binding a windows datagrid to masterdetail data

... Binding a Windows DataGrid to Master-Detail Data Problem You need to bind both a parent table and child table within a DataSet to a DataGrid so that the child data is displayed when the parent ... data, navigation between related tables as well as formatting and editing capabilities. If a DataGrid is bound to a DataSet containing related tables, and navigation is enabled for the DataGrid, ... The DataGrid control can display a single DataTable or a DataSet containing a set of DataTable objects with a hierarchical relationship between them. The DataGrid provides a user interface...

Ngày tải lên: 24/10/2013, 11:15

... set to the DataSource. The MappingName of each DataGridColumnStyle object must be associated with the name of a DataColumn to synchronize the DataGrid display column with the data column. An ... duplicate mapping names are used. The DataGridTextBoxColumn class inherits from the abstract DataGridColumnStyle class. It defines the attributes, display format, and behavior of cells in a DataGrid ... for the DataGrid. Once defined, the Add( ) method of the DataGridTableStyles object is used to add the custom column styles to the DataGrid. The MappingName property of the DataGridTableStyle...

Ngày tải lên: 20/10/2013, 12:15

... hassles trying to track the data table directly. dtFromGrid = CType(dgTableData.DataSource, DataTable) ' Commands necessary to actually post back to server. modaLookupData.Update(dtFromGrid) ... ByVal e As System.EventArgs) Handles lstLookupTables.SelectedIndexChanged Dim dtData As New DataTable() Try ' Update the data adapter and data table to reflect the new data, ... the modaLookupData data adapter, and it is used to update the data table. The Update method of modaLookupData is executed, followed by the AcceptChanges method of the dtFromGrid data table....

Ngày tải lên: 14/12/2013, 20:16

Ngày tải lên: 24/12/2013, 01:17

Ngày tải lên: 24/12/2013, 01:17

... System .Data; using System .Data. SqlClient; private DataSet ds; private SqlDataAdapter da; private BindingManagerBase bm; // . . . private void DisplayDatabaseImageForm_Load(object ... that are bound to the same data source so that they display information from the object within the data source, such as a row in a DataTable. The BindingContext class is used to instantiate ... need to display an image from a database in a Windows Forms control. Solution Read the image into a byte array and load it directly into a PictureBox control with a MemoryStream. The sample...

Ngày tải lên: 28/10/2013, 18:15

... ADO.NET automatically stores database connections in a pool. Connection pooling offers a great performance improvement because you don't have to wait for a brand new connection to the database ... System .Data; using System .Data. SqlClient; class ConnectionPooling { public static void Main() { // create a SqlConnection object to connect to the database, // setting max pool size to ... database to be established when there's a suitable connection already available. When you close a connection, that connection isn't actually closed; instead, your connection is marked as...

Ngày tải lên: 07/11/2013, 10:15

... to update changes made back to the database. The DataAdapter is used to fill a DataTable in a new DataSet with the schema and data from TBL0709. The text boxes displaying the data for the fields ... Binding a Group of Radio Buttons in a Windows Form Problem You need to bind a field in a database to a radio button and update the database with the radio button selected. Solution Use a ... RadioButton controls to a data source. Binding a single radio button to a data source isn't a particularly common requirement—nor is it particularly useful—since radio buttons are normally...

Ngày tải lên: 07/11/2013, 13:15

... class. The following example defines a method named StateChangeHandler to handle the StateChange event. You'll notice that the second parameter to this method is a StateChangeEventArgs ... request to the database; two examples of states are open and closed. You use the Connection object's State property to get the current state of the connection to the database. The State property ... SqlConnection("server=localhost;database=Northwind;uid=sa;pwd=sa"); // monitor the StateChange event using the StateChangeHandler() method mySqlConnection.StateChange += new StateChangeEventHandler(StateChangeHandler);...

Ngày tải lên: 14/12/2013, 13:15

... pixels may appear many times, and in an audio file, a string of audio samples may also appear repeatedly. A dictionary-based method maintains a dictionary that contains bits and pieces of the data. As ... next example is even more convincing (and only somewhat contrived): alfeastmaneasilyyells A| AAAAAAAAAA AAAAAH . The encoder creates the token (1,9 ,A) , matching the first nine copies of A in ... the fact that parts of data tend to appear several times in a given data file. Thus, a text file may contain several occurrences of a word, a phrase, or a syllable. In an image file, the same string...

