/// <summary>
/// 使用byte[]数据,生成256色灰度 BMP 位图
/// </summary>
/// <param name="originalImageData"></param>
/// <param name="originalWidth"></param>
/// <param name="originalHeight"></param>
/// <returns></returns>
public static Bitmap CreateBitmap(byte[] originalImageData, int originalWidth, int originalHeight)
{
//指定8位格式,即256色
Bitmap resultBitmap = new Bitmap(originalWidth, originalHeight, System.Drawing.Imaging.PixelFormat.Format8bppIndexed)
//将该位图存入内存中
MemoryStream curImageStream = new MemoryStream()
resultBitmap.Save(curImageStream, System.Drawing.Imaging.ImageFormat.Bmp)
curImageStream.Flush()
//由于位图数据需要DWORD对齐(4byte倍数),计算需要补位的个数
int curPadNum = ((originalWidth * 8 + 31) / 32 * 4) - originalWidth
//最终生成的位图数据大小
int bitmapDataSize = ((originalWidth * 8 + 31) / 32 * 4) * originalHeight
//数据部分相对文件开始偏移,具体可以参考位图文件格式
int dataOffset = ReadData(curImageStream, 10, 4)
//改变调色板,因为默认的调色板是32位彩色的,需要修改为256色的调色板
int paletteStart = 54
int paletteEnd = dataOffset
int color = 0
for (int i = paletteStarti <paletteEndi += 4)
{
byte[] tempColor = new byte[4]
tempColor[0] = (byte)color
tempColor[1] = (byte)color
tempColor[2] = (byte)color
tempColor[3] = (byte)0
color++
curImageStream.Position = i
curImageStream.Write(tempColor, 0, 4)
}
//最终生成的位图数据,以及大小,高度没有变,宽度需要调整
byte[] destImageData = new byte[bitmapDataSize]
int destWidth = originalWidth + curPadNum
//生成最终的位图数据,注意的是,位图数据 从左到右,从下到上,所以需要颠倒
for (int originalRowIndex = originalHeight - 1originalRowIndex >= 0originalRowIndex--)
{
int destRowIndex = originalHeight - originalRowIndex - 1
for (int dataIndex = 0dataIndex <originalWidthdataIndex++)
{
//同时还要注意,新的位图数据的宽度已经变化destWidth,否则会产生错位
destImageData[destRowIndex * destWidth + dataIndex] = originalImageData[originalRowIndex * originalWidth + dataIndex]
}
}
//将流的Position移到数据段
curImageStream.Position = dataOffset
//将新位图数据写入内存中
curImageStream.Write(destImageData, 0, bitmapDataSize)
curImageStream.Flush()
//将内存中的位图写入Bitmap对象
resultBitmap = new Bitmap(curImageStream)
return resultBitmap
}
/// <summary>
/// 从内存流中指定位置,读取数据
/// </summary>
/// <param name="curStream"></param>
/// <param name="startPosition"></param>
/// <param name="length"></param>
/// <returns></returns>
public static int ReadData(MemoryStream curStream, int startPosition, int length)
{
int result = -1
byte[] tempData = new byte[length]
curStream.Position = startPosition
curStream.Read(tempData, 0, length)
result = BitConverter.ToInt32(tempData, 0)
return result
}
/// <summary>
/// 向内存流中指定位置,写入数据
/// </summary>
/// <param name="curStream"></param>
/// <param name="startPosition"></param>
/// <param name="length"></param>
/// <param name="value"></param>
public static void WriteData(MemoryStream curStream, int startPosition, int length, int value)
{
curStream.Position = startPosition
curStream.Write(BitConverter.GetBytes(value), 0, length)
}
指定到 jsp ,那个jsp 里肯定有默认的请求发送。这种写法不是很普遍。 最普遍的是URL 直接写入要访问的服务器地址以及具体相对路径。这个要后台是GET 还是 POST ,查询一般是 GET。
form.getForm().submit({
url:.......,
waitMsg:'加载中....',
params:{
method:'login'
},
success:function(form, action){
//如果返回true则
Ext.MessageBox.alert("info","登录成功!")
},
failure : function(form, action) {
Ext.MessageBox.alert("info","登录失败!")
}
})
//形式差不多就是这样的。
Ext.create('Ext.grid.Panel',{title:'ActionColumnDemo',store:Ext.data.StoreManager.lookup('employeeStore'),columns:[{text:'FirstName',dataIndex:'firstname'},{text:'LastName',dataIndex:'lastname'},{xtype:'actioncolumn',width:50,items:欢迎分享,转载请注明来源:内存溢出
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