How to set width align ImageView

When the display image, the aspect ratio of the screen and the aspect ratio of the picture is not the same, only to fill the width in the height direction of the screen other than as may be, or may not be covered with the screen, but the aspect ratio of the picture remains changed.

How to set parameters?
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With matrix geometric bloom, but the estimated edge bloom picture is black
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android: adjustViewBounds = "true"
android: layout_width = "wrap_content"
android: layout_height = "wrap_content"
android: maxWidth = screen width
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Upstairs, the "screen width" can not write go die?
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reference to the third floor vnking reply:

Upstairs, the "screen width" can not write go die?

Caesar first try
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android: layout_width = "fill_parent"
android: layout_height = "wrap_content"
android: scaleType = "fitStart"