Ngày tải lên: 14/12/2013, 15:15

... the telephone) was given to Alexander Graham Bell. Bain’s fax machine transmitter scanned a flat, electrically conductive metal surface with a stylus mounted on a pendulum that was powered by an electromagnet. ... encoder transmits the compressed data, as it is being generated, over a network. In such a case, a code with large variance causes the encoder to generate bits at a rate that varies all the time. ... bits have to be transmitted at a constant rate, the encoder has to use a buffer. Bits of the compressed data are entered into the buffer as they are being generated and are moved out of it at a constant...

Ngày tải lên: 14/12/2013, 15:15

... case of many grayscales) or three components (in the case of a color image). A continuous-tone image is normally a natural image (natural as opposed to artificial) and is obtained by taking a photograph ... searching for the farthest array element to the left of a 9 that has a count smaller than that of a 9 . This search can be a straight linear search if the array is short enough, or a binary search ... out that there is a simple data structure that allows for both easy search and update. This structure is a balanced binary tree housed in an array. (A balanced binary tree is a complete binary...

Ngày tải lên: 14/12/2013, 15:15

... called the Haar measure, which allows an analog of Lebesgue integrals to be defined on locally compact topological groups. Mathematical lore has it that John von Neumann tried to discourage Haar ... scientists, artists, or writers whose names are inextricably associated with Canada. Similarly, no Canadian plays, stories, or traditional legends are as well-known as the Shakespeare plays, Grimm ... of a worldwide digital component video standard. Y is defined to have a range of 16 to 235; Cb and Cr are defined to have a range of 16 to 240, with 128 equal to zero. There are several YCbCr sampling...

Ngày tải lên: 14/12/2013, 15:15

... came. —Tom Clancy, Clear and Present Danger Chapter Summary Images are an important type of digital multimedia data. Images are popular, they are easy to create (by a digital camera, scanning a document, ... the matrix approach to the Haar transform to introduce the reader to the idea of filter banks. We show how the Haar transform can be interpreted as a bank of two filters, a lowpass and a highpass. ... (5.11) Instead of calculating averages and differences, all we have to do is construct matri- ces A 1 , A 2 ,andA 3 , multiply them to get W = A 1 A 2 A 3 , and apply W to all the columns of an image...

Ngày tải lên: 14/12/2013, 15:15

... is called digitally sampled analog data (DSAD). (See also Scalar Quantization.) Voronoi Diagrams. Imagine a petri dish ready for growing bacteria. Four bacteria of different types are simultaneously ... In practice, vector quantization is commonly used to compress data that has been digitized from an analog source, such as sampled sound and scanned images (drawings or photographs). Such data is ... in the bottom-right subband (HH) indicate a diagonal artifact located above the main diagonal. It is also easy to see that subband LL is a low-resolution version of the original image. 12 16...

Ngày tải lên: 14/12/2013, 15:15

... (1: a) and (2: b). The encoder outputs 1 (a) , 2 (b), 3 (ab), 5 (aba), 4 (ba), 7 (bab), 6 (abab), 9 (ababa), 8 (baba), and adds the new entries (3: ab), (4: ba), (5: aba), (6: abab), (7: bab), ... initialized to the fourth a. Continuing this process is straightforward. The result is that strings aa, aaa, aaaa, are added to the dictionary as entries 256, 257, 258, , and the output is 97 (a) , ... the Haar Wavelet Transform,” Spel- man College Science and Mathematics Journal, 1(1):22–31, April. Also available at URL http://www.spelman.edu/~colm/wav.ps. (It has been claimed that any smart 15-year-old...

Ngày tải lên: 14/12/2013, 15:15

... new TableAdapter class. Click Finish to close the Wizard. A TableAdapter class called DataTable1TableAdapter, and a corresponding DataTable class called DataTable1, appear in the DataSet Designer ... A DataTable and TableAdapter object are added to the DataSet Designer window, and the TableAdapter Configuration Wizard appears. 5. In the Choose Your Data Connection page of the TableAdapter ... A TableAdapter can generate two methods for populating a DataTable object with the rows retrieved from the database: the Fill method which expects an existing DataTable or DataSet as a parameter...

Ngày tải lên: 15/12/2013, 00:15

Ngày tải lên: 17/01/2014, 08:20

Ngày tải lên: 18/01/2014, 05:20