如何为最终变量赋值

Question

变量"startTs"需要声明为final。当我宣布它为最终版本时 android studio 突出显示它并说 "cant assign value to final variable" 如果删除最终修饰符，我会收到 "variable must be final"

现在我想使用变量 "startTs" 并为其赋值，该怎么做

请告诉我如何解决这个问题

代码:

final long startTs;

        mbtnLogFileAction.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                switch (action) {
                    case "Record":
                        Log.i(TAG, CSubTag.bullet("ATRx.onPreExecute", "start Recording logs"));

                        mbtnLogFileAction.setText("Pause");
                        metLogFileName.setEnabled(false);

                        String logFileName = metLogFileName.getText().toString();

                        if (logFileName != null && !logFileName.isEmpty()) {

                            if (!mLogFileHT.containsKey(logFileName)) {
                                startTs = TimeUtils.getTSSec();//cant assign value to final variable
                                mLogFileHT.put(logFileName, startTs);
                            } else {
                                startTs = mLogFileHT.get(logFileName);//cant assign value to final variable
                            }

Answer 1

因为您使用的是匿名内部 class ，startTs 必须在其中使用 final 并且因为它是 final ，所以它应该是一个编译时间常量并且不能被重新分配

Answer 2

只需将 startTs 全局放置即可。

public class YourClass
{


long startTs;

// your other code goes here..

        mbtnLogFileAction.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                switch (action) {
                    case "Record":
                        Log.i(TAG, CSubTag.bullet("ATRx.onPreExecute", "start Recording logs"));

                        mbtnLogFileAction.setText("Pause");
                        metLogFileName.setEnabled(false);

                        String logFileName = metLogFileName.getText().toString();

                        if (logFileName != null && !logFileName.isEmpty()) {

                            if (!mLogFileHT.containsKey(logFileName)) {
                                startTs = TimeUtils.getTSSec();//cant assign value to final variable
                                mLogFileHT.put(logFileName, startTs);
                            } else {
                                startTs = mLogFileHT.get(logFileName);//cant assign value to final variable
                            }

}

Answer 3

final成员变量必须在声明时或构造函数内部初始化，否则会导致编译错误。

如何为最终变量赋值

How to assign value to a final variable

java

android

final