Asp. NET Basics (ii)

The RadioButton control is rendered as <input type= "Radio"/&gt on the client, and as with the server-side controls, it can be grouped by groupname attributes.

The button control is rendered as <input type= "Submit" on the client/>

The LinkButton control renders as <a href= "Javascript:__dopostback" on the client/>

The ImageButton control is a button that can be set ImageUrl, which renders <input type= "image" on the client/>
The same point: you can set the OnClientClick property to "return confirm (' OK to delete? ')";

The Panel control renders a div on the client, and if its GroupingText property is set, it is rendered as a <fieldset><legend> setting </legend></fieldset The effect of GroupBox.

The hyperlink control renders the <a/> tag on the client.
You can set the property navigateurl= "" and target= "", if the ImageUrl property is set, it will be rendered as <a href= "" ><image/></a>.

The FileUpload control is rendered as <input type= "file" on the client.
The code that generally uploads the file is written like this
if (Fileupload1.hasfile ())
{
String uploadpath = Server.MapPath ("~/upload/");
Fileupload1.saveas (Uploadpath + fileupload1.filename);
}

Overall, the controls are divided into three types:
1) HTML control
2) ASP. NET Server Control
3) HTML control with runat= "Server"

validation controls
1) Requirefieldvalidator: Required fields, can be used to service the non-null check, Common properties are: errormessage, ControlToValidate, InitialValue. You can write the if (this) on the server side of the validation. Isvalide) {...}
2) RangeValidator: Determines whether the value is between the given maximum value (MaximumValue) and the minimum (MinimumValue), the data types that can be compared are string, int, currency.
3) CompareValidator: The relationship that is used to compare two values satisfies the required or specified type of data. Comparison operators are: <,>,=,!=. Common properties: ValueToCompare: Compare with which value, ControlToCompare: which control to compare.
4) RegularExpressionValidator: A regular expression used to verify data satisfaction. Common Properties: ValidationExpression: Defines a regular expression.
5) CustomValidator: Custom validation for special cases.
6) Note: (1) Almost all validation controls have to be verified on the client and server side.
(2) Grouping validation controls: ValidationGroup
(3) Whether to trigger the checksum event: Causevalidation:false, which indicates that no validation events are triggered
(4) Modify whether the validation control occupies a bit: display is set to dynamic or static.

Data binding
1) Example: <itemtemplate><% #Eval ("Id")%></ItemTemplate >
2) Repeater data controls are used to iterate through the data, and of course, we can also write with a foreach statement.
3) Other templates for repeater controls
(1) <AlternatingItemTemplate> set the different styles of interlaced, that is, the style of even lines.
(2) <HeadTemplate> and <FootTemplate> head end of the template, respectively, displayed in front and back of the data, such as to prevent <table></table> or <ul> </ul> and so on.
(3) <seperatortemplate> a separator between two items of data.

Only the path of the picture is stored in the database, Resolveclienturl ("~/images/+ url");

Controls placed in the <ItemTemplate> template cannot be manipulated directly in the background C # code, and the control must first be found through the ID, such as: E. Item.findcontrol ("txtname");

Repeater controls are typically used only to display data, and the ListView control is more convenient for adding and removing adaptation operations.

Eval () is a one-way binding that reads data from the database; bind () is a two-way binding that allows you to read the values in the database to the page, and also to upload the user's values to the database.

Considerations for the ListView control:
(1) Auto-generated style to be refined into CSS style, do not make inline;
(2) <ItemTemplate> There is generally no need to use the <asp:Label> control to display read-only data, direct output can be.
(3) A service-side control with ID Itemplaceholder must be in <LayoutTemplate>. Change the table header automatically generated English field to Chinese, the useless ID to delete, no need to show it.

It should be noted in the ItemDataBound event that:
(1) Determine the type of data row E.item.itemtype = = Listviewitemtype.datarow
(2) Obtain the corresponding Rowview listviewdataitem Lvdataitem = (listviewdataitem) e.item; DataRowView Rowview = (DataRowView) Lvdataitem.dataitem;
(3) When using FindControl should pay attention to alternatingitemtemplate problems.

The difference between a ListView and a GridView
(1) GridView can only be rendered as table
(2) The ListView can be rendered as a table or as a <ul><li>

DropDownList controls bind SelectedValue properties, such as: Selectedvalue= "<% #Eval (' txtname ')%>"

If the page front-end does not involve the deletion and modification of interactive information such as the pure Display page, you can disable ViewState, there are two ways:
(1) Overall page disable ViewState: At the top <page> label Nega enabelviewstate= "false"
(2) Disable viewstate for the specified control: add enabelviewstate= "false" to the control's properties

Website Performance Tuning
(1) Caching cache is the first means of website performance tuning;
(2) Indexing index is the first means of database performance tuning;

How to set the page cache: in the header area <page> set <%@ OutputCache duration= "" "Varybyparam=" None "(this is variable, can be set to parameters: Id;num;age, etc.)% >

How to set the data cache, set properties for ObjectDataSource,
(1) enablecaching= "True"
(2) cacheduration= "20"

Written in the back: Mr. Lu Xun has a saying, "Where is genius?" I used to work and study for people who drank coffee! "Very much agree, Qinnengbuzhuo is good training." All right, let's get here today!

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