年前的這幾天幢尚,一直在看代碼,發(fā)現(xiàn)自己之前對很多技術(shù)點(diǎn)的理解都不全面蕉鸳,甚至根本就是想當(dāng)然乎赴。所以有這樣一個想法,要把之前理解很粗淺的東西慢慢整理一遍潮尝,補(bǔ)一下技術(shù)上的短板榕吼。
這個過程會比較長,準(zhǔn)備把涉及到的不同技術(shù)點(diǎn)寫一個系列文章衍锚,系列名字嘛友题,就直白點(diǎn):其實(shí)你不懂,是不是很直白O(∩_∩)O~
其實(shí)你不懂:Android之Spanned flag就作為'其實(shí)你不懂'系列的開篇戴质!
1:Spanned flag都有哪些可選值
- SPAN_POINT_MARK_MASK
- SPAN_MARK_MARK
- SPAN_MARK_POINT
- SPAN_POINT_MARK
- SPAN_POINT_POINT
- SPAN_PARAGRAPH
- SPAN_PARAGRAPH
- SPAN_INCLUSIVE_EXCLUSIVE(常用)
- SPAN_INCLUSIVE_INCLUSIVE(常用)
- SPAN_EXCLUSIVE_EXCLUSIVE(常用)
- SPAN_EXCLUSIVE_INCLUSIVE(常用)
- SPAN_COMPOSING
- SPAN_INTERMEDIATE
- SPAN_USER_SHIFT
- SPAN_USER
- SPAN_PRIORITY_SHIFT
- SPAN_PRIORITY
2:Spanned flag常用值的效果
- SPAN_INCLUSIVE_INCLUSIVE
- 前后都包括度宦,在指定范圍前后插入新字符,都會應(yīng)用新樣式
- SPAN_EXCLUSIVE_EXCLUSIVE
- 前后都不包括告匠,在指定范圍前后插入新字符戈抄,樣式無變化
- SPAN_INCLUSIVE_EXCLUSIVE
- 前面包括,后面不包括
- SPAN_EXCLUSIVE_INCLUSIVE
- 后面包括后专,前面不包括
3:不同的值flag划鸽,當(dāng)EditText文本內(nèi)容發(fā)生改變,表現(xiàn)有何區(qū)別戚哎?(不包含SPAN_POINT_MARK_MASK裸诽,SPAN_PARAGRAPH)
實(shí)驗(yàn)初始設(shè)置:不同的EditText初始的文本都是"一二三四五六七八九十"構(gòu)造的SpannableString,都使用相同的AbsoluteSizeSpan型凳,F(xiàn)oregroundColorSpan實(shí)例設(shè)置文本樣式丈冬,區(qū)別只在于flag的值。
//設(shè)置初始內(nèi)容
String str = "一二三四五六七八九十";
//1:構(gòu)造SpannableString實(shí)例
SpannableString spannableStringEE = new SpannableString(str);
SpannableString spannableStringII = new SpannableString(str);
SpannableString spannableStringEI = new SpannableString(str);
SpannableString spannableStringIE = new SpannableString(str);
//2:構(gòu)造指定類型的Span,這里使用AbsoluteSizeSpan,ForegroundColorSpan
AbsoluteSizeSpan sizeSpan = new AbsoluteSizeSpan(24,true);
ForegroundColorSpan colorSpan = new ForegroundColorSpan(Color.RED);
//3:將構(gòu)造的AbsoluteSizeSpan實(shí)例,ForegroundColorSpan實(shí)例應(yīng)用于SpannableString實(shí)例甘畅,只有 flags 有區(qū)別
不同的EditText實(shí)例埂蕊,初始內(nèi)容如下:
3.1:向EditText中繼續(xù)插入文字:
通過圖片可以得到結(jié)論,單純插入文字:
SPAN_POINT_MARK 作用等同于 SPAN_INCLUSIVE_INCLUSIVE疏唾;
SPAN_POINT_MARK 作用等同于 SPAN_EXCLUSIVE_EXCLUSIVE蓄氧;
SPAN_POINT_POINT 作用等同于 SPAN_EXCLUSIVE_INCLUSIVE;
SPAN_COMPOSING 關(guān)聯(lián)的EditText中所有內(nèi)容都失去新樣式槐脏;
其余flag值作用等同于 SPAN_INCLUSIVE_EXCLUSIVE喉童;
3.2:將EditText中內(nèi)容完全刪除后重新輸入:
看GIF動圖可能表述的更清晰。
通過圖片可以得到結(jié)論顿天,內(nèi)容完全刪除后重新輸入:
SPAN_POINT_MARK 和 SPAN_INCLUSIVE_INCLUSIVE 關(guān)聯(lián)的EditText中所有內(nèi)容都會保持新樣式泄朴;
其余所有的flag值重抖,都會失去新樣式;
3.3:按照EditText中新樣式的起止值祖灰,進(jìn)行文字替換:
通過圖片可以得到結(jié)論钟沛,按照EditText中新樣式的起止值,進(jìn)行文字替換:
SPAN_COMPOSING 關(guān)聯(lián)的EditText中所有內(nèi)容都失去新樣式局扶;
其余任意flag關(guān)聯(lián)的EditText,替換來的文字都保持了新樣式恨统;
3.4:新替換文字的起止值范圍大于EditText中新樣式的起止值,進(jìn)行文字替換:
通過圖片可以得到結(jié)論三妈,新替換文字的起止值范圍大于EditText中新樣式的起止值畜埋,進(jìn)行文字替換:
SPAN_POINT_MARK 和 SPAN_INCLUSIVE_INCLUSIVE 關(guān)聯(lián)的EditText,新替換文字會保持新樣式畴蒲;
其余所有的flag值悠鞍,都會失去新樣式;
4:SPAN_POINT_MARK_MASK模燥,SPAN_PARAGRAPH咖祭,當(dāng)EditText文本內(nèi)容發(fā)生改變,表現(xiàn)有何區(qū)別蔫骂?
4.1:為什么這兩個flag值的表現(xiàn)要單獨(dú)分析么翰?
我在實(shí)驗(yàn)過程中,出現(xiàn)過2個異常辽旋,描述如下:
PARAGRAPH span must start at paragraph boundary
PARAGRAPH span must end at paragraph boundary
