StaticLayout如何在Android中使用？

概述我需要构建自己的自定义TextView,所以我一直在学习StaticLayout在画布上绘制文本.这比直接使用Canvas.drawText()更好,或者documentation说.但是,文档没有给出任何示例.只有一个含糊的提及StaticLayout.Builder是更新的方式.我找到了一个例子here,但似乎有点过时了.我终于工作了,

我需要构建自己的自定义TextVIEw,所以我一直在学习StaticLayout在画布上绘制文本.这比直接使用Canvas.drawText()更好,或者documentation说.但是,文档没有给出任何示例.只有一个含糊的提及StaticLayout.Builder是更新的方式.

我找到了一个例子here,但似乎有点过时了.

我终于工作了,但是我在下面添加了我的解释.

解决方法:

StaticLayout(similar to DynamicLayout and BoringLayout)用于在画布上布局和绘制文本.它通常用于以下任务：

>测量布局后多行文字的大小.
>在位图图像上绘制文本.
>创建一个处理自己的文本布局的自定义视图(而不是使用嵌入的TextVIEw创建复合视图). TextVIEw本身使用StaticLayout internally.

测量文字大小

单线

如果您只有一行文本,则可以使用Paint或TextPaint进行测量.

String text = "This is some text."TextPaint myTextPaint = new TextPaint();mTextPaint.setAntiAlias(true);mTextPaint.setTextSize(16 * getResources().getdisplayMetrics().density);mTextPaint.setcolor(0xFF000000);float wIDth = mTextPaint.measureText(text);float height = -mTextPaint.ascent() + mTextPaint.descent();

多行

但是,如果有换行并且您需要高度,那么最好使用StaticLayout.您提供宽度,然后您可以从StaticLayout获取高度.

String text = "This is some text. This is some text. This is some text. This is some text. This is some text. This is some text.";TextPaint myTextPaint = new TextPaint();myTextPaint.setAntiAlias(true);myTextPaint.setTextSize(16 * getResources().getdisplayMetrics().density);myTextPaint.setcolor(0xFF000000);int wIDth = 200;Layout.Alignment alignment = Layout.Alignment.AliGN_norMAL;float spacingMultiplIEr = 1;float spacingAddition = 0;boolean includepadding = false;StaticLayout myStaticLayout = new StaticLayout(text, myTextPaint, wIDth, alignment, spacingMultiplIEr, spacingAddition, includepadding);float height = myStaticLayout.getHeight(); 

新API

如果您想使用较新的StaticLayout.Builder(可从API 23获得),您可以获得如下布局：

StaticLayout.Builder builder = StaticLayout.Builder.obtain(text, 0, text.length(), myTextPaint, wIDth);StaticLayout myStaticLayout = builder.build();

您可以使用点表示法来添加额外设置：

StaticLayout.Builder builder = StaticLayout.Builder.obtain(text, 0, text.length(), myTextPaint, wIDth)        .setAlignment(Layout.Alignment.AliGN_norMAL)        .setlinespacing(spacingMultiplIEr, spacingAddition)        .setIncludePad(includepadding)        .setMaxlines(5);StaticLayout myStaticLayout = builder.build();

在图像上写文字

我可能会在将来扩展它,但是现在请参阅this post以获取使用StaticLayout并返回位图的方法的示例.

进行自定义文本处理视图

以下是使用StaticLayout的自定义视图的示例.它的行为类似于简单的TextVIEw.当文本太长而无法放在屏幕上时,它会自动换行并增加其高度.

