StreamWriter vs BinaryWriter
2011-09-06 07:53 symphony2010 阅读(232) 评论(0) 编辑 收藏 举报再用BinaryWriter写到一个txt文件里发现，里面的格式没有正常显示（显示为 带黑色矩形）：
然后就反汇编了这两个类（reflactor）：
BinaryWriter
public virtual void Write(string value)
{
int num1 = 0;
char* chrPointer = null;
if (value == null)
{
throw new ArgumentNullException("value");
}
int byteCount = this._encoding.GetByteCount(value);
this.Write7BitEncodedInt(byteCount);
if (this._largeByteBuffer == 0)
{
this._largeByteBuffer = new byte[256];
this._maxChars = 256 / this._encoding.GetMaxByteCount(1);
}
if (byteCount <= 256)
{
this._encoding.GetBytes(value, 0, value.Length, this._largeByteBuffer, 0);
this.OutStream.Write(this._largeByteBuffer, 0, byteCount);
return;
}
int num2 = 0;
for (int i = value.Length; i > 0; i = i - num1)
{
num1 = (i > this._maxChars ? this._maxChars : i);
fixed (string str = value)
{
if (byte[] numArray = this._largeByteBuffer || (int)numArray.Length == 0)
{
fixed (byte* numPointer = (byte*)((UIntPtr)0))
{
}
}
numPointer = numArray[0];
int bytes = this._encoder.GetBytes(chrPointer + num2, num1, (IntPtr)numPointer, 256, num1 == i);
fixed (numPointer = (byte*)((UIntPtr)0))
{
this.OutStream.Write(this._largeByteBuffer, 0, bytes);//在该方法下调试进入发现了InternalBlockCopy
num2 = num2 + num1;
}
}
}
}
StreamWriter
public override void Write(string value) { if (value != null) { int length = value.Length; int sourceIndex = 0; while (length > 0) { if (this.charPos == this.charLen) { this.Flush(false, false); } int count = this.charLen - this.charPos; if (count > length) { count = length; } value.CopyTo(sourceIndex, this.charBuffer, this.charPos, count); this.charPos += count; sourceIndex += count; length -= count; } if (this.autoFlush) { this.Flush(true, false); } } }InternalBlockCopy(array, offset, this._buffer, this._writePos, byteCount);
wstrcpy(chRef2 + destinationIndex, chRef + sourceIndex, count);
最后发现这两个类的差别就是以上两个方法的差别。
