ASP.Net/Development/Color
Содержание
Color table (C#)
<source lang="csharp">
<%-- Pro ASP.NET Web Forms Techniques, Second Edition By Alex Homer ISBN: 1-59059-317-0 Published: Dec 2003 Publisher: Apress.ru --%>
<%@Page Language="C#" %> <%@Import Namespace="System.Drawing" %> <%@Import Namespace="System.Drawing.Imaging" %> <%@Import Namespace="System.Data" %> <script runat="server"> void Page_Load() {
Response.ContentType="image/gif"; String sCaption = "Chart caption"; DrawPieChart(GetDataSet(), 420, 250, sCaption);
} void DrawPieChart(DataSet dsData, int iWidth, int iHeight, String sCaption) {
Bitmap oBitMap = new Bitmap(iWidth, iHeight);
Graphics oGraphics = Graphics.FromImage(oBitMap);
Pen oPen = new Pen(Color.Black, 1);
SolidBrush oBrush = new SolidBrush(Color.White);
oGraphics.FillRectangle(oBrush, 0, 0, oBitMap.Width,
oBitMap.Height);
DrawText(oGraphics, 0, 0, oBitMap.Width, 20, sCaption,
FontStyle.Bold, 10, "", StringAlignment.Center, 0);
Color[] aColors = GetColorArray();
int iCaptionHeight = 30;
int iPieTopOffset = iCaptionHeight;
int iPieDiameter = oBitMap.Height - iCaptionHeight - 6;
if (iPieDiameter > (oBitMap.Width * 0.6)) {
iPieDiameter = (int)(oBitMap.Width * 0.6);
iPieTopOffset = ((oBitMap.Height - iPieDiameter) / 2) + iCaptionHeight;
}
Rectangle oRectPie = new Rectangle(0, iPieTopOffset,
iPieDiameter, iPieDiameter);
Rectangle oRectShadow = new Rectangle(5, iPieTopOffset + 5,
iPieDiameter, iPieDiameter);
// create color for shadows to objects
Color cShadow = Color.FromArgb(153, 153, 153);
// set brush color and draw circle for shadow
oBrush.Color = cShadow;
oGraphics.FillEllipse(oBrush, oRectShadow);
// get reference to collection of data rows
DataRowCollection colRows = dsData.Tables[0].Rows;
// calculate left positin of "value key" boxes
int iKeyBoxLeft = iPieDiameter + 45;
// calculate vertical spacing for "value key" boxes
int iKeyBoxSpace = (oBitMap.Height - iCaptionHeight - 15) / (colRows.Count - 1);
// declare variables we"ll need
DataRow oRow; // reference to data row
int iRowIndex = 0; // index for current row
float fSliceStart = 0; // start degrees of slice
float fSliceDegrees; // number of degrees for slice
int iKeyBoxTop; // vertical offset of "key" box
Double fTotalValue = 0; // total of all values in table
// variables to hold values extracted from rows
String sSliceCaption;
Double fSliceValue;
// calculate total of all values in data table
// iterate through the rows in the table
foreach (DataRow oERow in colRows) {
try {
fTotalValue += (Double)oERow[1];
}
catch {}
}
// now ready to draw the pie chart itself
// iterate through the rows in the table again
foreach (DataRow oERow in colRows) {
// calculate vertical position of "key" box
iKeyBoxTop = iCaptionHeight + (iKeyBoxSpace * iRowIndex);
// draw shadow for "key" box
oBrush.Color = cShadow;
oGraphics.FillRectangle(oBrush, iKeyBoxLeft + 3, iKeyBoxTop + 3, 15, 14);
// get values from data row
try {
sCaption = (String)oERow[0];
fSliceValue = (Double)oERow[1];
}
catch {
sCaption = "Error";
fSliceValue = 0;
}
// convert to number of degrees for this value
fSliceDegrees = (float)((fSliceValue / fTotalValue) * 360);
// set brush color from array of colors
oBrush.Color = aColors[iRowIndex];
// draw filled pie slice and then outline in black
oGraphics.FillPie(oBrush, oRectPie, fSliceStart, fSliceDegrees);
