編輯:關於Android編程
今天項目沒什麼進展,公司後台出問題了。看了下剛剛學習Android時的筆記,發現TextView會自動換行,而且排版文字參差不齊。查了下資料,總結原因如下:
1、半角字符與全角字符混亂所致:這種情況一般就是漢字與數字、英文字母混用
解決方法一:
將textview中的字符全角化。即將所有的數字、字母及標點全部轉為全角字符,使它們與漢字同占兩個字節,這樣就可以避免由於占位導致的排版混亂問題了。 半角轉為全角的代碼如下,只需調用即可。
public static String ToDBC(String input) {
char[] c = input.toCharArray();
for (int i = 0; i< c.length; i++) {
if (c[i] == 12288) {
c[i] = (char) 32;
continue;
}if (c[i]> 65280&& c[i]< 65375)
c[i] = (char) (c[i] - 65248);
}
return new String(c);
}
解決方法二:
去除特殊字符或將所有中文標號替換為英文標號。利用正則表達式將所有特殊字符過濾,或利用replaceAll()將中文標號替換為英文標號。則轉化之後,則可解決排版混亂問題。
// 替換、過濾特殊字符
public static String StringFilter(String str) throws PatternSyntaxException{
str=str.replaceAll("【","[").replaceAll("】","]").replaceAll("!","!");//替換中文標號
String regEx="[『』]"; // 清除掉特殊字符
Pattern p = Pattern.compile(regEx);
Matcher m = p.matcher(str);
return m.replaceAll("").trim();
}
2、TextView在顯示中文的時候 標點符號不能顯示在一行的行首和行尾,如果一個標點符號剛好在一行的行尾,該標點符號就會連同前一個字符跳到下一行顯示。
解決方法:在標點符號後加一個空格。
3、一個英文單詞不能被顯示在兩行中( TextView在顯示英文時,標點符號是可以放在行尾的,但英文單詞也不能分開 )。
4、如果要兩行對其的顯示效果:有兩種方法
方法一:
修改Android源代碼;將frameworks/base/core/java/android/text下的StaticLayout.java文件中的如下代碼:
if (c == ' ' || c == '/t' ||
((c == '.' || c == ',' || c == ':' || c == ';') &&
(j - 1 < here || !Character.isDigit(chs[j - 1 - start])) &&
(j + 1 >= next || !Character.isDigit(chs[j + 1 - start]))) ||
((c == '/' || c == '-') &&
(j + 1 >= next || !Character.isDigit(chs[j + 1 - start]))) ||
(c >= FIRST_CJK && isIdeographic(c, true) &&
j + 1 < next && isIdeographic(chs[j + 1 - start], false))) {
okwidth = w;
ok = j + 1;
if (fittop < oktop)
oktop = fittop;
if (fitascent < okascent)
okascent = fitascent;
if (fitdescent > okdescent)
okdescent = fitdescent;
if (fitbottom > okbottom)
okbottom = fitbottom;
}
去掉就可以了。去掉後標點符號可以顯示在行首和行尾,英文單詞也可以被分開在兩行中顯示。
方法二:
自定義View顯示文本
網上就有達人采用自定義View來解決這個問題,我做了實驗並總結了一下:
自定義View的步驟:
1)繼承View類或其子類,例子繼承了TextView類;
2)寫構造函數,通過XML獲取屬性(這一步中可以自定義屬性,見例程);
3)重寫父類的某些函數,一般都是以on開頭的函數,例子中重寫了onDraw()和onMeasure()函數;
=========================CYTextView.java=============================
public class CYTextView extends TextView {
public static int m_iTextHeight; //文本的高度
public static int m_iTextWidth;//文本的寬度
private Paint mPaint = null;
private String string="";
private float LineSpace = 0;//行間距
public CYTextView(Context context, AttributeSet set)
{
super(context,set);
TypedArray typedArray = context.obtainStyledAttributes(set, R.styleable.CYTextView);
int width = typedArray.getInt(R.styleable. CY TextView_textwidth, 320);
float textsize = typedArray.getDimension(R.styleable. CY TextView_textSize, 24);
int textcolor = typedArray.getColor(R.styleable. CY TextView_textColor, -1442840576);
float linespace = typedArray.getDimension(R.styleable. CY TextView_lineSpacingExtra, 15);
int typeface = typedArray.getColor(R.styleable. CY TextView_typeface, 0);
typedArray.recycle();
//設置 CY TextView的寬度和行間距www.linuxidc.com
m_iTextWidth=width;
LineSpace=linespace;
// 構建paint對象
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setColor(textcolor);
mPaint.setTextSize(textsize);
switch(typeface){
case 0:
mPaint.setTypeface(Typeface.DEFAULT);
break;
case 1:
mPaint.setTypeface(Typeface.SANS_SERIF);
break;
case 2:
mPaint.setTypeface(Typeface.SERIF);
break;
case 3:
mPaint.setTypeface(Typeface.MONOSPACE);
break;
default:
mPaint.setTypeface(Typeface.DEFAULT);
break;
}
}
@Override
protected void onDraw(Canvas canvas)
{
super.onDraw(canvas);
char ch;
int w = 0;
int istart = 0;
int m_iFontHeight;
int m_iRealLine=0;
int x=2;
int y=30;
Vector m_String=new Vector();
FontMetrics fm = mPaint.getFontMetrics();
m_iFontHeight = (int) Math.ceil(fm.descent - fm.top) + (int)LineSpace;//計算字體高度(字體高度+行間距)
for (int i = 0; i < string.length(); i++)
{
ch = string.charAt(i);
float[] widths = new float[1];
String srt = String.valueOf(ch);
mPaint.getTextWidths(srt, widths);
if (ch == '/n'){
m_iRealLine++;
m_String.addElement(string.substring(istart, i));
istart = i + 1;
w = 0;
}else{
w += (int) (Math.ceil(widths[0]));
