如何使用 foreach 循环来清理这个冗长的代码补丁？

Question

Java/Android 初学者在这里。我在我的应用程序中使用了自定义字体，并且为每段文本创建 setTypeface() 语句会影响我的代码质量。

当前代码：

Typeface Helvetica = Typeface.createFromAsset(getAssets(), "fonts/Helvetica.otf");

final TextView Nike = (TextView)findViewById(R.id.Nike);
final TextView Puma = (TextView)findViewById(R.id.Puma);
final TextView Adidas = (TextView)findViewById(R.id.Adidas);
final TextView Reebok = (TextView)findViewById(R.id.Reebok);
final TextView Umbro = (TextView)findViewById(R.id.Umbro);

Nike.setTypeface(Helvetica);
Puma.setTypeface(Helvetica);
Adidas.setTypeface(Helvetica);
Reebok.setTypeface(Helvetica);
Umbro.setTypeface(Helvetica);

如何缩短此代码？我正在考虑一个带有数组的 foreach 循环，但我似乎无法弄清楚。这样的事情是否可能：

String[] HelveticaTextArray = {"Nike", "Puma", "Adidas", "Reebok", "Umbro"};

for ( String[] HelveticaTextArray : item ) {
    final TextView HelveticaText = (TextView).findViewById(R.id.item);
    HelveticaText.setTypeface(Helvetica);
};

Answer 1

由于您为每个TextView 做同样的事情，我倾向于创建一个方便的方法来满足您的需要，传入R.id.xxx 和字体。例如，

private void initializeViews() {
    Typeface Helvetica = Typeface.createFromAsset(getAssets(), "fonts/Helvetica.otf");

    final TextView Nike = initializeTextView(R.id.Nike, Helvetica);
    final TextView Puma = initializeTextView(R.id.Puma, Helvetica);
    final TextView Adidas = initializeTextView(R.id.Adidas, Helvetica);
    final TextView Reebok = initializeTextView(R.id.Reebok, Helvetica);
    final TextView Umbro = initializeTextView(R.id.Umbro, Helvetica);

}

private TextView initializeTextView(int textViewId, Typeface typeface) {
    TextView textView = (TextView)findViewById(textViewId);
    if (textView != null)
        textView.setTypeface(typeface);
    else
        Log.e(TAG, "some error message");
    return textView;
}

Answer 2

您可以存储 int ID 而不是字符串。

//String[] HelveticaTextArray = {"Nike", "Puma", "Adidas", "Reebok", "Umbro"};
int[] HelveticaTextArray = {R.id.Nike, R.id.Puma, R.id.Adidas, R.id.Reebok, R.id.Umbro}


for ( int[] HelveticaTextArray : item ) {
    final TextView HelveticaText = (TextView)findViewById(item);
    HelveticaText.setTypeface(Helvetica);
};

除非您永远不会对这些 TextView 做任何事情，否则我建议您不要这样做。 findViewByID() 是一个相对昂贵的调用，如果您稍后需要使用 TextView 引用，您应该保留它们而不是多次调用 findViewById()

最好用 HelveticaTextView 之类的子类继承 TextView 并在构造函数中设置字体，然后使用它代替 TextView，这样您就不必在 Activity 中弄乱字体了。

类似这样的：

public class HelveticaTextView extends TextView{
    public HelveticaTextView(Context c){
        Typeface Helvetica = Typeface.createFromAsset(c.getAssets(), "fonts/Helvetica.otf");
        super(c);
        this.setTypeface(Helvetica);
    }
    public HelveticaTextView(Context c, AttributeSet attrs){
    Typeface Helvetica = Typeface.createFromAsset(c.getAssets(), "fonts/Helvetica.otf");
        super(c, attrs);
        this.setTypeface(Helvetica);
    }
    public HelveticaTextView(Context context, AttributeSet attrs, int defStyle) {
    Typeface Helvetica = Typeface.createFromAsset(c.getAssets(), "fonts/Helvetica.otf");
        super(c, attrs, defStyle);
        this.setTypeface(Helvetica);
    }
}

然后在您的 xml 布局中更改

<TextView .../>

到

<com.your.package.name.HelveticaTextView .../>

Answer 3

int[] HelveticaArray = {R.id.Nike, R.id.Puma, R.id.Reebok, R.id.Umbro};

for (int item : HelveticaArray) {
    ((TextView).findViewById(item)).setTypeFace(Helvetica);
}

Answer 4

大概是这样的：

TextView[] textViews = { (TextView) findViewById(R.id.Nike), (TextView) findViewById(R.id.Puma) };

for (TextView view : textViews) {
   view.setTypeface(Helvetica);
}