oGraphics.DrawPie(oPen, oRectPie, fSliceStart, fSliceDegrees);
// draw filled "key" rectangle and then outline in black
oGraphics.FillRectangle(oBrush, iKeyBoxLeft, iKeyBoxTop, 15, 14);
oGraphics.DrawRectangle(oPen, iKeyBoxLeft, iKeyBoxTop, 15, 14);
// draw caption text next to "key" box
DrawText(oGraphics, iKeyBoxLeft + 22, iKeyBoxTop,
oBitMap.Width - iKeyBoxLeft + 22, 14, sCaption,
FontStyle.Bold, 9, "", null, 0);
// save start position for next slice and increment row index
fSliceStart += fSliceDegrees;
iRowIndex += 1;
}
// write bitmap to response
oBitMap.Save(Response.OutputStream, ImageFormat.Gif);
oBitMap.Save(MapPath("piechart.gif"), ImageFormat.Gif);
// dispose of objects
oPen.Dispose();
oBrush.Dispose();
oGraphics.Dispose();
oBitMap.Dispose();
} // ------------------------------------------------------------------- // routine to draw text string in rectangle on bitmap void DrawText(Graphics oGraphics, int iTop, int iLeft, int iWidth,
int iHeight, String sText, object eFontStyle,
int iFontSize, String sColor, object eAlign,
StringFormatFlags eFlag) {
// set default values if not specified
if (eFontStyle == null) eFontStyle = FontStyle.Regular;
if (iFontSize == 0) iFontSize = 8;
if (sColor == "") sColor = "Black";
if (eAlign == null) eAlign = StringAlignment.Near;
// create the rectange to hold the text
RectangleF oRect = new RectangleF(iTop, iLeft, iWidth, iHeight);
// create a Font object for the text style
Font oFont = new Font("Arial", iFontSize, (FontStyle)eFontStyle);
// create the format object to define the format and style
StringFormat oFormat = new StringFormat(eFlag);
oFormat.Alignment = (StringAlignment)eAlign; // horizontal alignment
// always center vertically within rectangle area
oFormat.LineAlignment = StringAlignment.Center;
// create a brush object and draw the text
SolidBrush oBrush = new SolidBrush(Color.FromName(sColor));
oGraphics.DrawString(sText, oFont, oBrush, oRect, oFormat);
} // ------------------------------------------------------------------- Color[] GetColorArray() {
// declare an Array for 20 colors Color[] aColors = new Color[20]; // fill the array of colors for chart items // use browser-safe colors (multiples of #33) aColors[0] = Color.FromArgb(204, 0, 0); // red aColors[1] = Color.FromArgb(255, 153, 0); // orange aColors[2] = Color.FromArgb(255, 255, 0); // yellow aColors[3] = Color.FromArgb(0 ,255, 0); // green aColors[4] = Color.FromArgb(0, 255, 255); // cyan aColors[5] = Color.FromArgb(51, 102, 255); // blue aColors[6] = Color.FromArgb(255, 0, 255); // magenta aColors[7] = Color.FromArgb(102, 0, 102); // purple aColors[8] = Color.FromArgb(153, 0, 0); // dark red aColors[9] = Color.FromArgb(153, 153, 0); // khaki aColors[10] = Color.FromArgb(0, 102, 0); // dark green aColors[11] = Color.FromArgb(51, 51, 102); // dark blue aColors[12] = Color.FromArgb(102, 51, 0); // brown aColors[13] = Color.FromArgb(204, 204, 204); // light gray aColors[14] = Color.FromArgb(0, 0, 0); // black aColors[15] = Color.FromArgb(102, 204, 255); // sky aColors[16] = Color.FromArgb(255, 204, 255); // pink aColors[17] = Color.FromArgb(255, 255, 204); // chiffon aColors[18] = Color.FromArgb(255, 204, 204); // flesh aColors[19] = Color.FromArgb(153, 255, 204); // pale green return aColors;