码

MyVIEw.java

public class MyVIEw extends VIEw {    String mText = "This is some text.";    TextPaint mTextPaint;    StaticLayout mStaticLayout;    // use this constructor if creating MyVIEw programmatically    public MyVIEw(Context context) {        super(context);        initLabelVIEw();    }    // this constructor is used when created from xml    public MyVIEw(Context context, AttributeSet attrs) {        super(context, attrs);        initLabelVIEw();    }    private voID initLabelVIEw() {        mTextPaint = new TextPaint();        mTextPaint.setAntiAlias(true);        mTextPaint.setTextSize(16 * getResources().getdisplayMetrics().density);        mTextPaint.setcolor(0xFF000000);        // default to a single line of text        int wIDth = (int) mTextPaint.measureText(mText);        mStaticLayout = new StaticLayout(mText, mTextPaint, (int) wIDth, Layout.Alignment.AliGN_norMAL, 1.0f, 0, false);        // New API alternate        //        // StaticLayout.Builder builder = StaticLayout.Builder.obtain(mText, 0, mText.length(), mTextPaint, wIDth)        //        .setAlignment(Layout.Alignment.AliGN_norMAL)        //        .setlinespacing(1, 0) // multiplIEr, add        //        .setIncludePad(false);        // mStaticLayout = builder.build();    }    @OverrIDe    protected voID onMeasure(int wIDthMeasureSpec, int heightmeasureSpec) {        // Tell the parent layout how big this vIEw would like to be        // but still respect any requirements (measure specs) that are passed down.        // determine the wIDth        int wIDth;        int wIDthMode = MeasureSpec.getMode(wIDthMeasureSpec);        int wIDthRequirement = MeasureSpec.getSize(wIDthMeasureSpec);        if (wIDthMode == MeasureSpec.EXACTLY) {            wIDth = wIDthRequirement;        } else {            wIDth = mStaticLayout.getWIDth() + getpaddingleft() + getpaddingRight();            if (wIDthMode == MeasureSpec.AT_MOST) {                if (wIDth > wIDthRequirement) {                    wIDth = wIDthRequirement;                    // too long for a single line so relayout as multiline                    mStaticLayout = new StaticLayout(mText, mTextPaint, wIDth, Layout.Alignment.AliGN_norMAL, 1.0f, 0, false);                }            }        }        // determine the height        int height;        int heightmode = MeasureSpec.getMode(heightmeasureSpec);        int heightRequirement = MeasureSpec.getSize(heightmeasureSpec);        if (heightmode == MeasureSpec.EXACTLY) {            height = heightRequirement;        } else {            height = mStaticLayout.getHeight() + getpaddingtop() + getpaddingBottom();            if (heightmode == MeasureSpec.AT_MOST) {                height = Math.min(height, heightRequirement);            }        }        // required call: set wIDth and height        setMeasuredDimension(wIDth, height);    }    @OverrIDe    protected voID onDraw(Canvas canvas) {        super.onDraw(canvas);        // do as little as possible insIDe onDraw to improve performance        // draw the text on the canvas after adjusting for padding        canvas.save();        canvas.translate(getpaddingleft(), getpaddingtop());        mStaticLayout.draw(canvas);        canvas.restore();    }}

activity_main.xml中

<?xml version="1.0" enCoding="utf-8"?><relativeLayout    xmlns:androID="http://schemas.androID.com/apk/res/androID"    xmlns:tools="http://schemas.androID.com/tools"    androID:ID="@+ID/activity_main"    androID:layout_wIDth="match_parent"    androID:layout_height="match_parent"    androID:padding="@dimen/activity_vertical_margin"    tools:context="com.example.layoutpractice.MainActivity">    <com.example.layoutpractice.MyVIEw        androID:layout_centerHorizontal="true"        androID:background="@color/colorAccent"        androID:padding="10dp"        androID:layout_wIDth="wrap_content"        androID:layout_height="wrap_content"/></relativeLayout>

笔记

> This,this和this对于学习如何创建自定义文本处理视图很有用.
>如果要添加可以从代码或xml设置的自定义属性,请参阅Creating a View Class.

总结

以上是内存溢出为你收集整理的StaticLayout如何在Android中使用？全部内容，希望文章能够帮你解决StaticLayout如何在Android中使用？所遇到的程序开发问题。

如果觉得内存溢出网站内容还不错，欢迎将内存溢出网站推荐给程序员好友。