后來看了SDK中這兩個flag值的描述浩嫌,在java代碼中進(jìn)行實(shí)驗(yàn),理解了這兩個flag值使用的特殊條件:
- start值必須為 0(SpannableString的開頭)或 \n(換行符)所在的索引值+1补胚;
- end必須要為 \n(換行符)所在的索引值+1 或 SpannableString的結(jié)尾字符索引值+1(SpannableString的長度值)
- start值有誤 :報(bào)異常 PARAGRAPH span must start at paragraph boundary
- end值有誤 :報(bào)異常 PARAGRAPH span must end at paragraph boundary
- 同樣码耐,要是start<0或者end>=length,也會報(bào)錯。
怎么理解呢溶其?就是這兩個flag值骚腥,對于新樣式的設(shè)定,是針對于“段落”的握联,何為“段落”桦沉?就是EditText中1:所有的文本或者2:完整的1行或者多行每瞒。如果你在調(diào)用SpannableString的setSpan方法時候金闽,start和end的值所指定的文本不屬于1:所有的文本或者2:完整的1行或者多行,那么就會報(bào)上面提到的異常剿骨。
setSpan(Object what, int start, int end, int flags))]
此處的‘行’代芜,指的是\n(換行符)引起的換行;
看了下面的實(shí)際演示浓利,應(yīng)該更容易理解挤庇。
4.2:EditText中的文本钞速,完全刪除后重新輸入
通過圖片可以得到結(jié)論,EditText中的文本嫡秕,完全刪除后重新輸入:
新輸入的文本未使用新樣式渴语;
4.3:在EditText實(shí)例新樣式的左側(cè),進(jìn)行不完全的替換
通過圖片可以得到結(jié)論昆咽,在EditText實(shí)例新樣式的左側(cè)驾凶,進(jìn)行不完全的替換:
替換的文字所涉及到的完整的的新樣式丟失;
替換的文字沒有涉及到的完整行掷酗,新樣式依然保留调违;
4.4:在EditText實(shí)例新樣式的右側(cè),進(jìn)行不完全的替換
通過圖片可以得到結(jié)論泻轰,在EditText實(shí)例新樣式的右側(cè)技肩,進(jìn)行不完全的替換:
替換文字起始位置所在的完整行,新樣式依然保留浮声,
且
新樣式一直到延伸到替換文字終止位置所在的完整行虚婿;
5:涉及到的代碼
java文件:
public class SpannedActivity extends AppCompatActivity implements View.OnClickListener{
private ScrollView activitySpanned;
// private EditText tvSpanExclusiveExclusive;
// private EditText tvSpanInclusiveInclusive;
// private EditText tvSpanExclusiveInclusive;
// private EditText tvSpanInclusiveExclusive;
private EditText tv_span_point_mark_mask;
// private EditText tv_span_mark_mark;
// private EditText tv_span_mark_point;
// private EditText tv_span_point_mark;
// private EditText tv_span_point_point;
private EditText tv_span_paragraph;
// private EditText tv_span_composing;
// private EditText tv_span_intermediate;
// private EditText tv_span_user_shift;
// private EditText tv_span_user;
// private EditText tv_span_priority_shift;
// private EditText tv_span_priority;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_spanned);
initViews();
}
private void initViews() {
activitySpanned = (ScrollView) findViewById(R.id.activity_spanned);
// tvSpanExclusiveExclusive = (EditText)findViewById(R.id.tv_span_exclusive_exclusive);
// tvSpanInclusiveInclusive = (EditText) findViewById(R.id.tv_span_inclusive_inclusive);
// tvSpanExclusiveInclusive = (EditText) findViewById(R.id.tv_span_exclusive_inclusive);
// tvSpanInclusiveExclusive = (EditText) findViewById(R.id.tv_span_inclusive_exclusive);
tv_span_point_mark_mask = (EditText) findViewById(R.id.tv_span_point_mark_mask);
// tv_span_mark_mark = (EditText) findViewById(R.id.tv_span_mark_mark);
// tv_span_mark_point = (EditText) findViewById(R.id.tv_span_mark_point);
// tv_span_point_mark = (EditText) findViewById(R.id.tv_span_point_mark);
// tv_span_point_point = (EditText) findViewById(R.id.tv_span_point_point);
tv_span_paragraph = (EditText) findViewById(R.id.tv_span_paragraph);
// tv_span_composing = (EditText) findViewById(R.id.tv_span_composing);
