主题：有关调用外部接口如何接收接口文件

得到的数据是base64的字符串，转换成文件即可。

如果是保存成图片，代码这样写

Dim str As String = "/9j/4AAQSkZJRgABAQAAAQABAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0a HBwgJC4nICIsIxwcKDcpLDAxNDQ0Hyc5PTgyPC4zNDL/2wBDAQkJCQwLDBgNDRgyIRwhMjIyMjIy MjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjL/wAARCAB2AFoDASIA AhEBAxEB/8QAHwAAAQUBAQEBAQEAAAAAAAAAAAECAwQFBgcICQoL/8QAtRAAAgEDAwIEAwUFBAQA AAF9AQIDAAQRBRIhMUEGE1FhByJxFDKBkaEII0KxwRVS0fAkM2JyggkKFhcYGRolJicoKSo0NTY3 ODk6Q0RFRkdISUpTVFVWV1hZWmNkZWZnaGlqc3R1dnd4eXqDhIWGh4iJipKTlJWWl5iZmqKjpKWm p6ipqrKztLW2t7i5usLDxMXGx8jJytLT1NXW19jZ2uHi4+Tl5ufo6erx8vP09fb3+Pn6/8QAHwEA AwEBAQEBAQEBAQAAAAAAAAECAwQFBgcICQoL/8QAtREAAgECBAQDBAcFBAQAAQJ3AAECAxEEBSEx BhJBUQdhcRMiMoEIFEKRobHBCSMzUvAVYnLRChYkNOEl8RcYGRomJygpKjU2Nzg5OkNERUZHSElK U1RVVldYWVpjZGVmZ2hpanN0dXZ3eHl6goOEhYaHiImKkpOUlZaXmJmaoqOkpaanqKmqsrO0tba3 uLm6wsPExcbHyMnK0tPU1dbX2Nna4uPk5ebn6Onq8vP09fb3+Pn6/9oADAMBAAIRAxEAPwD36iii gAoorlfGXjSz8K2oDgTXcgzHCD+p9BTSbdkB1JIUZNMM8YOC4z9a+f8AU/ib4g1W1khwkEZbJMAI IHoTXKnWr+GXzkvLlHJ+8srA/wA60VJ9WB9WggjI6UtfO+hfFPXtLkRZ5fttvnBSbrj2Yc/nmvZ/ C/i/T/FNoZbVisyAebA33k/xHvUyhKKuxtWOgY7RUROTmnOTnFMqBBRSE4FM3mgCypJGTTqgp8ZO cUAQ6lfw6Zp1xe3DbYoELt9AK+d92peOfEU85BJkfcefliXsPyr0r4w6q1p4ehsUbBu5Pnx3Vef5 4qh4A06Kz8OR3TqEEpLs78U3P2ceZdTalG7F0XwBaadEzPumdxzuHH5VkeIvAMMoDWaLE3U8V6bb 3dtPhIpkcgZwGGadJGrj7orlVWalzX1Ojlg9LHzpqXhq/wBLkZ5oWMQ/jApuia9c6FqkN7ZybJIz yOzjup9jXvV/awSQPHIisrDBDYryHxn4QTTg2oWAxCD88fp7j2rso4hS0mZzordHu+h6xb69o9vq Nt9yZclSeVbuD9DV9zgV4v8ABrxA8WoXOiSN+7mXzYsnow6j8R/KvZX6mlJWdjmasMdio4pnmH2p rHOTUFQ5JCNSiijsT6DNMDxP4vXE1/4ntrC2+byLYu+WAxknPX2Ar0e2trez0q2R4A6QxqoTHt6V 494lvVuviskkoUxG6SFgT24B/rXuSQiRQVOBjgVlXulFM6qaSRzkN5p17rM1s2liGeHGJNigNn0I 710MqbYcZxxwaJIEzvZVBHcCq1yygKp3Bemaxk7msY3Ocu30W01VILmO5nuZFZ1+dyuB1xzik1PT re40i5jjDNBJGSFY5xx710KWMD/N5aMxH3sVS1GNbSzmYYCrGxP5VN3pYpJI8H8E372HjG0uE6JM qkeoJwa+nS25FYd+a+TbCUxar5o7ODx9a+qbKVJrOKQEkMgINelX+JM4ZLqSSnPNRVJJ0FR1zOXY g1Kr3z+XYzN6IasVmeIJPK0S6YHH7s8/gauTsgPmHWbtptXluVYhvOLg+nORX0Z4b1CTUPDmnXj4 