如何在java

Question

我开发了一款小型Android应用。我使用了final关键字并在create方法中初始化了资源imageView。我已经定义了一个私有方法，我在其中使用了imageview但它在左侧给了我红色标记。拜托，有谁能帮我怎么写。这个计划。我在这里先向您的帮助表示感谢。

SecondActivity.java

public class SecondActivity extends Activity {

    Button btnPrevious= null;
    Button btnNext = null;
    TextView txtTest = null;

    int conditions[];
    String days[];

    // condition imageView initialization together with declaration 

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.second_activity);

        //ImageView Initialization


        btnPrevious =  (Button) findViewById(R.id.btnPrevious2);
        btnNext =  (Button) findViewById(R.id.btnNext2);
        txtTest = (TextView) findViewById(R.id.txtTest2);

        final ImageView T1C4R4 = (ImageView) findViewById(R.id.T1C4R4);
        final ImageView T2C4R5 = (ImageView) findViewById(R.id.T2C4R5);
        final ImageView T4C4R1 = (ImageView) findViewById(R.id.T4C4R1);
        final ImageView T3C4R1 = (ImageView) findViewById(R.id.T3C4R1);

        // imageView initialization together with declaration

        final ImageView T1C4R1 = (ImageView) findViewById(R.id.T1C4R1); 
        final ImageView T1C2R3 = (ImageView) findViewById(R.id.T1C2R3);
        final ImageView T1C1R4 = (ImageView) findViewById(R.id.T1C1R4);

        final ImageView T2C4R1 = (ImageView) findViewById(R.id.T2C4R1);
        final ImageView T2C2R3 = (ImageView) findViewById(R.id.T2C2R3);
        final ImageView T2C1R5 = (ImageView) findViewById(R.id.T2C1R5);

        final ImageView T4C1R1 = (ImageView) findViewById(R.id.T4C1R1);
        final ImageView T4C2R2 = (ImageView) findViewById(R.id.T4C2R2);
        final ImageView T4C5R5 = (ImageView) findViewById(R.id.T4C5R5);

        final ImageView T3C4R5 = (ImageView) findViewById(R.id.T3C4R5);
        final ImageView T3C2R3 = (ImageView) findViewById(R.id.T3C2R3);
        final ImageView T3C1R1 = (ImageView) findViewById(R.id.T3C1R1);

        final ImageView[][] dressImageView =
            {
                {T1C4R1, T1C2R3, T1C1R4},
                {T2C4R1,T2C2R3, T2C1R5} ,
                {T4C1R1, T4C2R2,T4C5R5},
                {T3C4R5, T3C2R3, T3C1R1}
            }; 

        final ImageView [] dayCell = {T1C4R4 ,T2C4R5, T4C4R1, T3C4R1 };


        // get the Intent that started this Activity
        Intent in = getIntent();

        // get the Bundle that stores the data of this Activity
        Bundle b = in.getExtras();

        // getting data from bundle
        conditions = b.getIntArray("condition");
        days = b.getStringArray("day");

        // show data to layout
        txtTest.setText("[Condition: " + conditions[0] + ", " + conditions[1] + ", " + conditions[2] + ", " + conditions[3] + "]");

        for (int c = 0; c < conditions.length; c++) {
            //dayWeatherCondtion(dc, days[dc]);                  
            weatherCondition(c, conditions[c]);         
        }
        btnPrevious.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub

            }

        });

        btnNext.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Bundle b = new Bundle();

                b.putInt("condition", conditions[1]);
                b.putString("day", days[1]);

                // Creating Intent object
                Intent in = new Intent(SecondActivity.this, DetailActivity.class);

                // Storing bundle object into intent
                in.putExtras(b);
                startActivity(in);
            }
        });
    }

    private void weatherCondition(int day, int condition) {   

        switch(condition){
        case 10: 
        {
            //String dress_array[] = ;
            weatherDress(day, getResources().getStringArray(R.array.five));      
            break;
        }
        case 5:
        case 6:
        {
            //  String dress_array[] = getResources().getStringArray(R.array.five);
            weatherDress(day, getResources().getStringArray(R.array.five));
            break;
        }
    }
    }

private void weatherDress(int day, String[] dress_array) {
        for(int d = 0; d  < dress_array.length; d++ ){
            //ImageView temp = dressImageView[d];

        dressImageView[day][d].setImageDrawable(getDrawableByName(SecondActivity.this, dress_array[d]));

        }
    }

    public Drawable getDrawableByName(Context context, String name){
        Resources resources = context.getResources();
        final int resourceId = resources.getIdentifier(name, "drawable", 
                context.getPackageName());
        return resources.getDrawable(resourceId);
    }

}

Answer 1

您的私有方法似乎正在尝试访问 null 的第一个final ImageView T1C4R4;。

当您创建最终变量时，您必须初始化它，因为您将无法使用其他值重新分配它。

Answer 2

Vyas的

我不知道你想要用这个代码实现什么，但是我可以为你解决问题

您需要在使用该对象的地方递归传递dressImageView对象的引用

例如

weatherCondition(c, conditions[c], dressImageView);
.....
case 10:
    {
        //String dress_array[] = ;
        weatherDress(day, getResources().getStringArray(R.array.five),dressImageView);
        break;
    }
....