// tv_span_intermediate = (EditText) findViewById(R.id.tv_span_intermediate);
// tv_span_user_shift = (EditText) findViewById(R.id.tv_span_user_shift);
// tv_span_user = (EditText) findViewById(R.id.tv_span_user);
// tv_span_priority_shift = (EditText) findViewById(R.id.tv_span_priority_shift);
// tv_span_priority = (EditText) findViewById(R.id.tv_span_priority);
//設(shè)置初始內(nèi)容
String str = "一二三四五六七八九十";
//1:構(gòu)造SpannableString實(shí)例
SpannableString spannableStringEE = new SpannableString(str);
SpannableString spannableStringII = new SpannableString(str);
SpannableString spannableStringEI = new SpannableString(str);
SpannableString spannableStringIE = new SpannableString(str);
//2:構(gòu)造指定類型的Span,這里使用 AbsoluteSizeSpan,ForegroundColorSpan
AbsoluteSizeSpan sizeSpan = new AbsoluteSizeSpan(24,true);
ForegroundColorSpan colorSpan = new ForegroundColorSpan(Color.RED);
//3:將構(gòu)造的AbsoluteSizeSpan實(shí)例,ForegroundColorSpan實(shí)例應(yīng)用于SpannableString實(shí)例,只有 flags 有區(qū)別
/**
{@link SpannableString#setSpan(Object, int, int, int)}
*/
spannableStringEE.setSpan(sizeSpan,2,4, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
spannableStringII.setSpan(sizeSpan,2,4, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
spannableStringEI.setSpan(sizeSpan,2,4, Spanned.SPAN_EXCLUSIVE_INCLUSIVE);
spannableStringIE.setSpan(sizeSpan,2,4, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
spannableStringEE.setSpan(colorSpan,2,4, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
spannableStringII.setSpan(colorSpan,2,4, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
spannableStringEI.setSpan(colorSpan,2,4, Spanned.SPAN_EXCLUSIVE_INCLUSIVE);
spannableStringIE.setSpan(colorSpan,2,4, Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
//4:將SpannableString實(shí)例應(yīng)用于對應(yīng)的EditText實(shí)例
// tvSpanExclusiveExclusive.setText(spannableStringEE);
// tvSpanInclusiveInclusive.setText(spannableStringII);
// tvSpanExclusiveInclusive.setText(spannableStringEI);
// tvSpanInclusiveExclusive.setText(spannableStringIE);
SpannableString spannableStringPMM = new SpannableString("一二三四五六七八九十\n一二三四五六七八九十\n一二三四五六七八九十\n一二三四五六七八九十\n一二三四五六七八九十");
spannableStringPMM.setSpan(sizeSpan,11,33, Spanned.SPAN_POINT_MARK_MASK);
spannableStringPMM.setSpan(colorSpan,11,33, Spanned.SPAN_POINT_MARK_MASK);
tv_span_point_mark_mask.setText(spannableStringPMM);
SpannableString spannableStringMM = new SpannableString(str);
spannableStringMM.setSpan(sizeSpan,2,4, Spanned.SPAN_MARK_MARK);
spannableStringMM.setSpan(colorSpan,2,4, Spanned.SPAN_MARK_MARK);
// tv_span_mark_mark.setText(spannableStringMM);
SpannableString spannableStringMP = new SpannableString(str);
spannableStringMP.setSpan(sizeSpan,2,4, Spanned.SPAN_MARK_POINT);
spannableStringMP.setSpan(colorSpan,2,4, Spanned.SPAN_MARK_POINT);
// tv_span_mark_point.setText(spannableStringMP);
SpannableString spannableStringPM = new SpannableString(str);
spannableStringPM.setSpan(sizeSpan,2,4, Spanned.SPAN_POINT_MARK);
spannableStringPM.setSpan(colorSpan,2,4, Spanned.SPAN_POINT_MARK);
// tv_span_point_mark.setText(spannableStringPM);
SpannableString spannableStringPP = new SpannableString(str);
spannableStringPP.setSpan(sizeSpan,2,4, Spanned.SPAN_POINT_POINT);
spannableStringPP.setSpan(colorSpan,2,4, Spanned.SPAN_POINT_POINT);
// tv_span_point_point.setText(spannableStringPP);
SpannableString spannableStringParagraph = new SpannableString("一二三四五六七八九十\n一二三四五六七八九十\n一二三四五六七八九十\n一二三四五六七八九十\n一二三四五六七八九十");
spannableStringParagraph.setSpan(sizeSpan,11,33, Spanned.SPAN_PARAGRAPH);
spannableStringParagraph.setSpan(colorSpan,11,33, Spanned.SPAN_PARAGRAPH);
tv_span_paragraph.setText(spannableStringParagraph);
SpannableString spannableStringComposing = new SpannableString(str);
spannableStringComposing.setSpan(sizeSpan,2,4, Spanned.SPAN_COMPOSING);
spannableStringComposing.setSpan(colorSpan,2,4, Spanned.SPAN_COMPOSING);
// tv_span_composing.setText(spannableStringComposing);
SpannableString spannableStringIntermediate = new SpannableString(str);
spannableStringIntermediate.setSpan(sizeSpan,2,4, Spanned.SPAN_INTERMEDIATE);
spannableStringIntermediate.setSpan(colorSpan,2,4, Spanned.SPAN_INTERMEDIATE);
// tv_span_intermediate.setText(spannableStringIntermediate);
SpannableString spannableStringUserShift = new SpannableString(str);
spannableStringUserShift.setSpan(sizeSpan,2,4, Spanned.SPAN_USER_SHIFT);
spannableStringUserShift.setSpan(colorSpan,2,4, Spanned.SPAN_USER_SHIFT);
// tv_span_user_shift.setText(spannableStringUserShift);
SpannableString spannableStringUser = new SpannableString(str);
spannableStringUser.setSpan(sizeSpan,2,4, Spanned.SPAN_USER);
spannableStringUser.setSpan(colorSpan,2,4, Spanned.SPAN_USER);
// tv_span_user.setText(spannableStringUser);
SpannableString spannableStringPriorityShift = new SpannableString(str);
spannableStringPriorityShift.setSpan(sizeSpan,2,4, Spanned.SPAN_PRIORITY_SHIFT);
spannableStringPriorityShift.setSpan(colorSpan,2,4, Spanned.SPAN_PRIORITY_SHIFT);
// tv_span_priority_shift.setText(spannableStringPriorityShift);
SpannableString spannableStringPriority = new SpannableString(str);
spannableStringPriority.setSpan(sizeSpan,2,4, Spanned.SPAN_PRIORITY);
spannableStringPriority.setSpan(colorSpan,2,4, Spanned.SPAN_PRIORITY);
// tv_span_priority.setText(spannableStringPriority);
}
@Override
public void onClick(View view) {
switch (view.getId()) {
default:
break;
}
}
}
xml文件:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_spanned"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.jet.coordbehsnack.SpannedActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<!--
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_EXCLUSIVE_EXCLUSIVE" />
<EditText
android:id="@+id/tv_span_exclusive_exclusive"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_EXCLUSIVE_EXCLUSIVE" />
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_INCLUSIVE_INCLUSIVE" />
<EditText