} // ------------------------------------------------------------------- // function to create a DataSet containing a few values DataSet GetDataSet() {
// create a new DataSet object and a new table
DataSet dsResult = new DataSet();
DataTable tblData = new DataTable("Data");
dsResult.Tables.Add(tblData);
// define two columns (fields) within the table
tblData.Columns.Add("Caption", System.Type.GetType("System.String"));
tblData.Columns.Add("Value", System.Type.GetType("System.Double"));
// declare a variable to hold a DataRow object
// fill in the values and add to table then repeat
DataRow oRow = tblData.NewRow();
oRow["Caption"] = "Wrampant 1.6 16V";
oRow["Value"] = 277;
tblData.Rows.Add(oRow);
oRow = tblData.NewRow();
oRow["Caption"] = "Wrampant 2.0i 16V";
oRow["Value"] = 381;
tblData.Rows.Add(oRow);
oRow = tblData.NewRow();
oRow["Caption"] = "Wranger 2.5 D V6";
oRow["Value"] = 63;
tblData.Rows.Add(oRow);
oRow = tblData.NewRow();
oRow["Caption"] = "Wranger 3.2 D V6";
oRow["Value"] = 158;
tblData.Rows.Add(oRow);
oRow = tblData.NewRow();
oRow["Caption"] = "Wranger 4.8 V8";
oRow["Value"] = 106;
tblData.Rows.Add(oRow);
oRow = tblData.NewRow();
oRow["Caption"] = "Wregal 2.8 V6";
oRow["Value"] = 63;
tblData.Rows.Add(oRow);
oRow = tblData.NewRow();
oRow["Caption"] = "Wregal 3.2 D V6";
oRow["Value"] = 19;
tblData.Rows.Add(oRow);
oRow = tblData.NewRow();
oRow["Caption"] = "Wresponse 2.8 V6";
oRow["Value"] = 28;
tblData.Rows.Add(oRow);
oRow = tblData.NewRow();
oRow["Caption"] = "Wresponse 4.8 V8";
oRow["Value"] = 42;
tblData.Rows.Add(oRow);
oRow = tblData.NewRow();
oRow["Caption"] = "Wroadster 6.2 V12";
oRow["Value"] = 17;
tblData.Rows.Add(oRow);
return dsResult; // return DataSet
} // ------------------------------------------------------------------- </script>
</source>
ColorTranslator.FromHtml
<source lang="csharp">
<%@ Page Language="C#" %> <%@Import namespace="System.Collections"%> <%@Import namespace="System.Drawing"%> <script language="C#" runat="server"> private void Page_Load(object sender, System.EventArgs e) {
Hashtable myHash=new Hashtable();
myHash.Add("Red", "#FF0000");
myHash.Add("Green", "#00FF00");
myHash.Add("Blue", "#0000FF");
MyLabel.BackColor=ColorTranslator.FromHtml(myHash["Blue"].ToString());
MyLabel.ForeColor=ColorTranslator.FromHtml(myHash["Red"].ToString());
myHash=null;
} </script> <HTML>
<body>
<form id="form1" method="post" runat="server">
<asp:Label ID="MyLabel" Runat="server">Sample Text</asp:Label>
</form>
</body>
</HTML>
</source>
Create Color object from string (VB.net)
<source lang="csharp">
<%@ Page Language="VB" %> <script runat="server">
Dim ColorList(6) as String
Sub Page_Load
ColorList(0) = "Red"
ColorList(1) = "Orange"
ColorList(2) = "Yellow"
ColorList(3) = "Green"
ColorList(4) = "Blue"
ColorList(5) = "Indigo"
ColorList(6) = "Violet"
Array.Reverse(ColorList)
If Not Page.IsPostback
Dim ColorName as String
For Each ColorName in ColorList
ddlColorList.Items.Add(ColorName)
Next
End If
End Sub
Sub btnSelectColor_Click(sender As Object, e As EventArgs)
lblOutputMessage.Text = "You selected " & ddlColorList.SelectedItem.Value
lblOutputMessage.ForeColor = _
System.Drawing.Color.FromName(ddlColorList.SelectedItem.Text)
End Sub
</script> <html> <head> </head> <body>
<form runat="server">
Select a color from the list:<asp:DropDownList id="ddlColorList" runat="server"></asp:DropDownList> <asp:Button id="btnSelectColor" onclick="btnSelectColor_Click" runat="server" Text="Click here!"></asp:Button>