3zQIzEf3sc/rXzFfM32yQ8YDEfrXtvwo8QQX3hqPS3kUXVpkBCeWQnII+mcfl61piofulJLY6oPW zPQ7lgQMHkdqxJImWGGA3d03lSbyzOCX5ztY45FaVzbm4jKbivuDis2XSWOQFYHGM7zXAdVOMbWk y/aTJFbbQeR61zHjfVP7P8N310y7sJtCjjJJA/rWzGgtoxFuZivc85rzL4ta7GNNi0iKQNNI4klA 7KOmfx/lVUVzzUUQ9E2eX6a5e4ZmPJ5r6f8AB919q8MWL5yPKA/IYr5i0YZncfSvoL4Z3vneGUgB +aJiuK9HFXWpxtXOzf75ptKTk5pK4jI1KxPFkwh0Cdv8+tbdcN8RdatINCmt0lDTspBC84zxyfoT Wtr6FR3Pnqb53ye+TWr4QY23ifSG3FQbhQSD2PBqmOZk9O/4nFTW7/Yr+2mXrDMG49iDXZJ3i4m0 XZ3PpZWkiUFcMPQ9aZPcSqpbyfx3CpraVbizidDw6BvwplyMRFfWvHN4u7MO4eWWN5G+VF64r511 1nuNTvpySTJO5yT719JX6lNOdQAPlNfOt6o86TcD/rmH8668Do2TVexQ0kYaQV658Kr0fa7u3Y/e 5xXk8YEV4QBx1xXZ+AtSXTfECNIcJIpQ4+uRXZW1i2jA97ByM0VnW+pW0+Cr4JPAIxWgDkZrzwSs Rz3RmdkeYEDkKDwa8u+J0uyG0h3De5JOD1HFeqf2dApaYMR2BH615B8WT/xNrSMdETAPryKukrzR pG3Q88lcK5H5fpTbl/32fy/Sm3RAlGM4xUDsTKCTzxXocraJlufTXhgvL4ftCxB2xgVrtFu4zxWZ 4YlR/D9myxbT5KlsNxnFbPmMoUbcZ6ZryOVlOXYx9Si3W8voFIFfOmvoLe7dP4t+TjtX0hqLk20w 2D8AP614B40tMXDXDDmWZhnsQOn9a6cKmqgSd0c/Kudhbk4//VVvR5/K1CB2+6rgn6DmqhJ+zo56 4zS22VueB1IIrub91ozPcNNuILtlCoQyjaFweRx/hW+qkIoDSgY/vGsbw3CoSGWADMiqM49hn+dd wsaBQNvQV5jtfQpSaEkJX5X2qeeCfbj9a8V+KjCTX4sbcpHzj6//AFq9vvCuMOcIOTXhnxD/AHvi KQ5ZsgdeoxmtKXxhDc4GfJG4dTn+dQ24M15DEPvOwUfyrQljOwY6AZNV9OQJq8JwCVdevTNd/MnF jauz6M0ETw2MUO0bBgdc8Y65rYHmjJYMRzjI4qhomH0yF/MjO7GADxnjIrVYtypl+XO0sW6+1eYK UrlB0kmQrcKSgII7YPOK8I8eIV11ISzHaxBB7HNfQMuERv3qDbwRkcGvCvH1sq+LnCurnaCSDkA1 tQdp3BybOKlG2z/3XI/Slt281UJ4IbtUt+mIHK9Mlqi005k29t6/4V26ctyT6A8HErplqQD80Sk5 GO3FdoFBAri/DLNHDbw42hI1GPXiu1H3R9K8tO+o2rMrasxWDIxkV4j4zm+0eI7gjdgIoG7r8wFF Fa0viLhsctMgMmAON2PyrOgQD97j5i+7NFFdkdg+0fSfhrE/h21lVFVyvJA6gVquFVidq4GSBtGO Bnn35oorzyZbj9iEsQg28hc9iK8I8XOZvE8rnA6D9KKK0pfEScTfL+6jHbj+tJpHzzBfVs/rRRXo S/hsZ754ZB8pGZizMckmuyX7o+lFFeWI/9k="
try
    Dim bs As Byte() = Convert.FromBase64String(str)
    Dim stream As System.IO.Stream = New System.IO.MemoryStream(bs)
    Dim bmp As System.Drawing.Bitmap = New System.Drawing.Bitmap(stream)
