[[["容易理解","easyToUnderstand","thumb-up"],["確實解決了我的問題","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["缺少我需要的資訊","missingTheInformationINeed","thumb-down"],["過於複雜/步驟過多","tooComplicatedTooManySteps","thumb-down"],["過時","outOfDate","thumb-down"],["翻譯問題","translationIssue","thumb-down"],["示例/程式碼問題","samplesCodeIssue","thumb-down"],["其他","otherDown","thumb-down"]],[],[],[],null,["# Make apps more accessible\n\nTry to make your Android app usable for everyone, including people with\naccessibility needs.\n\nPeople with impaired vision, color blindness, impaired hearing, impaired\ndexterity, cognitive disabilities, and many other disabilities use Android\ndevices. When you develop apps with\naccessibility in mind, you make the user experience better for people with\naccessibility needs.\n\nThis page presents guidelines for implementing key elements of accessibility\nso that everyone can use your app more easily. For more in-depth guidance on\nhow to make your app more accessible, see [Principles for improving app\naccessibility](/guide/topics/ui/accessibility/principles).\n\nIncrease text visibility\n------------------------\n\nFor each set of text within your app, we recommend the *color contrast*---or\ndifference in perceived brightness between the color of the text and the color\nof the background behind the text---to be above a specific threshold. The\nexact threshold depends on the text's font size and whether the text appears in\nbold:\n\n- If the text is smaller than 18pt, or if the text is bold and smaller than 14pt, set the color contrast ratio to at least 4.5:1.\n- For all other text, set the color contrast ratio to at least 3:1.\n\nThe following image shows two examples of text-to-background color contrast: \n**Figure 1.** Lower than recommended (left) and sufficient (right) color contrast.\n\nTo check the text-to-background color contrast in your app, use an online color\ncontrast checker or the [Accessibility\nScanner](https://play.google.com/store/apps/details?id=com.google.android.apps.accessibility.auditor)\napp.\n\nUse large, simple controls\n--------------------------\n\nYour app's UI is easier to use if its controls are easier to see\nand tap. We recommend that each interactive UI element have a focusable area, or\n*touch target size*, of at least 48dpx48dp. Larger is even better.\n\nFor a given UI element to have a large enough touch target size, the following\nconditions should **both** be true:\n\n- The sum of the values of [`android:paddingLeft`](/reference/android/view/View#attr_android:paddingLeft), [`android:minWidth`](/reference/android/view/View#attr_android:minWidth), and [`android:paddingRight`](/reference/android/view/View#attr_android:paddingRight) is greater than or equal to 48dp.\n- The sum of the values of [`android:paddingTop`](/reference/android/view/View#attr_android:paddingTop), [`android:minHeight`](/reference/android/view/View#attr_android:minHeight), and [`android:paddingBottom`](/reference/android/view/View#attr_android:paddingBottom) is greater than or equal to 48dp.\n\nThe padding values allow an object's *visible* size to be less than 48dpx48dp\nwhile still having the recommended touch target size.\n\nThe following code snippet shows an element that has the recommended touch\ntarget size: \n\n```xml\n\u003cImageButton ...\n android:paddingLeft=\"4dp\"\n android:minWidth=\"40dp\"\n android:paddingRight=\"4dp\"\n\n android:paddingTop=\"8dp\"\n android:minHeight=\"32dp\"\n android:paddingBottom=\"8dp\" /\u003e\n```\n\nDescribe each UI element\n------------------------\n\nFor each UI element in your app, include a description that\ndescribes the element's purpose. In most cases, you include this description in\nthe element's `contentDescription` attribute, as shown in the following code\nsnippet: \n\n```xml\n\u003c!-- Use string resources for easier localization. --\u003e\n\u003c!-- The en-US value for the following string is \"Inspect\". --\u003e\n\u003cImageView\n ...\n android:contentDescription=\"@string/inspect\" /\u003e\n```\n| **Note:** Don't provide descriptions for [`TextView`](/reference/android/widget/TextView) elements. Android accessibility services automatically announce the text itself as the description.\n\nWhen adding descriptions to your app's UI elements, keep the following best\npractices in mind:\n\n- Don't include the type of UI element in the content description. Screen\n readers automatically announce both the element's type and description. For\n example, if selecting a button causes a \"submit\" action to occur in your app,\n make the button's description `\"Submit\"`, not `\"Submit button\"`.\n\n- Each description must be unique. That way, when screen reader users\n encounter a repeated element description, they correctly recognize that the\n focus is on an element that already had focus earlier. In particular, each item\n within a view group such as\n [`RecyclerView`](/reference/androidx/recyclerview/widget/RecyclerView) must have\n a different description. Each description must reflect the content that's unique\n to a given item, such as the name of a city in a list of locations.\n\n- If your app's `minSdkVersion` is `16` or higher, you can set the\n [`android:importantForAccessibility`](/reference/android/view/View#attr_android:importantForAccessibility)\n attribute to `\"no\"` for graphical elements that are only used for decorative\n effect.\n\nAdditional resources\n--------------------\n\nTo learn more about making your app more accessible, see the following\nadditional resources:\n\n### Codelabs\n\n- [Starting Android\n Accessibility](https://codelabs.developers.google.com/codelabs/starting-android-accessibility)\n\n### Blog posts\n\n- [Accessibility: Are You Serving All Your\n Users?](https://android-developers.googleblog.com/2012/04/accessibility-are-you-serving-all-your.html)"]]
