sender, System.EventArgs e)
{
btnCTimetablesOk.Visible = true;
}
private void textBox1_Leave(object sender, System.EventArgs e)
{
btnCTimetablesOk.Visible = false;
}
Then modify your textbox to use these new methods.
If I'm reading your text correctly, you want the save button to be visible when the textbox has text in it and invisible when the text box is blank. If that's the case, you can use the Leave event (which occurs when the textbox loses focus) and a simple if statement:
private void textBox1_Leave(object sender, System.EventArgs e)
{
if(textBox1.Text != "")
btnCTimetablesOk.Visible = true;
else
btnCTimetablesOk.Visible = false;
}
You can also put this conditional block in any other methods kicked off by events that change the text of the box.
Also, you might want to consider using Enabled instead of Visible, it'll leave the button on the form but will gray out the text and clicking will do nothing.
I'm going to take a stab in the dark here and assume that the button is related to the textbox and you probably want someone to be able to type something in the textbox then click the button. You probably don't want the user to have to type something, then tab out or click somewhere else to make the button visible then click the button.
tbName_TextChanged(object sender, EventArgs e)
{
btnCTimetablesOk.Visible = !String.IsNullOrEmpty(tbName.Text)
}
Btw you're getting that error because TextModified isn't a boolean property, it's an event, like TextChanged or Leave or Enter. You can assign an event handler to it but you can't just check it like that.
As an aside I personally hate systems hungarian for winforms controls. I'd much rather have a timetablesOkButton than a btnCTimeablesOK button. That way if you also have a timetablesNameTextBox you can see at a glance that the button and the textbox match. Of course it may not be up to you.