android - 赋值不是表达式 - Kotlin
问题描述
我正在将使用 Java 构建的项目重构为 Kotlin,并从 sqlite 资产表中复制数据库,我正在这样做并且它工作正常。
private void copyDataBase() throws IOException {
InputStream mInput = mContext.getAssets().open(DB_NAME);
String outFileName = DB_PATH + DB_NAME;
OutputStream mOutput = new FileOutputStream(outFileName);
byte[] mBuffer = new byte[1024];
int mLength;
while ((mLength = mInput.read(mBuffer)) > 0) {
mOutput.write(mBuffer, 0, mLength);
}
mOutput.flush();
mOutput.close();
mInput.close();
}
如何处理“作业不是表达式,在这种情况下只允许表达式”?
@Throws(IOException::class)
private fun copyDataBase() {
val mInput = mContext.assets.open(DB_NAME)
val outFileName = DB_PATH + DB_NAME
val mOutput = FileOutputStream(outFileName)
val mBuffer = ByteArray(1024)
var mLength: Int
while ((mLength = mInput.read(mBuffer)) > 0) {
mOutput.write(mBuffer, 0, mLength)
}
mOutput.flush()
mOutput.close()
mInput.close()
}
错误在这里
while ((mLength = mInput.read(mBuffer)) > 0) {
mOutput.write(mBuffer, 0, mLength)
}
谢谢你。
解决方案
将其更改为:
mLength = mInput.read(mBuffer)
while (mLength > 0) {
mOutput.write(mBuffer, 0, mLength)
mLength = mInput.read(mBuffer)
}