android:id="@+id/tv_span_inclusive_inclusive"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_INCLUSIVE_INCLUSIVE" />
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_EXCLUSIVE_INCLUSIVE" />
<EditText
android:id="@+id/tv_span_exclusive_inclusive"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_EXCLUSIVE_INCLUSIVE" />
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_INCLUSIVE_EXCLUSIVE" />
<EditText
android:id="@+id/tv_span_inclusive_exclusive"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_INCLUSIVE_EXCLUSIVE" />
-->
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_POINT_MARK_MASK" />
<EditText
android:id="@+id/tv_span_point_mark_mask"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_POINT_MARK_MASK" />
<!--
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_MARK_MARK" />
<EditText
android:id="@+id/tv_span_mark_mark"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_MARK_MARK" />
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_MARK_POINT" />
<EditText
android:id="@+id/tv_span_mark_point"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_MARK_POINT" />
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_POINT_MARK" />
<EditText
android:id="@+id/tv_span_point_mark"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_POINT_MARK" />
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_POINT_POINT" />
<EditText
android:id="@+id/tv_span_point_point"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_POINT_POINT" />
-->
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_PARAGRAPH" />
<EditText
android:id="@+id/tv_span_paragraph"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_PARAGRAPH" />
<!--
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_COMPOSING" />
<EditText
android:id="@+id/tv_span_composing"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_COMPOSING" />
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_INTERMEDIATE" />
<EditText
android:id="@+id/tv_span_intermediate"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_INTERMEDIATE" />
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_USER_SHIFT" />
<EditText
android:id="@+id/tv_span_user_shift"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_USER_SHIFT" />
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_USER" />
<EditText
android:id="@+id/tv_span_user"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_USER" />
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_PRIORITY_SHIFT" />
<EditText
android:id="@+id/tv_span_priority_shift"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_PRIORITY_SHIFT" />
<TextView android:textColor="@android:color/black"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="SPAN_PRIORITY" />
<EditText
android:id="@+id/tv_span_priority"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="SPAN_PRIORITY" />
-->
</LinearLayout>
</ScrollView>
以上就是個人實(shí)驗(yàn)和分析的一點(diǎn)結(jié)果阿蝶,若有錯誤雳锋,請各位同學(xué)留言告知!
希望能給大家一點(diǎn)點(diǎn)的收獲!也希望‘其實(shí)你不懂’系列文章真的可以寫完并得到大家的指教和喜歡羡洁!
That's all !