    bmp.Save("d:\test.jpg", System.Drawing.Imaging.ImageFormat.Jpeg)
catch ex As exception
    msgbox("出错")
End try

如果是保存成文件，这样写

Dim str As String = "/9j/4AAQSkZJRgABAQAAAQABAAD/2wBDAAgGBgcGBQgHBwcJCQgKDBQNDAsLDBkSEw8UHRofHh0a HBwgJC4nICIsIxwcKDcpLDAxNDQ0Hyc5PTgyPC4zNDL/2wBDAQkJCQwLDBgNDRgyIRwhMjIyMjIy MjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjIyMjL/wAARCAB2AFoDASIA AhEBAxEB/8QAHwAAAQUBAQEBAQEAAAAAAAAAAAECAwQFBgcICQoL/8QAtRAAAgEDAwIEAwUFBAQA AAF9AQIDAAQRBRIhMUEGE1FhByJxFDKBkaEII0KxwRVS0fAkM2JyggkKFhcYGRolJicoKSo0NTY3 ODk6Q0RFRkdISUpTVFVWV1hZWmNkZWZnaGlqc3R1dnd4eXqDhIWGh4iJipKTlJWWl5iZmqKjpKWm p6ipqrKztLW2t7i5usLDxMXGx8jJytLT1NXW19jZ2uHi4+Tl5ufo6erx8vP09fb3+Pn6/8QAHwEA AwEBAQEBAQEBAQAAAAAAAAECAwQFBgcICQoL/8QAtREAAgECBAQDBAcFBAQAAQJ3AAECAxEEBSEx BhJBUQdhcRMiMoEIFEKRobHBCSMzUvAVYnLRChYkNOEl8RcYGRomJygpKjU2Nzg5OkNERUZHSElK U1RVVldYWVpjZGVmZ2hpanN0dXZ3eHl6goOEhYaHiImKkpOUlZaXmJmaoqOkpaanqKmqsrO0tba3 uLm6wsPExcbHyMnK0tPU1dbX2Nna4uPk5ebn6Onq8vP09fb3+Pn6/9oADAMBAAIRAxEAPwD36iii gAoorlfGXjSz8K2oDgTXcgzHCD+p9BTSbdkB1JIUZNMM8YOC4z9a+f8AU/ib4g1W1khwkEZbJMAI IHoTXKnWr+GXzkvLlHJ+8srA/wA60VJ9WB9WggjI6UtfO+hfFPXtLkRZ5fttvnBSbrj2Yc/nmvZ/ C/i/T/FNoZbVisyAebA33k/xHvUyhKKuxtWOgY7RUROTmnOTnFMqBBRSE4FM3mgCypJGTTqgp8ZO cUAQ6lfw6Zp1xe3DbYoELt9AK+d92peOfEU85BJkfcefliXsPyr0r4w6q1p4ehsUbBu5Pnx3Vef5 4qh4A06Kz8OR3TqEEpLs78U3P2ceZdTalG7F0XwBaadEzPumdxzuHH5VkeIvAMMoDWaLE3U8V6bb 3dtPhIpkcgZwGGadJGrj7orlVWalzX1Ojlg9LHzpqXhq/wBLkZ5oWMQ/jApuia9c6FqkN7ZybJIz yOzjup9jXvV/awSQPHIisrDBDYryHxn4QTTg2oWAxCD88fp7j2rso4hS0mZzordHu+h6xb69o9vq Nt9yZclSeVbuD9DV9zgV4v8ABrxA8WoXOiSN+7mXzYsnow6j8R/KvZX6mlJWdjmasMdio4pnmH2p rHOTUFQ5JCNSiijsT6DNMDxP4vXE1/4ntrC2+byLYu+WAxknPX2Ar0e2trez0q2R4A6QxqoTHt6V 494lvVuviskkoUxG6SFgT24B/rXuSQiRQVOBjgVlXulFM6qaSRzkN5p17rM1s2liGeHGJNigNn0I 710MqbYcZxxwaJIEzvZVBHcCq1yygKp3Bemaxk7msY3Ocu30W01VILmO5nuZFZ1+dyuB1xzik1PT re40i5jjDNBJGSFY5xx710KWMD/N5aMxH3sVS1GNbSzmYYCrGxP5VN3pYpJI8H8E372HjG0uE6JM qkeoJwa+nS25FYd+a+TbCUxar5o7ODx9a+qbKVJrOKQEkMgINelX+JM4ZLqSSnPNRVJJ0FR1zOXY g1Kr3z+XYzN6IasVmeIJPK0S6YHH7s8/gauTsgPmHWbtptXluVYhvOLg+nORX0Z4b1CTUPDmnXj4 3zQIzEf3sc/rXzFfM32yQ8YDEfrXtvwo8QQX3hqPS3kUXVpkBCeWQnII+mcfl61piofulJLY6oPW zPQ7lgQMHkdqxJImWGGA3d03lSbyzOCX5ztY45FaVzbm4jKbivuDis2XSWOQFYHGM7zXAdVOMbWk y/aTJFbbQeR61zHjfVP7P8N310y7sJtCjjJJA/rWzGgtoxFuZivc85rzL4ta7GNNi0iKQNNI4klA 7KOmfx/lVUVzzUUQ9E2eX6a5e4ZmPJ5r6f8AB919q8MWL5yPKA/IYr5i0YZncfSvoL4Z3vneGUgB +aJiuK9HFXWpxtXOzf75ptKTk5pK4jI1KxPFkwh0Cdv8+tbdcN8RdatINCmt0lDTspBC84zxyfoT Wtr6FR3Pnqb53ye+TWr4QY23ifSG3FQbhQSD2PBqmOZk9O/4nFTW7/Yr+2mXrDMG49iDXZJ3i4m0 XZ3PpZWkiUFcMPQ9aZPcSqpbyfx3CpraVbizidDw6BvwplyMRFfWvHN4u7MO4eWWN5G+VF64r511 1nuNTvpySTJO5yT719JX6lNOdQAPlNfOt6o86TcD/rmH8668Do2TVexQ0kYaQV658Kr0fa7u3Y/e 5xXk8YEV4QBx1xXZ+AtSXTfECNIcJIpQ4+uRXZW1i2jA97ByM0VnW+pW0+Cr4JPAIxWgDkZrzwSs Rz3RmdkeYEDkKDwa8u+J0uyG0h3De5JOD1HFeqf2dApaYMR2BH615B8WT/xNrSMdETAPryKukrzR pG3Q88lcK5H5fpTbl/32fy/Sm3RAlGM4xUDsTKCTzxXocraJlufTXhgvL4ftCxB2xgVrtFu4zxWZ 4YlR/D9myxbT5KlsNxnFbPmMoUbcZ6ZryOVlOXYx9Si3W8voFIFfOmvoLe7dP4t+TjtX0hqLk20w 2D8AP614B40tMXDXDDmWZhnsQOn9a6cKmqgSd0c/Kudhbk4//VVvR5/K1CB2+6rgn6DmqhJ+zo56 4zS22VueB1IIrub91ozPcNNuILtlCoQyjaFweRx/hW+qkIoDSgY/vGsbw3CoSGWADMiqM49hn+dd wsaBQNvQV5jtfQpSaEkJX5X2qeeCfbj9a8V+KjCTX4sbcpHzj6//AFq9vvCuMOcIOTXhnxD/AHvi KQ5ZsgdeoxmtKXxhDc4GfJG4dTn+dQ24M15DEPvOwUfyrQljOwY6AZNV9OQJq8JwCVdevTNd/MnF jauz6M0ETw2MUO0bBgdc8Y65rYHmjJYMRzjI4qhomH0yF/MjO7GADxnjIrVYtypl+XO0sW6+1eYK UrlB0kmQrcKSgII7YPOK8I8eIV11ISzHaxBB7HNfQMuERv3qDbwRkcGvCvH1sq+LnCurnaCSDkA1 tQdp3BybOKlG2z/3XI/Slt281UJ4IbtUt+mIHK9Mlqi005k29t6/4V26ctyT6A8HErplqQD80Sk5 GO3FdoFBAri/DLNHDbw42hI1GPXiu1H3R9K8tO+o2rMrasxWDIxkV4j4zm+0eI7gjdgIoG7r8wFF Fa0viLhsctMgMmAON2PyrOgQD97j5i+7NFFdkdg+0fSfhrE/h21lVFVyvJA6gVquFVidq4GSBtGO Bnn35oorzyZbj9iEsQg28hc9iK8I8XOZvE8rnA6D9KKK0pfEScTfL+6jHbj+tJpHzzBfVs/rRRXo S/hsZ754ZB8pGZizMckmuyX7o+lFFeWI/9k="
Dim bs() As Byte = Convert.FromBase64String(str)
Dim ms As New IO.FileStream("d:\000.jpg", IO.FileMode.Create)
ms.Write(bs, 0,bs.length)
ms.close