Android 上的 Web 视图缩放WebView Zoom on Android

05/09/2019

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此 Android 平台特定平台支持 "缩小到缩放" 和 "缩放" 控件 WebView 。This Android platform-specific enables pinch-to-zoom and a zoom control on a WebView. 它通过将 WebView.EnableZoomControls 和 WebView.DisplayZoomControls 可绑定属性设置为值，在 XAML 中使用 boolean ：It's consumed in XAML by setting the WebView.EnableZoomControls and WebView.DisplayZoomControls bindable properties to boolean values:

xmlns:android="clr-namespace::::no-loc(Xamarin.Forms):::.PlatformConfiguration.AndroidSpecific;assembly=:::no-loc(Xamarin.Forms):::.Core">

android:WebView.EnableZoomControls="true"

android:WebView.DisplayZoomControls="true" />

WebView.EnableZoomControls可绑定属性控制是否在上启用了 "缩小到缩放" WebView ，并 WebView.DisplayZoomControls 控制是否在上覆盖缩放控件 WebView 。The WebView.EnableZoomControls bindable property controls whether pinch-to-zoom is enabled on the WebView, and the WebView.DisplayZoomControls bindable property controls whether zoom controls are overlaid on the WebView.

或者，可以使用 Fluent API 从 c # 中使用特定于平台的：Alternatively, the platform-specific can be consumed from C# using the fluent API:

using :::no-loc(Xamarin.Forms):::.PlatformConfiguration;

using :::no-loc(Xamarin.Forms):::.PlatformConfiguration.AndroidSpecific;

...

webView.On()

.EnableZoomControls(true)

.DisplayZoomControls(true);

WebView.On方法指定此平台特定的仅在 Android 上运行。The WebView.On method specifies that this platform-specific will only run on Android. The WebView.EnableZoomControls method, in the :::no-loc(Xamarin.Forms):::.PlatformConfiguration.AndroidSpecific namespace, is used to control whether pinch-to-zoom is enabled on the WebView. WebView.DisplayZoomControls同一命名空间中的方法用于控制缩放控件是否在上重叠 WebView 。The WebView.DisplayZoomControls method, in the same namespace, is used to control whether zoom controls are overlaid on the WebView. 此外， WebView.ZoomControlsEnabled 和 WebView.ZoomControlsDisplayed 方法可用于分别返回是否启用了 "缩小到缩放" 和 "缩放" 控件。In addition, the WebView.ZoomControlsEnabled and WebView.ZoomControlsDisplayed methods can be used to return whether pinch-to-zoom and zoom controls are enabled, respectively.

因此，可以在上启用 "缩小到缩放 WebView "，并在上重叠缩放控件 WebView ：The result is that pinch-to-zoom can be enabled on a WebView, and zoom controls can be overlaid on the WebView:

重要

缩放控件必须通过各自的可绑定属性或方法启用和显示，才能在上重叠 WebView 。Zoom controls must be both enabled and displayed, via the respective bindable properties or methods, to be overlaid on a WebView.

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