如何在openlayers 3.9.0上设置引导进度条

Question

我想显示一个进度条时，直到层加载在打开层3.9.0，任何提示或方向将有所帮助。

Answer 1

应该是这样的：

var
    tile_loading = 0, 
    tile_loaded = 0, 
    tiles_loaded_all = false
;
yourTileLayer.getSource().on('tileloadstart', function(evt){
    ++tile_loading;
});
yourTileLayer.getSource().on('tileloadend', function(evt){
    ++tile_loaded;
    if(tile_loaded === tile_loading){
        tile_loading = 0;
        tile_loaded = 0;
        tiles_loaded_all = true;


    }
});

官方例子- http://openlayers.org/en/v3.9.0/examples/tile-load-events.html