Lecture 7 Dialog Controls MDI Parent/Child Interaction

1. Lecture 7 Dialog Controls MDI Parent/Child Interaction

2. Multiple Document Interface Text Editor

3. FontDialog An instance of the FontDialog class has fields and methods for displaying and selecting font types, sizes and styles. In an MDI application we can direct actions onto the ActiveMdiChild from the MdiParent The widgets on a form are called Controls and can be accessed by their index value. For example the richtextbox of New-File-0 is this.ActiveMdiChild.Controls[0] privatevoidfontToolStripMenuItem_Click(object sender, EventArgs e) { if (this.ActiveMdiChild != null) { FontDialog fontdlg = newFontDialog(); fontdlg.Font = this.ActiveMdiChild.Controls[0].Font; fontdlg.ShowDialog(); this.ActiveMdiChild.Controls[0].Font = fontdlg.Font; } }

4. ColorDialog The ColorDialog can be used to select a standard color or to create a custom color that can be applied to any object that has a Color property. privatevoid fontColorToolStripMenuItem_Click(object sender, EventArgs e) { if (this.ActiveMdiChild != null) { ColorDialog cdlg = newColorDialog(); cdlg.Color = this.ActiveMdiChild.Controls[0].ForeColor; cdlg.ShowDialog(); this.ActiveMdiChild.Controls[0].ForeColor = cdlg.Color; } }

5. ColorDialog privatevoid backgroundColorToolStripMenuItem_Click(object sender, EventArgs e) { if (this.ActiveMdiChild != null) { ColorDialog cdlg = newColorDialog(); cdlg.Color = this.ActiveMdiChild.Controls[0].BackColor; cdlg.ShowDialog(); this.ActiveMdiChild.Controls[0].BackColor = cdlg.Color; } }

6. makeNewMdiChild( ) A new frmChild Form is created each time this method is called. A class-level variable, newindex is used to create a unique name for each new Form New-File-#. privatevoid makeNewMdiChild() { MDIEditor.frmChild child = new MDIEditor.frmChild(this); child.Show(); this.ActiveMdiChild.Text = "New-File-" + Convert.ToString(newindex); newindex += 1; } privatevoid newToolStripMenuItem_Click(object sender, EventArgs e) { makeNewMdiChild(); } privatevoid openFile() { OpenFileDialog openFileDlg = newOpenFileDialog(); openFileDlg.Filter = "Text files (*.txt)|*.txt|All files (*.*)|*.*"; openFileDlg.FilterIndex = 1; if (openFileDlg.ShowDialog() == DialogResult.OK) { makeNewMdiChild(); this.ActiveMdiChild.Text = openFileDlg.FileName; StreamReader r = newStreamReader(openFileDlg.FileName); this.ActiveMdiChild.Controls[0].Text = r.ReadToEnd(); r.Close(); } } privatevoid openToolStripMenuItem_Click(object sender, EventArgs e) { openFile(); } creates a new instance of frmChild and gives it a unique name. called when File-> New is clicked... also called when File->Open is clicked and filename returned from openFileDlg returns DialogResult.OK. in this case the name of the frmChild is changed to openFileDlg.FileName.

7. Arrange - Cascade, Horizontal, Vertical Cascade TileHorizontal TileVertical >3 forms 3 forms privatevoid cascadeToolStripMenuItem_Click(object sender, EventArgs e) { this.LayoutMdi(MdiLayout.Cascade); } privatevoid horizontalToolStripMenuItem_Click(object sender, EventArgs e) { this.LayoutMdi(MdiLayout.TileHorizontal); } privatevoid verticalToolStripMenuItem_Click(object sender, EventArgs e) { this.LayoutMdi(MdiLayout.TileVertical); } when there are more than three child forms, the Arrange operations do not produce results implied by their names.

8. Save As - SaveFileDialog privatevoid saveFileAs() { SaveFileDialog saveFileDlg = newSaveFileDialog(); saveFileDlg.Filter = "Text files (*.txt)|*.txt|All files (*.*)|*.*"; saveFileDlg.FilterIndex = 1; if (saveFileDlg.ShowDialog() == DialogResult.OK) { StreamWriter w = newStreamWriter(saveFileDlg.OpenFile()); w.Write(this.ActiveMdiChild.Controls[0].Text); w.Close(); this.ActiveMdiChild.Text = saveFileDlg.FileName; } } privatevoid saveAsToolStripMenuItem_Click(object sender, EventArgs e) { if (this.ActiveMdiChild != null) saveFileAs(); else MessageBox.Show("Nothing to Save"); }

9. Save - SaveFileDialog privatevoid saveFile() { SaveFileDialog saveFileDlg = newSaveFileDialog(); saveFileDlg.Filter = "Text files (*.txt)|*.txt|All files (*.*)|*.*"; saveFileDlg.FilterIndex = 1; saveFileDlg.FileName = this.ActiveMdiChild.Text; StreamWriter w = newStreamWriter(saveFileDlg.OpenFile()); w.Write(this.ActiveMdiChild.Controls[0].Text); w.Close(); } private voidsaveToolStripMenuItem_Click(object sender, EventArgs e) { if (this.ActiveMdiChild != null) { if (this.ActiveMdiChild.Text.Substring(0, 9) == "New-File-") saveFileAs(); else saveFile(); } else MessageBox.Show("Nothing to Save"); } privatevoid saveFileAs() { SaveFileDialog saveFileDlg = newSaveFileDialog(); saveFileDlg.Filter = "Text files (*.txt)|*.txt|All files (*.*)|*.*"; saveFileDlg.FilterIndex = 1; if (saveFileDlg.ShowDialog() == DialogResult.OK) { StreamWriter w = newStreamWriter(saveFileDlg.OpenFile()); w.Write(this.ActiveMdiChild.Controls[0].Text); w.Close(); this.ActiveMdiChild.Text = saveFileDlg.FileName; } }

10. class-level variables Paste Style publicColor fontColor = Color.Black; publicColor bkgColor = Color.White; publicFontfont; : privatevoid copyStyleToolStripMenuItem_Click(object sender, EventArgs e) { if (this.ActiveMdiChild != null) { fontColor = this.ActiveMdiChild.Controls[0].ForeColor; bkgColor = this.ActiveMdiChild.Controls[0].BackColor; font = this.ActiveMdiChild.Controls[0].Font; } } privatevoid pasteStyleToolStripMenuItem_Click(object sender, EventArgs e) { if (this.ActiveMdiChild != null) { this.ActiveMdiChild.Controls[0].ForeColor = fontColor; this.ActiveMdiChild.Controls[0].BackColor = bkgColor; if (font != null) this.ActiveMdiChild.Controls[0].Font = font; } } default Colors no default font specified Copy Style One of the most difficult tasks of applications development is the prediction and effective management of atypical User Behavior

11. Closing a Form We commonly refer to the action of removing a child form as Closing the Form. Actually what we are doing is disposing the form: Dispose( ) releases the object and prevents further use. Its memory resources are available for garbage collection, but are not necessarily returned immediately to the heap. Close( ) hides the object from view while leaving its properties, fields, methods, etc available. privatevoid closeToolStripMenuItem_Click(object sender, EventArgs e) { if(this.ActiveMdiChild != null) this.ActiveMdiChild.Dispose(); } privatevoid closeToolStripMenuItem_Click(object sender, EventArgs e) { if(this.ActiveMdiChild != null) this.ActiveMdiChild.Close(); }