{"id":584,"date":"2023-02-22T17:55:03","date_gmt":"2023-02-22T09:55:03","guid":{"rendered":"https:\/\/iichen.cn\/?p=584"},"modified":"2025-01-23T16:11:32","modified_gmt":"2025-01-23T08:11:32","slug":"android-drawtext%e8%af%a6%e8%a7%a3","status":"publish","type":"post","link":"https:\/\/iichen.cn\/?p=584","title":{"rendered":"Android-DrawText\u8be6\u89e3"},"content":{"rendered":"

1. \u5355\u884c\u6587\u672c<\/h3>\n

\"\"<\/div><\/p>\n

FontMetrics.ascent \u6216 Paint.ascent \u6ce8\u610f\u8fd9\u4e9b\u90fd\u662f\u95f4\u8ddd<\/strong><\/p>\n

ascent = ascent\u7ebf\u7684y\u5750\u6807 - baseline\u7ebf\u7684y\u5750\u6807\uff1b   \/\/ \u4e3a\u8d1f\u503c\ndescent = descent\u7ebf\u7684y\u5750\u6807 - baseline\u7ebf\u7684y\u5750\u6807\uff1b\ntop = top\u7ebf\u7684y\u5750\u6807 - baseline\u7ebf\u7684y\u5750\u6807\uff1b\nbottom = bottom\u7ebf\u7684y\u5750\u6807 - baseline\u7ebf\u7684y\u5750\u6807\uff1b\n<\/code><\/pre>\n
center\u5148\u8ba1\u7b97<\/strong><\/p>\n
float centerY\n= (fontmetrics.descent - fontmetrics.ascent) \/ 2 - fontmetrics.descent;\n= -fontmetrics.ascent \/ 2 - fontmetrics.descent \/ 2;\n= -(fontmetrics.ascent + fontmetrics.descent) \/ 2;\n= math.abs(fontmetrics.ascent + fontmetrics.descent) \/ 2;\n<\/code><\/pre>\n
canvas.drawText(text, x, y – ((paint.descent() + paint.ascent()) \/ 2), paint);<\/strong><\/p>\n
public void draw(canvas canvas) {\n super.draw(canvas);\n \/\/ \u5c06\u5750\u6807\u539f\u70b9\u79fb\u5230\u63a7\u4ef6\u4e2d\u5fc3\n canvas.translate(getwidth() \/ 2, getheight() \/ 2);\n \/\/ x\u8f74\n canvas.drawline(-getwidth() \/ 2, 0, getwidth() \/ 2, 0, paint);\n \/\/ y\u8f74\n canvas.drawline(0, -getheight() \/ 2, 0, getheight() \/ 2, paint);\n\n \/\/ \u7ed8\u5236\u5c45\u4e2d\u6587\u5b57\n paint.settextsize(sp2px(50));\n paint.setcolor(color.gray);\n \/\/ \u6587\u5b57\u5bbd\n float textwidth = paint.measuretext(\"yangle'blog\");\n \/\/ \u6587\u5b57baseline\u5728y\u8f74\u65b9\u5411\u7684\u4f4d\u7f6e\n float baseliney = math.abs(paint.ascent() + paint.descent()) \/ 2;\n canvas.drawtext(\"yangle'blog\", -textwidth \/ 2, baseliney, paint);\n}\n<\/code><\/pre>\n
2. \u591a\u884c\u6587\u672c<\/h3>\n
\"\"<\/div>
\n– \u6587\u672c\u5728x\u8f74\u4e0a\u65b9\uff1a\u7ea2\u8272a\u7684baseline\u5411\u4e0a\u79fb\u52a8a\u8ddd\u79bb\uff0c\u603b\u9ad8\u5ea6\u7684\/2 – \u6587\u672c\u7684top\u503c\uff08\u7edd\u5bf9\u503c\uff09
\n– \u6587\u672c\u5728x\u8f74\u4e2d\u95f4\uff1a\u7ea2\u8272a\u7684baseline\u5411\u4e0b\u79fb\u52a8b\u8ddd\u79bb\uff0c\u8ba1\u7b97\u516c\u5f0f\u8bf7\u53c2\u8003\u5355\u884c\u6587\u672c\u5c45\u4e2d\u516c\u5f0f
\n– \u6587\u672c\u5728x\u8f74\u4e0b\u65b9\uff1a\u7ea2\u8272a\u7684baseline\u5411\u4e0b\u79fb\u52a8c\u8ddd\u79bb\uff0c\u603b\u9ad8\u5ea6\u7684\/2 – \u6587\u672c\u7684bottom\u503c\uff08\u7edd\u5bf9\u503c\uff09<\/p>\n
private void drawcentermultitext2(canvas canvas) {\n string[] texts = {\"a\", \"b\", \"c\"};\n\n paint.fontmetrics fontmetrics = paint.getfontmetrics();\n \/\/ top\u7edd\u5bf9\u503c\n float top = math.abs(fontmetrics.top);\n \/\/ ascent\u7edd\u5bf9\u503c\n float ascent = math.abs(fontmetrics.ascent);\n \/\/ descent\uff0c\u6b63\u503c\n float descent = fontmetrics.descent;\n \/\/ bottom\uff0c\u6b63\u503c\n float bottom = fontmetrics.bottom;\n \/\/ \u884c\u6570\n int textlines = texts.length;\n \/\/ \u6587\u672c\u9ad8\u5ea6\n float textheight = top + bottom;\n \/\/ \u6587\u672c\u603b\u9ad8\u5ea6\n float texttotalheight = textheight * textlines;\n \/\/ \u57fa\u6570\n float baseposition = (textlines - 1) \/ 2f;\n\n for (int i = 0; i < textlines; i++) {\n  \/\/ \u6587\u672c\u5bbd\u5ea6\n  float textwidth = paint.measuretext(texts[i]);\n  \/\/ \u6587\u672cbaseline\u5728y\u8f74\u65b9\u5411\u7684\u4f4d\u7f6e\n  float baseliney;\n\n  if (i < baseposition) {\n   \/\/ x\u8f74\u4e0a\uff0c\u503c\u4e3a\u8d1f\n   \/\/ \u603b\u9ad8\u5ea6\u7684\/2 - \u5df2\u7ed8\u5236\u7684\u6587\u672c\u9ad8\u5ea6 - \u6587\u672c\u7684top\u503c\uff08\u7edd\u5bf9\u503c\uff09\n   baseliney = -(texttotalheight \/ 2 - textheight * i - top);\n\n  } else if (i > baseposition) {\n   \/\/ x\u8f74\u4e0b\uff0c\u503c\u4e3a\u6b63\n   \/\/ \u603b\u9ad8\u5ea6\u7684\/2 - \u672a\u7ed8\u5236\u7684\u6587\u672c\u9ad8\u5ea6 - \u6587\u672c\u7684bottom\u503c\uff08\u7edd\u5bf9\u503c\uff09\n   baseliney = texttotalheight \/ 2 - textheight * (textlines - i - 1) - bottom;\n\n  } else {\n   \/\/ x\u8f74\u4e2d\uff0c\u503c\u4e3a\u6b63\n   \/\/ \u8ba1\u7b97\u516c\u5f0f\u8bf7\u53c2\u8003\u5355\u884c\u6587\u672c\u5c45\u4e2d\u516c\u5f0f\n   baseliney = (ascent - descent) \/ 2;\n  }\n\n  canvas.drawtext(texts[i], -textwidth \/ 2, baseliney, paint);\n }\n}\n<\/code><\/pre>\n
\u53c2\u8003<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
1. \u5355\u884c\u6587\u672c FontMetrics.ascent \u6216 Paint.ascent \u6ce8\u610f\u8fd9\u4e9b\u90fd\u662f\u95f4\u8ddd asce […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11,8],"tags":[],"class_list":["post-584","post","type-post","status-publish","format-standard","hentry","category-android","category-8"],"yoast_head":"\nAndroid-DrawText\u8be6\u89e3 - IIchen<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/iichen.cn\/?p=584\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Android-DrawText\u8be6\u89e3 - IIchen\" \/>\n<meta property=\"og:description\" content=\"1. \u5355\u884c\u6587\u672c FontMetrics.ascent \u6216 Paint.ascent \u6ce8\u610f\u8fd9\u4e9b\u90fd\u662f\u95f4\u8ddd asce […]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/iichen.cn\/?p=584\" \/>\n<meta property=\"og:site_name\" content=\"IIchen\" \/>\n<meta property=\"article:published_time\" content=\"2023-02-22T09:55:03+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2025-01-23T08:11:32+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/iichen.cn\/wp-content\/uploads\/2025\/01\/android_text_formatter-300x87.png\" \/>\n<meta name=\"author\" content=\"iichen\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"iichen\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/iichen.cn\/?p=584#article\",\"isPartOf\":{\"@id\":\"https:\/\/iichen.cn\/?p=584\"},\"author\":{\"name\":\"iichen\",\"@id\":\"https:\/\/iichen.cn\/#\/schema\/person\/4a47edf85ab49841df9e8f6aee40b77c\"},\"headline\":\"Android-DrawText\u8be6\u89e3\",\"datePublished\":\"2023-02-22T09:55:03+00:00\",\"dateModified\":\"2025-01-23T08:11:32+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/iichen.cn\/?p=584\"},\"wordCount\":36,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\/\/iichen.cn\/#\/schema\/person\/4a47edf85ab49841df9e8f6aee40b77c\"},\"image\":{\"@id\":\"https:\/\/iichen.cn\/?p=584#primaryimage\"},\"thumbnailUrl\":\"https:\/\/iichen.cn\/wp-content\/uploads\/2025\/01\/android_text_formatter-300x87.png\",\"articleSection\":[\"Android\",\"\u7b14\u8bb0\"],\"inLanguage\":\"zh-Hans\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\/\/iichen.cn\/?p=584#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/iichen.cn\/?p=584\",\"url\":\"https:\/\/iichen.cn\/?p=584\",\"name\":\"Android-DrawText\u8be6\u89e3 - 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