TextView[][] 数组使应用程序崩溃，为什么？

Question

我想使用一个 TextView 数组。当我尝试在每个 TextView 数组（代码中嵌套的“for”循环）中设置每个 TextView 的文本时，应用程序崩溃。这是我的代码：

package com.example.whynotworking;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;

public class MainActivity extends Activity {

TextView[] FirstArray;
TextView[] SecondArray;
TextView[] ThirdArray;

int SizeOfTextViewArrays;

TextView[][] TheArrayArray = {FirstArray,SecondArray,ThirdArray};

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Log.d("DebugTAG", "no problems yet");

    SizeOfTextViewArrays = 5;

    FirstArray = new TextView[SizeOfTextViewArrays];
    SecondArray = new TextView[SizeOfTextViewArrays];
    ThirdArray = new TextView[SizeOfTextViewArrays];

    Log.d("DebugTAG", "still no problems");

    taskIwantToDo();
}

public void taskIwantToDo() {
    for (int i = 0; i < TheArrayArray.length; i++) {
    for (int j = 0; j < SizeOfTextViewArrays; j++) {
        Log.d("DebugTAG", "I see this log come up once");
        TheArrayArray[i][j].setText("Text to set...");
        Log.d("DebugTAG", "But I don't see this one...");
    }
    }
}
}

我认为问题的一部分是在 onCreate() 方法之外声明和启动的 TextView[][] 数组。但是当我尝试在 onCreate() 中启动它时，它（eclipse IDE）告诉我“数组常量只能在初始化程序中使用”...

LogCat 输出为：

07-05 21:08:20.346：D/DebugTAG(340)：还没有问题 07-05 21:08:20.346: D/DebugTAG(340): 仍然没有问题 07-05 21:08:20.346: D/DebugTAG(340): 我看到这个日志出现了一次

谢谢

Answer 1

您需要创建数组的内容：

public void taskIwantToDo() {
    for (int i = 0; i < TheArrayArray.length; i++) {
        for (int j = 0; j < SizeOfTextViewArrays; j++) {
            TheArrayArray[i][j] = new TextView(this); // <-- THIS LINE
            TheArrayArray[i][j].setText("Text to set...");
        }
    }
}

在此之前，您需要正确创建数组。要么在模块级别完成所有操作：

int SizeOfTextViewArrays = 5;

TextView[] FirstArray = new TextView[SizeOfTextViewArrays];
TextView[] SecondArray = new TextView[SizeOfTextViewArrays];
TextView[] ThirdArray = new TextView[SizeOfTextViewArrays];

TextView[][] TheArrayArray = {FirstArray,SecondArray,ThirdArray};

或者全部在onCreate:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Log.d("DebugTAG", "no problems yet");

    SizeOfTextViewArrays = 5;

    FirstArray = new TextView[SizeOfTextViewArrays];
    SecondArray = new TextView[SizeOfTextViewArrays];
    ThirdArray = new TextView[SizeOfTextViewArrays];

    TheArrayArray = {FirstArray,SecondArray,ThirdArray};