<asp:Label id="lblOutputMessage" runat="server"></asp:Label>
</form>
</body> </html>
</source>
NET Standard Color Names (C#)
<source lang="csharp">
<%-- Pro ASP.NET Web Forms Techniques, Second Edition By Alex Homer ISBN: 1-59059-317-0 Published: Dec 2003 Publisher: Apress.ru --%>
<%@Page Language="C#" %> <%@Import Namespace="System.Drawing" %> <script runat="server"> void Page_Load() {
Color[] aKnownCols = new Color[168];
KnownColor eValue;
for (eValue = 0; eValue <= KnownColor.YellowGreen; eValue++) {
aKnownCols[(int) eValue] = Color.FromKnownColor(eValue);
}
// create a table containing the .NET colors
// declare variables, we"ll create 5 rows simultaneously
TableRow oRow1, oRow2, oRow3, oRow4, oRow5;
TableCell oCell;
Color oKnown;
String sDecimalVals, sHexVals, sKnown;
int iCellCount = 0;
// to create empty cell with colored background
String sColorCell = " ";
// create empty Table object and five Row objects
Table oTable = new Table();
oRow1 = new TableRow();
oRow2 = new TableRow();
oRow3 = new TableRow();
oRow4 = new TableRow();
oRow5 = new TableRow();
// set horizontal alignment for three rows
oRow2.HorizontalAlign = HorizontalAlign.Center;
oRow3.HorizontalAlign = HorizontalAlign.Center;
oRow4.HorizontalAlign = HorizontalAlign.Center;
// iterate through array of safe colors
foreach (Color oColor in aKnownCols) {
iCellCount += 1; // increment cell counter
// create the strings showing decimal and hex RGB values
sDecimalVals = oColor.R.ToString() + "," + oColor.G.ToString()
+ "," + oColor.B.ToString();
sHexVals = "#" + oColor.R.ToString("x2") + oColor.G.ToString("x2")
+ oColor.B.ToString("x2");
sKnown = oColor.Name;
// create a new cell, and add LiteralControl containing value
oCell = new TableCell();
oCell.Controls.Add(new LiteralControl(sColorCell));
// set properties for this cell, and add to row 1
oCell.BorderColor = Color.Black;
oCell.BorderStyle = BorderStyle.Solid;
oCell.BorderWidth = Unit.Pixel(1);
oCell.BackColor = oColor;
oRow1.Cells.Add(oCell);
// repeat for cells containing decimal, hex and color name values
oCell = new TableCell();
oCell.Controls.Add(new LiteralControl(sDecimalVals));
oRow2.Cells.Add(oCell);
oCell = new TableCell();
oCell.Controls.Add(new LiteralControl(sHexVals));
oRow3.Cells.Add(oCell);
oCell = new TableCell();
oCell.Controls.Add(new LiteralControl(sKnown));
oRow4.Cells.Add(oCell);
// create cell in row 5 to provide space between color rows
oCell = new TableCell();
oCell.Controls.Add(new LiteralControl(" "));
oRow5.Cells.Add(oCell);
// start a new row every eight values
if ((int)(iCellCount / 8) == ((float)iCellCount / 8)) {
oTable.Rows.Add(oRow1);
oTable.Rows.Add(oRow2);
oTable.Rows.Add(oRow3);
oTable.Rows.Add(oRow4);
oTable.Rows.Add(oRow5);
oRow1 = new TableRow();
oRow2 = new TableRow();
oRow3 = new TableRow();
oRow4 = new TableRow();
oRow5 = new TableRow();
oRow2.HorizontalAlign = HorizontalAlign.Center;
oRow3.HorizontalAlign = HorizontalAlign.Center;
oRow4.HorizontalAlign = HorizontalAlign.Center;
}
}
ctlPlaceholder.Controls.Add(oTable);
} </script> <html> <head> <title>.NET Standard Color Names</title> </head> <body> .NET Standard Color Names<p /> <asp:PlaceHolder id="ctlPlaceholder" runat="server" /> </body> </html>
</source>
