不同的提示字体样式和输入文本字体样式在安卓系统中。

Question

我希望在EditText中为提示信息和输入的文本使用不同的字体样式。 例如，假设提示信息的字体大小为12，普通类型。但是当用户开始在EditText中输入文本时，输入的文本字体大小应该变成14并且加粗。如果用户删除文本，则提示信息应该保持上述类型。

- Pritesh Shah

Answer 1

您可以使用以下代码编程更改提示颜色，使其与在编辑文本中键入的字体样式不同。

    editTextId.setHintTextColor(Color.alpha(006666));

- user1265658

Answer 2

你可以使用 SpannableString 和 MetricAffectingSpan 来实现它。你将能够改变提示的字体、大小和样式。 1) 创建一个自定义的 Hint 对象：

import android.graphics.Typeface;
import android.text.SpannableString;
import android.text.Spanned;
import android.text.style.MetricAffectingSpan;

public class CustomHint extends SpannableString
{
    public CustomHint(final CharSequence source, final int style)
    {
        this(null, source, style, null);
    }

    public CustomHint(final CharSequence source, final Float size)
    {
        this(null, source, size);
    }

    public CustomHint(final CharSequence source, final int style, final Float size)
    {
        this(null, source, style, size);
    }

    public CustomHint(final Typeface typeface, final CharSequence source, final int style)
    {
        this(typeface, source, style, null);
    }

    public CustomHint(final Typeface typeface, final CharSequence source, final Float size)
    {
        this(typeface, source, null, size);
    }

    public CustomHint(final Typeface typeface, final CharSequence source, final Integer style, final Float size)
    {
        super(source);

        MetricAffectingSpan typefaceSpan = new CustomMetricAffectingSpan(typeface, style, size);
        setSpan(typefaceSpan, 0, source.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
    }
}

2) 创建自定义的 MetricAffectingSpan 对象：

import android.graphics.Typeface;
import android.text.TextPaint;
import android.text.style.MetricAffectingSpan;

public class CustomMetricAffectingSpan extends MetricAffectingSpan
{
    private final Typeface _typeface;
    private final Float    _newSize;
    private final Integer  _newStyle;

    public CustomMetricAffectingSpan(Float size)
    {
        this(null, null, size);
    }

    public CustomMetricAffectingSpan(Float size, Integer style)
    {
        this(null, style, size);
    }

    public CustomMetricAffectingSpan(Typeface type, Integer style, Float size)
    {
        this._typeface = type;
        this._newStyle = style;
        this._newSize = size;
    }

    @Override
    public void updateDrawState(TextPaint ds)
    {
        applyNewSize(ds);
    }

    @Override
    public void updateMeasureState(TextPaint paint)
    {
        applyNewSize(paint);
    }

    private void applyNewSize(TextPaint paint)
    {
        if (this._newStyle != null)
            paint.setTypeface(Typeface.create(this._typeface, this._newStyle));
        else
            paint.setTypeface(this._typeface);

        if (this._newSize != null)
            paint.setTextSize(this._newSize);
    }
}

3) 使用：

Typeface newTypeface = Typeface.createFromAsset(getAssets(), "AguafinaScript-Regular.ttf");
CustomHint customHint = new CustomHint(newTypeface, "Enter some text", Typeface.BOLD_ITALIC, 60f);
        //        CustomHint customHint = new CustomHint(newTypeface, "Enter some text", Typeface.BOLD_ITALIC);
        //        CustomHint customHint = new CustomHint(newTypeface, "Enter some text", 60f);
        //        CustomHint customHint = new CustomHint("Enter some text", Typeface.BOLD_ITALIC, 60f);
        //        CustomHint customHint = new CustomHint("Enter some text", Typeface.BOLD_ITALIC);
        //        CustomHint customHint = new CustomHint("Enter some text", 60f);

customEditText.setHint(customHint);

- Ayaz Alifov

Answer 3

已经给出的答案是正确的，但是目前也可以通过 XML 文件中的 android:textColorHint 属性指定不同的颜色。例如，您可以像这样做（假设您已经正确地将 my_favourite_colour 定义为资源）：

<EditText
... other properties here ...
android:textColorHint="@color/my_favourite_colour"
</EditText>

- elbuild