Question

你有一些我无法解决的问题，google和搜索无法找到任何东西所以请帮忙。

我使用的东西（不是按顺序）

String[] SDCard = {"/sdcard/WhatToEat/Dishes.txt/"};
EditText mTextInput;
ListView mtextOutput;






    @Override
public void onClick(View v) {
    if (v.getId()==R.id.save) {
        File WriteSD =new File("/sdcard/WhatToEat/");
        String[] SDCard = {"/sdcard/WhatToEat/Dishes.txt/"};

        if(WriteSD.exists()){
            try {
                WriteSD.createNewFile();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        FileWriter fileWritter = null;
        try {
            fileWritter = new FileWriter(WriteSD.getName(),true);
        } catch (IOException e2) {
            // TODO Auto-generated catch block
            e2.printStackTrace();
        }
        BufferedWriter bufferWritter = new BufferedWriter(fileWritter);
        try {
            bufferWritter.write("/sdcard/WhatToEat/WriteSD/Dishes.txt/");
        } catch (IOException e1) {
            // TODO Auto-generated catch block
        e1.printStackTrace();
    }
    try {
        bufferWritter.flush();
    } catch (IOException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }
    try {
        bufferWritter.close();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();

        String text = mTextInput.getText().toString();
        WriteSD.setText(text+"/n"+SDCard.getText().toString());

getText（）上的错误 - 无法在数组类型String []上调用getText（）任何修复或四处走动？在此先感谢：）

logcat的

05-16 16:48:12.180: D/dalvikvm(803): GC_FOR_ALLOC freed 73K, 5% free 2908K/3048K, paused 33ms, total 35ms
05-16 16:48:12.180: I/dalvikvm-heap(803): Grow heap (frag case) to 3.377MB for 500416-byte allocation
05-16 16:48:12.220: D/dalvikvm(803): GC_FOR_ALLOC freed 2K, 5% free 3394K/3540K, paused 39ms, total 39ms
05-16 16:48:12.270: D/AndroidRuntime(803): Shutting down VM
05-16 16:48:12.270: W/dalvikvm(803): threadid=1: thread exiting with uncaught exception (group=0xb3a86ba8)
05-16 16:48:12.280: E/AndroidRuntime(803): FATAL EXCEPTION: main
05-16 16:48:12.280: E/AndroidRuntime(803): Process: com.example.whattoeat, PID: 803
05-16 16:48:12.280: E/AndroidRuntime(803): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.whattoeat/com.example.whattoeat.MainActivity}: java.lang.NullPointerException
05-16 16:48:12.280: E/AndroidRuntime(803):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
05-16 16:48:12.280: E/AndroidRuntime(803):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
05-16 16:48:12.280: E/AndroidRuntime(803):  at android.app.ActivityThread.access$800(ActivityThread.java:135)
05-16 16:48:12.280: E/AndroidRuntime(803):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
05-16 16:48:12.280: E/AndroidRuntime(803):  at android.os.Handler.dispatchMessage(Handler.java:102)
05-16 16:48:12.280: E/AndroidRuntime(803):  at android.os.Looper.loop(Looper.java:136)
05-16 16:48:12.280: E/AndroidRuntime(803):  at android.app.ActivityThread.main(ActivityThread.java:5017)
05-16 16:48:12.280: E/AndroidRuntime(803):  at java.lang.reflect.Method.invokeNative(Native Method)
05-16 16:48:12.280: E/AndroidRuntime(803):  at java.lang.reflect.Method.invoke(Method.java:515)
05-16 16:48:12.280: E/AndroidRuntime(803):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
05-16 16:48:12.280: E/AndroidRuntime(803):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
05-16 16:48:12.280: E/AndroidRuntime(803):  at dalvik.system.NativeStart.main(Native Method)
05-16 16:48:12.280: E/AndroidRuntime(803): Caused by: java.lang.NullPointerException
05-16 16:48:12.280: E/AndroidRuntime(803):  at com.example.whattoeat.MainActivity.setupWidgets(MainActivity.java:102)
05-16 16:48:12.280: E/AndroidRuntime(803):  at com.example.whattoeat.MainActivity.onCreate(MainActivity.java:44)
05-16 16:48:12.280: E/AndroidRuntime(803):  at android.app.Activity.performCreate(Activity.java:5231)
05-16 16:48:12.280: E/AndroidRuntime(803):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
05-16 16:48:12.280: E/AndroidRuntime(803):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
05-16 16:48:12.280: E/AndroidRuntime(803):  ... 11 more

setupWidgets

private void setupWidgets() {
        Button save=(Button) findViewById(R.id.save);
        save.setOnClickListener(this);
        mTextInput=(EditText) findViewById(R.id.textView);
        mtextOutput=(ListView) findViewById(R.id.textOutput);

Answer 1

为什么要使用数组？你不能使用常规字符串吗？

无论如何，这应该有效

WriteSD.setText(text+"/n"+SDCard[0]);

Answer 2

您将SDCard声明为一个String对象数组，其中包含一个String，而不是一个String。

您可以通过将SDCard声明更改为

来解决此问题

String SDCard = "/sdcard/WhatToEat/Dishes.txt/";

无法在数组类型String []上调用getText（）

2 个答案: