TX Text Control Blog

Read only text frames in TX Text Control .NET

Blogged by Björn Meyer on March 22, 2007 and tagged with samples, .net.

Text frames are a very smart way to position text at a specific position in the document. They are commonly used for a recipient address details area on a letter or any other information that must be at a fixed position in a document.

TX Text Control offers properties to avoid the scaling and the movement of the frame:

Moveable

Sizeable

Sometimes, applications require that such text frames are not editable by the user. In this case, we can use the TextFrameActivated event to set a flag that indicates that a text frame is currently active.

void TX_TextFrameActivated(object sender, TXTextControl.TextFrameEventArgs e) { m_trapKeystrokes = true; }

On the KeyPress event, we can trap the keystrokes, if the mentioned flag has been set to true.

void m_tx_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e) { if (m_trapKeystrokes) e.Handled = true; }

The TextFrameDeactivated event is used to reset the global flag:

void m_tx_TextFrameDeactivated(object sender, TXTextControl.TextFrameEventArgs e) { m_trapKeystrokes = false; }

The following class is a sample how to inherit from the TextFrame class to create such protected text frames:

class ProtectedTextFrame : TXTextControl.TextFrame { private bool m_protected; private TXTextControl.TextControl m_tx; private bool m_trapKeystrokes = false; public ProtectedTextFrame(Size Size, bool Protected, TXTextControl.TextControl TX) : base(Size) { m_protected = Protected; m_tx = TX; if (m_protected) { m_tx.TextFrameActivated += new TXTextControl.TextFrameEventHandler(TX_TextFrameActivated); m_tx.TextFrameDeactivated += new TXTextControl.TextFrameEventHandler(m_tx_TextFrameDeactivated); m_tx.KeyPress += new System.Windows.Forms.KeyPressEventHandler(m_tx_KeyPress); } } void m_tx_KeyPress(object sender, System.Windows.Forms.KeyPressEventArgs e) { if (m_trapKeystrokes) e.Handled = true; } void m_tx_TextFrameDeactivated(object sender, TXTextControl.TextFrameEventArgs e) { m_trapKeystrokes = false; } void TX_TextFrameActivated(object sender, TXTextControl.TextFrameEventArgs e) { m_trapKeystrokes = true; } public bool Protected { get { return m_protected; } set { m_protected = value; } } }

This class can be instantiated like this:

ProtectedTextFrame newFrame = new ProtectedTextFrame(new Size(1000, 1000), true, textControl1); newFrame.Protected = true; textControl1.TextFrames.Add(newFrame, -1);

Feel free to contact me, if you want to discuss this approach or, if you have any questions.

 
 
User Contributed Note

User Contributed Note by anand kumar on November 3, 2008 at 7:43:16 AM CET

I created protected textframe by using your example code. when i click delete key inside the protected text frame and after i click the arrow key it throws insufficient memory (01--2-7) exception. Can u plz advice on this.