if (w > m_iTextWidth){
m_iRealLine++;
m_String.addElement(string.substring(istart, i));
istart = i;
i--;
w = 0;
}else{
if (i == (string.length() - 1)){
m_iRealLine++;
m_String.addElement(string.substring(istart, string.length()));
}
}
}
}
m_iTextHeight=m_iRealLine*m_iFontHeight+2;
canvas.setViewport(m_iTextWidth, m_iTextWidth);
for (int i = 0, j = 0; i < m_iRealLine; i++, j++)
{
canvas.drawText((String)(m_String.elementAt(i)), x, y+m_iFontHeight * j, mPaint);
}
}
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
int measuredHeight = measureHeight(heightMeasureSpec);
int measuredWidth = measureWidth(widthMeasureSpec);
this.setMeasuredDimension(measuredWidth, measuredHeight);
this.setLayoutParams(new LinearLayout.LayoutParams(measuredWidth,measuredHeight));
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
private int measureHeight(int measureSpec)
{
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
// Default size if no limits are specified.
initHeight();
int result = m_iTextHeight;
if (specMode == MeasureSpec.AT_MOST){
// Calculate the ideal size of your
// control within this maximum size.
// If your control fills the available
// space return the outer bound.
result = specSize;
}else if (specMode == MeasureSpec.EXACTLY){
// If your control can fit within these bounds return that value.
result = specSize;
}
return result;
}
private void initHeight()
{
//設置 CY TextView的初始高度為0
m_iTextHeight=0;
//大概計算 CY TextView所需高度
FontMetrics fm = mPaint.getFontMetrics();
int m_iFontHeight = (int) Math.ceil(fm.descent - fm.top) + (int)LineSpace;
int line=0;
int istart=0;
int w=0;
for (int i = 0; i < string.length(); i++)
{
char ch = string.charAt(i);
float[] widths = new float[1];
String srt = String.valueOf(ch);
mPaint.getTextWidths(srt, widths);
if (ch == '/n'){
line++;
istart = i + 1;
w = 0;
}else{
w += (int) (Math.ceil(widths[0]));
if (w > m_iTextWidth){
line++;
istart = i;
i--;
w = 0;
}else{
if (i == (string.length() - 1)){
line++;
}
}
}
}
m_iTextHeight=(line)*m_iFontHeight+2;
}
private int measureWidth(int measureSpec)
{
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
// Default size if no limits are specified.
int result = 500;
if (specMode == MeasureSpec.AT_MOST){
// Calculate the ideal size of your control
// within this maximum size.
// If your control fills the available space
// return the outer bound.
result = specSize;
}else if (specMode == MeasureSpec.EXACTLY){
// If your control can fit within these bounds return that value.
result = specSize;
}
return result;
}
public void SetText(String text)(注:此函數目前只有在UI線程中調用才可以把文本畫出來,在其它線程中
無法畫文本,找了好久找不到原因,求高手解答)
{
string = text;
// requestLayout();
// invalidate();
}
}
=======================attrs.xml===============================
該文件是自定義的屬性,放在工程的res/values下
=======================main.xml==========================
xmlns:Android="http://schemas.android.com/apk/res/android"
Android:layout_width="320px"
Android:layout_height="320px"
Android:background="#ffffffff"
>
xmlns:Android="http://schemas.android.com/apk/res/android"
Android:orientation="vertical"
Android:layout_width="fill_parent"
Android:layout_height="fill_parent">
xmlns:cy="http://schemas.Android.com/apk/res/ com.cy.CYTextView "
Android:id="@+id/mv"
Android:layout_height="wrap_content"
Android:layout_width="wrap_content"
cy :textwidth="320"
cy :textSize="24sp"
cy :textColor="#aa000000"
cy :lineSpacingExtra="15sp"
cy :typeface="serif">
藍色代碼即為自定義View,其中以cy命名空間開頭的屬性是自定義屬性;
=======================Main.java=============================
public class Main extends Activity {
CYTextView mCYTextView;
String text = "Android提供了精巧和有力的組件化模型構建用戶的UI部分。主要是基於布局類:View和 ViewGroup。在此基礎上,android平台提供了大量的預制的View和xxxViewGroup子 類,即布局(layout)和窗口小部件(widget)。可以用它們構建自己的UI。";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.setContentView(R.layout.main);
mCYTextView = (CYTextView)findViewById(R.id.mv);
mCYTextView.SetText(text);
}
}
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